# kb

id: glossmeter-20260505-1
file: data/en.wikipedia.org/wiki/Glossmeter-1.md
category: reference
title: Glossmeter
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Glossmeter
date_saved: 2026-05-05T09:43:10.484367+00:00
instance: kb-cron
parent: glossmeter-20260505-0
summary:
For example, if the measurement made at 60° is greater than 70 GU, the measurement angle should be changed to 20° to optimise measurement accuracy. Three types of instruments are available on the market: 60° single angle instruments, a combination of 20° and 60° and one type that combines 20°, 60° and 85°. Two additional angles are used for other materials. An angle of 45° is specified for the measurement of ceramics, films, textiles and anodised aluminium, whilst 75° is specified for paper and printed materials. == Gloss units == The measurement scale, gloss units (GU), of a glossmeter is a scaling based on a highly polished reference black glass standard with a defined refractive index having a specular reflectance of 100GU at the specified angle. This standard is used to establish an upper point calibration of 100 with the lower end point established at 0 on a perfectly matte surface. This scaling is suitable for most non-metallic coatings and materials (paints and plastics) as they generally fall within this range. For other materials, highly reflective in appearance (mirrors, plated / raw metal components), higher values can be achieved reaching 2000 Gloss Units. For transparent materials, these values can also


id: haze-meter-20260505-0
file: data/en.wikipedia.org/wiki/Haze_meter-0.md
category: reference
title: Haze meter
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Haze_meter
date_saved: 2026-05-05T09:43:11.625842+00:00
instance: kb-cron
parent: haze-meter-20260505-0
summary:
A haze meter measures the amount of light that is diffused or scattered when passing through a transparent material. Transparency is important because a material needs to be more or less see-through depending on its practical usage, e.g. a grocery bag needs the light to be more diffused so that less can be seen while food packaging film needs the light to be less diffused so that the contents can be seen clearly. For reasons such as these haze meters are necessary to determine which material is needed for which practical purpose. Haze is measured with a wide angle scattering test in which light is diffused in all directions which results in a loss of contrast. That percentage of light that when passing through that deviates from the incident beam by greater than 2.5 degrees on average is defined as haze See through quality is measured with a narrow angle scattering test in which light is diffused in a small range with high concentration. This test measures the clarity with which finer details can be seen through the object being tested. The haze meter also measures total transmittance. Total transmittance is the measure of the total incident light compared to


id: hilger-watts-20260505-0
file: data/en.wikipedia.org/wiki/Hilger_&_Watts-0.md
category: reference
title: Hilger & Watts
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Hilger_&_Watts
date_saved: 2026-05-05T09:43:12.767255+00:00
instance: kb-cron
parent: hilger-watts-20260505-0
summary:
Hilger & Watts was a well-known British manufacturing company that made theodolites and scientific instruments. == History == It was founded on 20 February 1948 when Adam Hilger, Ltd, founded in 1874, merged with Messrs E. R. Watts and Son by Edwin Richard Watts (1833–1901) and George William Watts (c. 1871–1954), founded in 1865. The company was taken over by the Rank Organisation in 1969 and later sold on. == Structure == It employed around 1,300 people in six factories in the late 1940s. It was situated on Camberwell Road (A215 road) in Camberwell, near the junction with the B214, between Walworth (to the north) and Camberwell (to the south) on the western edge of Burgess Park, now part of the London Borough of Southwark. There was a factory in Highbury, together with the head office in Camden Town and a small factory situated between Margate and Ramsgate in Kent. These locations were primarily "Hilger" products, whereas Camberwell was primarily Watts products. The company also had a factory at Loughton (Debden) in Essex == Products == Optical instruments Photometers Theodolite and surveying equipment Tripods Computer controlled X-ray diffractometers Amongst other devices, the Camden location produced PDP-8 computer-driven X-ray diffractometers in


id: hydroscope-20260505-0
file: data/en.wikipedia.org/wiki/Hydroscope-0.md
category: reference
title: Hydroscope
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Hydroscope
date_saved: 2026-05-05T09:43:13.924162+00:00
instance: kb-cron
parent: hydroscope-20260505-0
summary:
A hydroscope is any of several instruments related to water: One kind is an instrument for making observations below the surface of water, such as a long tube fitted with various lenses arranged so that objects lying at the bottom can be reflected upon a screen on the deck of the ship that carries it. These are built with a large tire tube that supports the screen and covered by an acrylic dome for protection. Another kind detects subsurface water through nuclear magnetic resonance using the surface nuclear magnetic resonance technique. An instrument (likely a hydrometer) described by Synesius in his Letter 15 to Hypatia, written in 402 AD. There are references to such instruments as early as the fourth century. Another ancient Greek instrument: a water clock or clepsydra. == Sources and notes ==


id: interferometry-20260505-0
file: data/en.wikipedia.org/wiki/Interferometry-0.md
category: reference
title: Interferometry
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Interferometry
date_saved: 2026-05-05T09:43:15.174742+00:00
instance: kb-cron
parent: interferometry-20260505-0
summary:
Interferometry is a technique which uses the interference of superimposed waves to extract information. Interferometry typically uses electromagnetic waves and is an important investigative technique in the fields of astronomy, fiber optics, engineering metrology, optical metrology, oceanography, seismology, spectroscopy (and its applications to chemistry), quantum mechanics, nuclear and particle physics, plasma physics, biomolecular interactions, surface profiling, microfluidics, mechanical stress/strain measurement, velocimetry, optometry, and making holograms. Interferometers are devices that extract information from interference. They are widely used in science and industry for the measurement of microscopic displacements, refractive index changes and surface irregularities. In the case with most interferometers, light from a single source is split into two beams that travel in different optical paths, which are then combined again to produce interference; two incoherent sources can also be made to interfere under some circumstances. The resulting interference fringes give information about the difference in optical path lengths. In analytical science, interferometers are used to measure lengths and the shape of optical components with nanometer precision; they are the highest-precision length measuring instruments in existence. In Fourier transform spectroscopy they are used to analyze light containing features of absorption or emission associated with a substance or mixture. An astronomical interferometer


id: interferometry-20260505-1
file: data/en.wikipedia.org/wiki/Interferometry-1.md
category: reference
title: Interferometry
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Interferometry
date_saved: 2026-05-05T09:43:15.174742+00:00
instance: kb-cron
parent: interferometry-20260505-0
summary:
== History == The law of interference of light was described by Thomas Young in his 1803 Bakerian Lecture to the Royal Society of London. In preparation for the lecture, Young performed a double-aperture experiment in a water ripple tank. His interpretation in terms of the interference of waves was rejected by most scientists at the time because of the dominance of Isaac Newton's corpuscular theory of light proposed a century before. The French engineer Augustin-Jean Fresnel, unaware of Young's results, began working on a wave theory of light and interference and was introduced to François Arago. Between 1816 and 1818, Fresnel and Arago performed interference experiments at the Paris Observatory. During this time, Arago designed and built the first interferometer, using it to measure the refractive index of moist air relative to dry air, which posed a potential problem for astronomical observations of star positions. The success of Fresnel's wave theory of light was established in his prize-winning memoire of 1819 that predicted and measured diffraction patterns. The Arago interferometer was later employed in 1850 by Leon Foucault to measure the speed of light in air relative to water, and it was used again in 1851 by Hippolyte Fizeau


id: interferometry-20260505-2
file: data/en.wikipedia.org/wiki/Interferometry-2.md
category: reference
title: Interferometry
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Interferometry
date_saved: 2026-05-05T09:43:15.174742+00:00
instance: kb-cron
parent: interferometry-20260505-0
summary:
In 1803, Young's interference experiment played a major role in the general acceptance of the wave theory of light. If white light is used in Young's experiment, the result is a white central band of constructive interference corresponding to equal path length from the two slits, surrounded by a symmetrical pattern of colored fringes of diminishing intensity. In addition to continuous electromagnetic radiation, Young's experiment has been performed with individual photons, with electrons, and with buckyball molecules large enough to be seen under an electron microscope. Lloyd's mirror generates interference fringes by combining direct light from a source (blue lines) and light from the source's reflected image (red lines) from a mirror held at grazing incidence. The result is an asymmetrical pattern of fringes. The band of equal path length, nearest the mirror, is dark rather than bright. In 1834, Humphrey Lloyd interpreted this effect as proof that the phase of a front-surface reflected beam is inverted. ==== Amplitude-splitting inferometers ==== An amplitude splitting interferometer uses a partial reflector to divide the amplitude of the incident wave into separate beams which are separated and recombined. The Fizeau interferometer is shown as it might be set up to test an optical


id: interferometry-20260505-3
file: data/en.wikipedia.org/wiki/Interferometry-3.md
category: reference
title: Interferometry
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Interferometry
date_saved: 2026-05-05T09:43:15.174742+00:00
instance: kb-cron
parent: interferometry-20260505-0
summary:
In physics, one of the most important experiments of the late 19th century was the famous "failed experiment" of Michelson and Morley which provided evidence for special relativity. Recent repetitions of the Michelson–Morley experiment perform heterodyne measurements of beat frequencies of crossed cryogenic optical resonators. Fig 7 illustrates a resonator experiment performed by Müller et al. in 2003. Two optical resonators constructed from crystalline sapphire, controlling the frequencies of two lasers, were set at right angles within a helium cryostat. A frequency comparator measured the beat frequency of the combined outputs of the two resonators. As of 2009, the precision by which anisotropy of the speed of light can be excluded in resonator experiments is at the 10−17 level. Michelson interferometers are used in tunable narrow band optical filters and as the core hardware component of Fourier transform spectrometers. When used as a tunable narrow band filter, Michelson interferometers exhibit a number of advantages and disadvantages when compared with competing technologies such as Fabry–Pérot interferometers or Lyot filters. Michelson interferometers have the largest field of view for a specified wavelength, and are relatively simple in operation, since tuning is via mechanical rotation of waveplates rather than via high voltage control


id: interferometry-20260505-4
file: data/en.wikipedia.org/wiki/Interferometry-4.md
category: reference
title: Interferometry
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Interferometry
date_saved: 2026-05-05T09:43:15.174742+00:00
instance: kb-cron
parent: interferometry-20260505-0
summary:
Astronomical optical interferometry has had to overcome a number of technical issues not shared by radio telescope interferometry. The short wavelengths of light necessitate extreme precision and stability of construction. For example, spatial resolution of 1 milliarcsecond requires 0.5 μm stability in a 100 m baseline. Optical interferometric measurements require high sensitivity, low noise detectors that did not become available until the late 1990s. Astronomical "seeing", the turbulence that causes stars to twinkle, introduces rapid, random phase changes in the incoming light, requiring data collection rates to be faster than the rate of turbulence. Despite these technical difficulties, three major facilities are now in operation offering resolutions down to the fractional milliarcsecond range. The wave character of matter can be exploited to build interferometers. The first examples of matter interferometers were electron interferometers, later followed by neutron interferometers. Around 1990 the first atom interferometers were demonstrated, later followed by interferometers employing molecules. Electron holography is an imaging technique that photographically records the electron interference pattern of an object, which is then reconstructed to yield a greatly magnified image of the original object. This technique was developed to enable greater resolution in electron microscopy than is possible using conventional imaging techniques.


id: interferometry-20260505-5
file: data/en.wikipedia.org/wiki/Interferometry-5.md
category: reference
title: Interferometry
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Interferometry
date_saved: 2026-05-05T09:43:15.174742+00:00
instance: kb-cron
parent: interferometry-20260505-0
summary:
The Twyman–Green interferometer, invented by Twyman and Green in 1916, is a variant of the Michelson interferometer widely used to test optical components. The basic characteristics distinguishing it from the Michelson configuration are the use of a monochromatic point light source and a collimator. Michelson (1918) criticized the Twyman–Green configuration as being unsuitable for the testing of large optical components, since the light sources available at the time had limited coherence length. Michelson pointed out that constraints on geometry forced by limited coherence length required the use of a reference mirror of equal size to the test mirror, making the Twyman–Green impractical for many purposes. Decades later, the advent of laser light sources answered Michelson's objections. (A Twyman–Green interferometer using a laser light source and unequal path length is known as a Laser Unequal Path Interferometer, or LUPI.) Fig. 14 illustrates a Twyman–Green interferometer set up to test a lens. Light from a monochromatic point source is expanded by a diverging lens (not shown), then is collimated into a parallel beam. A convex spherical mirror is positioned so that its center of curvature coincides with the focus of the lens being tested. The emergent beam is recorded by an imaging


id: interferometry-20260505-6
file: data/en.wikipedia.org/wiki/Interferometry-6.md
category: reference
title: Interferometry
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Interferometry
date_saved: 2026-05-05T09:43:15.174742+00:00
instance: kb-cron
parent: interferometry-20260505-0
summary:
Optical heterodyne detection is an essential technique used in high-accuracy measurements of the frequencies of optical sources, as well as in the stabilization of their frequencies. Until relatively few years ago, lengthy frequency chains were needed to connect the microwave frequency of a cesium or other atomic time source to optical frequencies. At each step of the chain, a frequency multiplier would be used to produce a harmonic of the frequency of that step, which would be compared by heterodyne detection with the next step (the output of a microwave source, far infrared laser, infrared laser, or visible laser). Each measurement of a single spectral line required several years of effort in the construction of a custom frequency chain. Currently, optical frequency combs have provided a much simpler method of measuring optical frequencies. If a mode-locked laser is modulated to form a train of pulses, its spectrum is seen to consist of the carrier frequency surrounded by a closely spaced comb of optical sideband frequencies with a spacing equal to the pulse repetition frequency (Fig. 16). The pulse repetition frequency is locked to that of the frequency standard, and the frequencies of the comb elements at the red end of


id: interferometry-20260505-7
file: data/en.wikipedia.org/wiki/Interferometry-7.md
category: reference
title: Interferometry
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Interferometry
date_saved: 2026-05-05T09:43:15.174742+00:00
instance: kb-cron
parent: interferometry-20260505-0
summary:
In coherence scanning interferometry, interference is only achieved when the path length delays of the interferometer are matched within the coherence time of the light source. CSI monitors the fringe contrast rather than the phase of the fringes. Fig. 17 illustrates a CSI microscope using a Mirau interferometer in the objective; other forms of interferometer used with white light include the Michelson interferometer (for low magnification objectives, where the reference mirror in a Mirau objective would interrupt too much of the aperture) and the Linnik interferometer (for high magnification objectives with limited working distance). The sample (or alternatively, the objective) is moved vertically over the full height range of the sample, and the position of maximum fringe contrast is found for each pixel. The chief benefit of coherence scanning interferometry is that systems can be designed that do not suffer from the 2 pi ambiguity of coherent interferometry, and as seen in Fig. 18, which scans a 180μm x 140μm x 10μm volume, it is well suited to profiling steps and rough surfaces. The axial resolution of the system is determined in part by the coherence length of the light source. Industrial applications include in-process surface metrology, roughness measurement, 3D


id: interferometry-20260505-8
file: data/en.wikipedia.org/wiki/Interferometry-8.md
category: reference
title: Interferometry
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Interferometry
date_saved: 2026-05-05T09:43:15.174742+00:00
instance: kb-cron
parent: interferometry-20260505-0
summary:
Interferometric synthetic aperture radar (InSAR) is a radar technique used in geodesy and remote sensing. Satellite synthetic aperture radar images of a geographic feature are taken on separate days, and changes that have taken place between radar images taken on the separate days are recorded as fringes similar to those obtained in holographic interferometry. The technique can monitor centimeter- to millimeter-scale deformation resulting from earthquakes, volcanoes and landslides, and also has uses in structural engineering, in particular for the monitoring of subsidence and structural stability. Fig 20 shows Kilauea, an active volcano in Hawaii. Data acquired using the space shuttle Endeavour's X-band Synthetic Aperture Radar on April 13, 1994 and October 4, 1994 were used to generate interferometric fringes, which were overlaid on the X-SAR image of Kilauea. Electronic speckle pattern interferometry (ESPI), also known as TV holography, uses video detection and recording to produce an image of the object upon which is superimposed a fringe pattern which represents the displacement of the object between recordings. (see Fig. 21) The fringes are similar to those obtained in holographic interferometry. When lasers were first invented, laser speckle was considered to be a severe drawback in using lasers to illuminate objects, particularly


id: interferometry-20260505-9
file: data/en.wikipedia.org/wiki/Interferometry-9.md
category: reference
title: Interferometry
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Interferometry
date_saved: 2026-05-05T09:43:15.174742+00:00
instance: kb-cron
parent: interferometry-20260505-0
summary:
Phase contrast and differential interference contrast (DIC) microscopy are important tools in biology and medicine. Most animal cells and single-celled organisms have very little color, and their intracellular organelles are almost totally invisible under simple bright field illumination. These structures can be made visible by staining the specimens, but staining procedures are time-consuming and kill the cells. As seen in Figs. 24 and 25, phase contrast and DIC microscopes allow unstained, living cells to be studied. DIC also has non-biological applications, for example in the analysis of planar silicon semiconductor processing. Angle-resolved low-coherence interferometry (a/LCI) uses scattered light to measure the sizes of subcellular objects, including cell nuclei. This allows interferometry depth measurements to be combined with density measurements. Various correlations have been found between the state of tissue health and the measurements of subcellular objects. For example, it has been found that as tissue changes from normal to cancerous, the average cell nuclei size increases. Phase-contrast X-ray imaging (Fig. 26) refers to a variety of techniques that use phase information of a coherent x-ray beam to image soft tissues. (For an elementary discussion, see Phase-contrast x-ray imaging (introduction). For a more in-depth review, see Phase-contrast X-ray imaging.) It has


id: level-optical-instrument-20260505-0
file: data/en.wikipedia.org/wiki/Level_(optical_instrument)-0.md
category: reference
title: Level (optical instrument)
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Level_(optical_instrument)
date_saved: 2026-05-05T09:43:16.386089+00:00
instance: kb-cron
parent: level-optical-instrument-20260505-0
summary:
A level is an optical instrument used to establish or verify points in the same horizontal plane in a process known as levelling. It is used in conjunction with a levelling staff to establish the relative height or levels (the vertical separation) of objects or marks. It is widely used in surveying and construction to measure height differences and to transfer, measure, and set heights of known objects or marks. It is also known as a surveyor's level, builder's level, dumpy level or the historic "Y level". It operates on the principle of establishing a visual level relationship between two or more points, for which an inbuilt optical telescope and a highly accurate bubble level are used to achieve the necessary accuracy. Traditionally the instrument was completely adjusted manually to ensure a level line of sight, but modern automatic versions self-compensate for slight errors in the coarse levelling of the instrument, and are thereby quicker to use. The optical level should not be confused with a theodolite, which can also measure angles in the vertical plane. == Description == The complete unit is normally mounted on a tripod, and the telescope can freely rotate 360° in a horizontal plane. The


id: level-optical-instrument-20260505-1
file: data/en.wikipedia.org/wiki/Level_(optical_instrument)-1.md
category: reference
title: Level (optical instrument)
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Level_(optical_instrument)
date_saved: 2026-05-05T09:43:16.386089+00:00
instance: kb-cron
parent: level-optical-instrument-20260505-0
summary:
An automatic level, self-levelling level, or builder's auto level includes an internal compensator mechanism (a swinging prism) that, when set close to level, automatically removes any remaining variation. This reduces the need to set the instrument base truly level, as with a dumpy level. Self-levelling instruments are the preferred instrument on building sites, construction, and during surveying due to ease of use and rapid setup time. The world's first automatic level was introduced on 8 March 1950. It was produced by the German company Zeiss-Opton in Oberkochen. Main components of an automatic level include a tribrach – a lower, fixed, triangular or circular element containing three sockets for adjusting screws (or wedge rings), attached to the tripod with a heart screw – and an alidade – a movable (rotatable) part. In automatic levels, the spirit level is most often replaced by a pendulum-based opto-mechanical device called a compensator. === Digital electronic level === A digital electronic level is also set level on a tripod and reads a bar-coded staff using electronic laser methods. The height of the staff where the level beam crosses the staff is shown on a digital display. This type of level removes interpolation of graduation by


id: list-of-viewing-instruments-20260505-0
file: data/en.wikipedia.org/wiki/List_of_viewing_instruments-0.md
category: reference
title: List of viewing instruments
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/List_of_viewing_instruments
date_saved: 2026-05-05T09:43:17.548748+00:00
instance: kb-cron
parent: list-of-viewing-instruments-20260505-0
summary:
A viewing instrument is a type of optical instrument that is used to assist viewing or visually examining an object or scenery. == Types == == References ==


id: lovibond-comparator-20260505-0
file: data/en.wikipedia.org/wiki/Lovibond_comparator-0.md
category: reference
title: Lovibond comparator
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Lovibond_comparator
date_saved: 2026-05-05T09:43:18.709605+00:00
instance: kb-cron
parent: lovibond-comparator-20260505-0
summary:
The Lovibond comparator is an example of a colorimeter made in Britain by The Tintometer Ltd. It was invented in the 19th century by Joseph Williams Lovibond, a British brewer and chemist, as a tool to standardize the production of beer. Updated versions are still available. == Description == The device is used to determine the color of liquids. A sample is put in a glass tube. The tube is inserted in the comparator and compared with a series of colored glass discs until the nearest possible match is found. Among other things, the device is used to determine the concentration of certain chemicals in solution. In this use, some assumptions are made about what is in the sample. Given those assumptions, the concentration will be indicated by the disc which best matches the color of the solution. There are a number of standard tests in which a sample to be tested is mixed with a color reagent. In such tests, the resulting color indicates the concentration of the sample under test (see Beer–Lambert law). Results can be approximate, compared to other testing techniques, but the comparator is useful for field work because it is portable, rugged and easy to


id: mirror-galvanometer-20260505-0
file: data/en.wikipedia.org/wiki/Mirror_galvanometer-0.md
category: reference
title: Mirror galvanometer
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Mirror_galvanometer
date_saved: 2026-05-05T09:43:19.898895+00:00
instance: kb-cron
parent: mirror-galvanometer-20260505-0
summary:
A mirror galvanometer is an ammeter that indicates it has sensed an electric current by deflecting a light beam with a mirror. The beam of light projected on a scale acts as a long massless pointer. In 1826, Johann Christian Poggendorff developed the mirror galvanometer for detecting electric currents. The apparatus is also known as a spot galvanometer after the spot of light produced in some models. Mirror galvanometers were used extensively in scientific instruments before reliable, stable electronic amplifiers were available. The most common uses were as recording equipment for seismometers and submarine cables used for telegraphy. In modern times, the term mirror galvanometer is also used for devices that move laser beams by rotating a mirror through a galvanometer set-up, often with a servo-like control loop. The name is often abbreviated as galvo. == Kelvin's galvanometer == The mirror galvanometer was improved significantly by William Thomson, later to become Lord Kelvin. He coined the term mirror galvanometer and patented the device in 1858. Thomson intended the instrument to read weak signal currents on very long submarine telegraph cables. This instrument was far more sensitive than any which preceded it, enabling the detection of the slightest defect in the


id: mirror-galvanometer-20260505-1
file: data/en.wikipedia.org/wiki/Mirror_galvanometer-1.md
category: reference
title: Mirror galvanometer
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Mirror_galvanometer
date_saved: 2026-05-05T09:43:19.898895+00:00
instance: kb-cron
parent: mirror-galvanometer-20260505-0
summary:
Moving coil galvanometer was developed independently by Marcel Deprez and Jacques-Arsène d'Arsonval about 1880. Deprez's galvanometer was developed for high currents, while D'Arsonval designed his to measure weak currents. Unlike in the Kelvin's galvanometer, in this type of galvanometer the magnet is stationary and the coil is suspended in the magnet gap. The mirror attached to the coil frame rotates together with it. This form of instrument can be more sensitive and accurate and it replaced the Kelvin's galvanometer in most applications. The moving coil galvanometer is practically immune to ambient magnetic fields. Another important feature is self-damping generated by the electro-magnetic forces due to the currents induced in the coil by its movements the magnetic field. These are proportional to the angular velocity of the coil. == Modern uses == In modern times, high-speed mirror galvanometers are employed in laser light shows to move the laser beams and produce colorful geometric patterns in fog around the audience. Such high speed mirror galvanometers have proved to be indispensable in industry for laser marking systems for everything from laser etching hand tools, containers, and parts to batch-coding semiconductor wafers in semiconductor device fabrication. They typically control X and Y directions on


id: n-slit-interferometer-20260505-0
file: data/en.wikipedia.org/wiki/N-slit_interferometer-0.md
category: reference
title: N-slit interferometer
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/N-slit_interferometer
date_saved: 2026-05-05T09:43:21.075248+00:00
instance: kb-cron
parent: n-slit-interferometer-20260505-0
summary:
The N-slit interferometer is an extension of the double-slit interferometer also known as Young's double-slit interferometer. One of the first known uses of N-slit arrays in optics was illustrated by Newton. In the first part of the twentieth century, Michelson described various cases of N-slit diffraction. Feynman described thought experiments the explored two-slit quantum interference of electrons, using Dirac's notation. This approach was extended to N-slit interferometers, by Duarte and colleagues in 1989, using narrow-linewidth laser illumination, that is, illumination by indistinguishable photons. The first application of the N-slit interferometer was the generation and measurement of complex interference patterns. These interferograms are accurately reproduced, or predicted, by the N-slit interferometric equation for either even (N = 2, 4, 6,...), or odd (N = 3, 5, 7,...), numbers of slits. == N-slit laser interferometer == The N-slit laser interferometer, introduced by Duarte, uses prismatic beam expansion to illuminate a transmission grating, or N-slit array, and a photoelectric detector array (such as a CCD or CMOS) at the interference plane to register the interferometric signal. The expanded laser beam illuminating the N-slit array is single-transverse-mode and narrow-linewidth. This beam can also take the shape, via the introduction of a convex lens prior


id: optical-correlator-20260505-0
file: data/en.wikipedia.org/wiki/Optical_correlator-0.md
category: reference
title: Optical correlator
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Optical_correlator
date_saved: 2026-05-05T09:43:22.231203+00:00
instance: kb-cron
parent: optical-correlator-20260505-0
summary:
An optical correlator is an optical computer for comparing two signals by utilising the Fourier transforming properties of a lens. It is commonly used in optics for target tracking and identification. == Introduction == The correlator has an input signal which is multiplied by some filter in the Fourier domain. An example filter is the matched filter which uses the cross correlation of the two signals. The cross correlation or correlation plane, c ( x , y ) {\displaystyle c(x,y)} of a 2D signal i ( x , y ) {\displaystyle i(x,y)} with h ( x , y ) {\displaystyle h(x,y)} is c ( x , y ) = i ( x , y ) ⊗ h ∗ ( − x , − y ) {\displaystyle c(x,y)=i(x,y)\otimes h^{*}(-x,-y)} This can be re-expressed in Fourier space as C ( ξ , η ) = I ( ξ , η ) H ∗ ( − ξ , − η ) {\displaystyle C(\xi ,\eta )=I(\xi ,\eta )H^{*}(-\xi ,-\eta )} where the capital letters denote the Fourier transform of what the lower case letter denotes. So the correlation can then be calculated by inverse Fourier transforming the result. == Implementation == According to Fresnel


id: optical-power-meter-20260505-0
file: data/en.wikipedia.org/wiki/Optical_power_meter-0.md
category: reference
title: Optical power meter
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Optical_power_meter
date_saved: 2026-05-05T09:43:23.426777+00:00
instance: kb-cron
parent: optical-power-meter-20260505-0
summary:
An optical power meter (OPM) is a device used to measure the power in an optical signal. The term usually refers to a device for testing average power in fiber optic systems. Other general purpose light power measuring devices are usually called radiometers, photometers, laser power meters (can be photodiode sensors or thermopile laser sensors), light meters or lux meters. A typical optical power meter consists of a calibrated sensor, measuring amplifier and display. The sensor primarily consists of a photodiode selected for the appropriate range of wavelengths and power levels. On the display unit, the measured optical power and set wavelength is displayed. Power meters are calibrated using a traceable calibration standard. A traditional optical power meter responds to a broad spectrum of light, however, the calibration is wavelength dependent. This is not normally an issue, since the test wavelength is usually known, however, it has a couple of drawbacks. Firstly, the user must set the meter to the correct test wavelength, and secondly, if there are other spurious wavelengths present, then wrong readings will result. Optical power meters are available as stand-alone bench or handheld instruments or combined with other test functions such as an Optical Light Source


id: optical-power-meter-20260505-1
file: data/en.wikipedia.org/wiki/Optical_power_meter-1.md
category: reference
title: Optical power meter
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Optical_power_meter
date_saved: 2026-05-05T09:43:23.426777+00:00
instance: kb-cron
parent: optical-power-meter-20260505-0
summary:
== Calibration and accuracy == Optical Power Meter calibration and accuracy is a contentious issue. The accuracy of most primary reference standards (e.g. Weight, Time, Length, Volt, etc.) is known to a high accuracy, typically of the order of 1 part in a billion. However the optical power standards maintained by various National Standards Laboratories, are only defined to about one part in a thousand. By the time this accuracy has been further degraded through successive links, instrument calibration accuracy is usually only a few %. The most accurate field optical power meters claim 1% calibration accuracy. This is orders of magnitude less accurate than a comparable electrical meter. Calibration processes for optical power meters are given in IEC 61315 Ed. 3.0 b:2019 - Calibration of fibre-optic power meters. Furthermore, the in-use accuracy achieved is usually significantly lower than the claimed calibration accuracy, by the time additional factors are taken into account. In typical field applications, factors may include: ambient temperature, optical connector type, wavelength variations, linearity variations, beam geometry variations, detector saturation. Therefore, achieving a good level of practical instrument accuracy and linearity is something that requires design skill, and high manufacturing proficiency. With the increasing global importance in


id: perspective-machine-20260505-0
file: data/en.wikipedia.org/wiki/Perspective_machine-0.md
category: reference
title: Perspective machine
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Perspective_machine
date_saved: 2026-05-05T09:43:24.616799+00:00
instance: kb-cron
parent: perspective-machine-20260505-0
summary:
A perspective machine is an optical instrument designed to help artists create perspective drawings. The earliest machines were built centuries ago when the theory of perspective was being worked out, and modern versions are still in use. == Timeline == 1510: Leonardo da Vinci's Draftsman drawing an armillary sphere shows an early form of perspective machine in use. 1525: Albrecht Dürer, in his illustration Man drawing a lute, shows an artist using a perspective machine to create a drawing. The machine consists of a wooden frame with a taut string passing through it to represent the viewer's line of sight. Dürer built his second model of such a machine in the same year. c.1765: Scottish engineer James Watt designs a machine based on an easel, with a pantograph mechanism allowing the artist to trace an object using a sight arm and transfer the movement of the sight to a pen drawing on paper. Watt stated that his machine was based on an invention by a Mr Hurst, who lived in India. 1763: Philosopher Thomas Reid uses a machine to investigate his theory of perception. 1825: English inventor Francis Ronalds patents two perspective tracing machines. One generated an accurate drawing of


id: photometer-20260505-0
file: data/en.wikipedia.org/wiki/Photometer-0.md
category: reference
title: Photometer
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Photometer
date_saved: 2026-05-05T09:43:26.920738+00:00
instance: kb-cron
parent: photometer-20260505-0
summary:
A photometer is an instrument for measuring photometric quantities such as luminous flux, illuminance, or luminance. Historically, photometry was done by estimation, comparing the luminous flux of a source with a standard source. By the 19th century, common photometers included Rumford's photometer, which compared the depths of shadows cast by different light sources, and Ritchie's photometer, which relied on equal illumination of surfaces. Another type was based on the extinction of shadows. Most modern photometers detect light by converting it into an electric current using a photoresistor, photodiode, or photomultiplier. Some models employ photon counting, measuring light by counting individual photons. They are especially useful in areas where the irradiance is low. Photometers have wide-ranging applications including photography, where they determine the correct exposure, and science, where they are used in absorption spectroscopy to calculate the concentration of substances in a solution, infrared spectroscopy to study the structure of substances, and atomic absorption spectroscopy to determine the concentration of metals in a solution. == History == Before electronic light sensitive elements were developed, photometry was done by estimation by the eye. The relative luminous flux of a source was compared with a standard source. The photometer is placed such that


id: photometer-20260505-1
file: data/en.wikipedia.org/wiki/Photometer-1.md
category: reference
title: Photometer
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Photometer
date_saved: 2026-05-05T09:43:26.920738+00:00
instance: kb-cron
parent: photometer-20260505-0
summary:
== Visible light reflectance photometry == A reflectance photometer measures the reflectance of a surface as a function of wavelength. The surface is illuminated with white light, and the reflected light is measured after passing through a monochromator. This type of measurement has mainly practical applications, for instance in the paint industry to characterize the colour of a surface objectively. == UV and visible light transmission photometry == These are optical instruments for measurement of the absorption of light of a given wavelength (or a given range of wavelengths) of coloured substances in solution. From the light absorption, Beer's law makes it possible to calculate the concentration of the coloured substance in the solution. Due to its wide range of application and its reliability and robustness, the photometer has become one of the principal instruments in biochemistry and analytical chemistry. Absorption photometers for work in aqueous solution work in the ultraviolet and visible ranges, from wavelength around 240 nm up to 750 nm. The principle of spectrophotometers and filter photometers is that (as far as possible) monochromatic light is allowed to pass through a container (cell) with optically flat windows containing the solution. It then reaches a light detector, that


id: polarimeter-20260505-0
file: data/en.wikipedia.org/wiki/Polarimeter-0.md
category: reference
title: Polarimeter
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Polarimeter
date_saved: 2026-05-05T09:43:28.106070+00:00
instance: kb-cron
parent: polarimeter-20260505-0
summary:
A polarimeter is a scientific instrument used to measure optical rotation: the angle of rotation caused by passing linearly polarized light through an optically active substance. Some chemical substances are optically active, and linearly polarized (uni-directional) light will rotate either to the left (counter-clockwise) or right (clockwise) when passed through these substances. The amount by which the light is rotated is known as the angle of rotation. The direction (clockwise or counterclockwise) and magnitude of the rotation reveals information about the sample's chiral properties such as the relative concentration of enantiomers present in the sample. == History == Polarization by reflection was discovered in 1808 by Étienne-Louis Malus (1775–1812). == Measuring principle == The ratio, the purity, and the concentration of two enantiomers can be measured via polarimetry. Enantiomers are characterized by their property to rotate the plane of linear polarized light. Therefore, those compounds are called optically active and their property is referred to as optical rotation. Light sources such as a light bulb, Tungsten Halogen, or the sun emit electromagnetic waves at the frequency of visible light. Their electric field oscillates in all possible planes relative to their direction of propagation. In contrast to that, the waves of


id: polarimeter-20260505-1
file: data/en.wikipedia.org/wiki/Polarimeter-1.md
category: reference
title: Polarimeter
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Polarimeter
date_saved: 2026-05-05T09:43:28.106070+00:00
instance: kb-cron
parent: polarimeter-20260505-0
summary:
=== Laurent's half-shade polarimeter === When plane-polarised light passes through some crystals, the velocity of left-polarized light is different from that of the right-polarized light, thus the crystals are said to have two refractive indices, i.e. double refracting. Construction: The polarimeter consists of a monochromatic source S which is placed at focal point of a convex lens L. Just after the convex lens there is a Nicol Prism P which acts as a polariser. H is a half shade device which divides the field of polarized light emerging out of the Nicol P into two halves, generally of unequal brightness. T is a glass tube in which an optically active solution is filled. The light, after passing through T, is allowed to fall on the analyzing Nicol A which can be rotated about the axis of the tube. The rotation of the analyzer can be measured with the help of a scale C. Working principle: To understand the need of a half-shade device, let us suppose that it is not present. The position of the analyzer is adjusted so that the field of view is dark when the tube is empty. The position of the analyzer is noted on the


id: polarimeter-20260505-2
file: data/en.wikipedia.org/wiki/Polarimeter-2.md
category: reference
title: Polarimeter
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Polarimeter
date_saved: 2026-05-05T09:43:28.106070+00:00
instance: kb-cron
parent: polarimeter-20260505-0
summary:
=== Manual === The earliest polarimeters, which date back to the 1830s, required the user to physically rotate one polarizing element (the analyzer) whilst viewing through another static element (the detector). The detector was positioned at the opposite end of a tube containing the optically active sample, and the user used his/her eye to judge the "alignment" when least light was observed. The angle of rotation was then read from a simple fixed to the moving polariser to within a degree or so. Although most manual polarimeters produced today still adopt this basic principle, the many developments applied to the original opto-mechanical design over the years have significantly improved measurement performance. The introduction of a half-wave plate increased "distinction sensitivity", whilst a precision glass scale with vernier drum facilitated the final reading to within ca. ±0.05º. Most modern manual polarimeters also incorporate a long-life yellow LED in place of the more costly sodium arc lamp as a light source. === Semi-automatic === Today, semi-automatic polarimeters are available. The operator views the image via a digital display adjusts the analyzer angle with electronic controls. === Fully automatic === Fully automatic polarimeters are now widely used and simply require the user to


id: polarimeter-20260505-3
file: data/en.wikipedia.org/wiki/Polarimeter-3.md
category: reference
title: Polarimeter
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Polarimeter
date_saved: 2026-05-05T09:43:28.106070+00:00
instance: kb-cron
parent: polarimeter-20260505-0
summary:
=== Chemical industry === Many chemicals exhibit a specific rotation as a unique property (an intensive property like refractive index or specific gravity) which can be used to distinguish it. Polarimeters can identify unknown samples based on this if other variables such as concentration and length of sample cell length are controlled or at least known. This is used in the chemical industry. By the same token, if the specific rotation of a sample is already known, then the concentration and/or purity of a solution containing it can be calculated. Most automatic polarimeters make this calculation automatically, given input on variables from the user. === Food, beverage and pharmaceutical industries === Concentration and purity measurements are especially important to determine product or ingredient quality in the food & beverage and pharmaceutical industries. Samples that display specific rotations that can be calculated for purity with a polarimeter include: Polarimeters are used in the sugar industry for determining quality of both juice from sugar cane and the refined sucrose. Often, the sugar refineries use a modified polarimeter with a flow cell (and used in conjunction with a refractometer) called a saccharimeter. These instruments use the International Sugar Scale, as defined by the


id: post-instrument-20260505-0
file: data/en.wikipedia.org/wiki/Post_Instrument-0.md
category: reference
title: Post Instrument
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Post_Instrument
date_saved: 2026-05-05T09:43:29.277739+00:00
instance: kb-cron
parent: post-instrument-20260505-0
summary:
The Post Plotting Instrument, or simply Post Instrument and sometimes the Observer Instrument, was the standard optical sighting system used by the UK's Royal Observer Corps (ROC) to determine the location of aircraft. It was used during the period from the mid-1930s into the early 1950s, and was one of the main sources of daytime tracking information during World War II. There were two versions of the Post Instrument, a pre-war model using a pantograph, and a wartime version of somewhat more sophistication. Both required the operator to estimate the altitude of the aircraft and enter that into the device, then point a mechanical indicator, or sight, at the aircraft. The motion of the sight moved an indicator on a small Ordnance Survey National Grid map. The grid location indicated by the pointer was then telephoned to central control rooms, where several such reports were combined to produce a more accurate location estimate. Later models added the Micklethwait Height Corrector, which allowed the posts to measure altitude with some accuracy and thus improve the quality of the measurements. The ROC also developed a methodology that allowed the Post Instrument to be used to produce measurements purely by sound, but it


id: post-instrument-20260505-1
file: data/en.wikipedia.org/wiki/Post_Instrument-1.md
category: reference
title: Post Instrument
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Post_Instrument
date_saved: 2026-05-05T09:43:29.277739+00:00
instance: kb-cron
parent: post-instrument-20260505-0
summary:
== Micklethwait Height Corrector == Wartime models were modified in 1940 with the Micklethwait Height Corrector, named for its inventor, Eric Walter Eustace Micklethwait. Micklethwait was an observer at the Gower Street Post on the roof of a building at University of London, near Euston Square tube station. Formerly a patent clerk, he devised the Corrector and quickly patented it. The Corrector consisted of a second map pointer on a second horizontal slider, with a crank that moved the horizontal slider fore and aft. A second arm suspended from the main sight tube was pushed up and down as the horizontal portion slid. This arm was measured against a short vertical bar marked with altitude corrections. The system indicated only corrections, not the actual altitude. Two or more posts had to work in concert to use the system, using two measured angles and simple trigonometry to solve the altitude. The simplest measurement took place when an aircraft flew directly over one of the posts. Other posts that could see the same aircraft would continue to track the target as normal, set to whatever altitude they had initially estimated. When the first post called that the aircraft was directly overhead, the


id: post-instrument-20260505-2
file: data/en.wikipedia.org/wiki/Post_Instrument-2.md
category: reference
title: Post Instrument
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Post_Instrument
date_saved: 2026-05-05T09:43:29.277739+00:00
instance: kb-cron
parent: post-instrument-20260505-0
summary:
The Observer Corp was an expansion of a system originally set up in World War I to coordinate the reports from observers in the London area, part of the London Air Defence Area (LADA). In this system, originally set up by Edward Ashmore, observers telephoned reports of aircraft to a plotting center in the Horse Guards building in London. Information from the map would then be forwarded to the searchlights and anti-aircraft guns in the LADA area. In the post-World War I era the system was taken over by the Air Defence of Great Britain organization, formally part of the Royal Air Force but containing British Army and Royal Engineer units as well. It was re-organized and expanded, covering not only the London area but adding similar reporting organizations in The Midlands. They also introduced new techniques to deal with faster aircraft. In the new systems, plotters would take the reports from the observers and place a colored marker on a large map inside the indicated grid location. The marker held information about the number and altitude of the aircraft. The marker colors changed every five minutes, based on a sector clock, and when the marker was moved to a


id: pseudoscope-20260505-0
file: data/en.wikipedia.org/wiki/Pseudoscope-0.md
category: reference
title: Pseudoscope
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Pseudoscope
date_saved: 2026-05-05T09:43:30.433063+00:00
instance: kb-cron
parent: pseudoscope-20260505-0
summary:
A pseudoscope is a binocular optical instrument that reverses depth perception. It is used to study human stereoscopic perception. Objects viewed through it appear inside out, for example: a box on a floor would appear as a box-shaped hole in the floor. It typically uses sets of optical prisms, or periscopically arranged mirrors to swap the view of the left eye with that of the right eye. == Purpose == In the 1800s Charles Wheatstone coined the name from the Greek ψευδίς σκοπειν – 'false view'. The device was used to explore his theory of stereo vision. Basically, pseudoscopic vision is three-dimensional vision in reverse. For example, in aerial photography, swimming pools appear to look like buildings and buildings appear to look like swimming pools. In red and green plotters like the Kelsh and Multiplex this is achieved by reversing the lenses on the 3D glasses. The images will be reverse order. The right image will be viewed through the left eye, and the left image will be through the right eye. == Effect == Switching the two pictures in a standard stereoscope changes all the elevated parts into depressions, and vice versa. The pseudoscope also changes convex into concave,


id: pyramid-wavefront-sensor-20260505-0
file: data/en.wikipedia.org/wiki/Pyramid_wavefront_sensor-0.md
category: reference
title: Pyramid wavefront sensor
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Pyramid_wavefront_sensor
date_saved: 2026-05-05T09:43:31.620901+00:00
instance: kb-cron
parent: pyramid-wavefront-sensor-20260505-0
summary:
A pyramid wavefront sensor is a type of a wavefront sensor. It measures the optical aberrations of an optical wavefront. This wavefront sensor uses a pyramidal prism with a large apex angle to split the beam into multiple parts at the geometric focus of a lens. A four-faceted prism, with its tip centered at the peak of the point spread function, will generate four identical pupil images in the absence of optical aberrations. In the presence of optical aberrations, the intensity distribution among the pupils will change. The local wavefront gradients can be obtained by recording the distribution of intensity in the pupil images. The wavefront aberrations can be evaluated from the estimated wavefront gradients. It has potential applications in astronomy and ophthalmology. == Modulation == The prism is often modulated (mechanically moved in a circle/square) for averaging purposes and to make sure that the ray spends an equal fraction of the total time on every face of the pyramidal prism. This makes the wavefront sensor slightly inconvenient to use due to the need for mechanically moving parts – either the prism or the beam is modulated. Using a light diffusing plate, mechanically moving parts can be eliminated. Alternatively, it


id: rhinoscope-20260505-0
file: data/en.wikipedia.org/wiki/Rhinoscope-0.md
category: reference
title: Rhinoscope
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Rhinoscope
date_saved: 2026-05-05T09:43:33.971738+00:00
instance: kb-cron
parent: rhinoscope-20260505-0
summary:
A rhinoscope (or nasoscope) is a thin, tube-like instrument used to examine the inside of the nose. A rhinoscope has a light and a lens for viewing and may have a tool to remove tissue. == Types == Rhinoscopy is performed by two procedures. Anterior rhinoscopy using a nasal speculum Posterior rhinoscopy using an endoscopic rhinoscope === Anterior rhinoscopy === In anterior rhinoscopy, the rhinoscope is advanced through the nose to examine the nasal cavity. === Posterior rhinoscopy === In posterior rhinoscopy, the endoscope is advanced through the mouth to examine the back of the nasal cavity above the soft palate, and can be used to visualise the oropharynx below that. Structures seen in posterior rhinoscopy: posterior border of nasal septum, fossa of Roosenmuller, eustachian tube opening and upper surface of soft palate. == References == == External links == Rhinoscope entry in the public domain NCI Dictionary of Cancer Terms This article incorporates public domain material from Dictionary of Cancer Terms. U.S. National Cancer Institute.


id: slit-lamp-20260505-0
file: data/en.wikipedia.org/wiki/Slit_lamp-0.md
category: reference
title: Slit lamp
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Slit_lamp
date_saved: 2026-05-05T09:43:35.131086+00:00
instance: kb-cron
parent: slit-lamp-20260505-0
summary:
In ophthalmology and optometry, a slit lamp is an instrument consisting of a high-intensity light source that can be focused to shine a thin sheet of light into the eye. It is used in conjunction with a biomicroscope. The lamp facilitates an examination of the anterior segment and posterior segment of the human eye, which includes the eyelid, sclera, conjunctiva, iris, natural crystalline lens, and cornea. The binocular slit-lamp examination provides a stereoscopic magnified view of the eye structures in detail, enabling anatomical diagnoses to be made for a variety of eye conditions. A second, hand-held lens is used to examine the retina. == History == Two conflicting trends emerged in the development of the slit lamp. One trend originated from clinical research and aimed to apply the increasingly complex and advanced technology of the time. The second trend originated from ophthalmologic practice and aimed at technical perfection and a restriction to useful methods. The first man credited with developments in this field was Hermann von Helmholtz (1850) when he invented the ophthalmoscope. In ophthalmology and optometry, the instrument is called a "slit lamp", although it is more correctly called a "slit lamp instrument". Today's instrument is a combination of


id: slit-lamp-20260505-1
file: data/en.wikipedia.org/wiki/Slit_lamp-1.md
category: reference
title: Slit lamp
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Slit_lamp
date_saved: 2026-05-05T09:43:35.131086+00:00
instance: kb-cron
parent: slit-lamp-20260505-0
summary:
== General procedure == While a patient is seated in the examination chair, they rest their chin and forehead on a support area to steady the head. Using the biomicroscope, the ophthalmologist or optometrist then proceeds to examine the patient's eye. A fine strip of paper, stained with fluorescein, a fluorescent dye, may be touched to the side of the eye; this stains the tear film on the surface of the eye to aid examination. The dye is naturally rinsed out of the eye by tears. A subsequent test may involve placing drops in the eye in order to dilate the pupils. The drops take about 15 to 20 minutes to work, after which the examination is repeated, allowing the back of the eye to be examined. Patients will experience some light sensitivity for a few hours after this exam, and the dilating drops may also cause increased pressure in the eye, leading to nausea and pain. Patients who experience serious symptoms are advised to seek medical attention immediately. Adults need no special preparation for the test; however children may need some preparation, depending on age, previous experiences, and level of trust. == Illumination == Various methods of slitlamp illumination


id: slit-lamp-20260505-2
file: data/en.wikipedia.org/wiki/Slit_lamp-2.md
category: reference
title: Slit lamp
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Slit_lamp
date_saved: 2026-05-05T09:43:35.131086+00:00
instance: kb-cron
parent: slit-lamp-20260505-0
summary:
Fundus observation is generally performed via ophthalmoscopy, where the observer (fundus camera or observing eye) is focused to infinity, which brings the subject's fundus into focus due to the refractive power of the subject's optical media. In contrast, the microscope in slit lamp biomicroscopy is focused to the anterior segments of the eye, such that direct observation of the fundus is impossible due to the subject's refractive power. However, with the use of auxiliary optics, the fundus can be brought within the focusing range of the microscope. These optics usually take the form of a lens placed on or near the subject's cornea, which range in optical properties and practical application. Watzke–Allen test is a test used in diagnosis of a full thickness macular hole and also to assess retinal function after surgical closure of the hole, with the help of slit lamp. == Light filters == Most slit-lamps have five light filters options: Unfiltered, Heat absorption- for increased patient comfort Grey filter, Red free- for better visualisation of nerve fibre layer and haemorrhages and blood vessels. Cobalt blue- after staining with fluorescein dye, for seeing corneal ulcers, contact lens fitting, Seidel's test === Cobalt blue light === Slit lamps


id: spherometer-20260505-0
file: data/en.wikipedia.org/wiki/Spherometer-0.md
category: reference
title: Spherometer
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Spherometer
date_saved: 2026-05-05T09:43:36.305316+00:00
instance: kb-cron
parent: spherometer-20260505-0
summary:
A spherometer is an instrument used for the precise measurement of the radius of curvature of a curved surface. Originally, these instruments were primarily used by opticians to measure the curvature of the surface of a lens. == Design == A spherometer usually consists of: A frame with three legs, arranged in an equilateral triangle of known radius. The outer legs of some spherometers can be moved to a set of inner holes in order to accommodate a smaller surface. The lower ends of the legs are finely tapered and terminate in hemispheres. A central leg, which can be raised or lowered via a screw. A reading device for measuring the distance the central leg is moved. Often this consists of a marked dial attached to the top of the screw and a vertical scale attached to the frame. This both indicates the number of turns of the screw and serves as an index for reading the divisions on the dial. A lens may be fitted in order to magnify the scale divisions. On new spherometers, the vertical scale is marked off in units of 0.5 mm. One complete turn of the dial also corresponds to 0.5 mm and each


id: stauroscope-20260505-0
file: data/en.wikipedia.org/wiki/Stauroscope-0.md
category: reference
title: Stauroscope
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Stauroscope
date_saved: 2026-05-05T09:43:37.484613+00:00
instance: kb-cron
parent: stauroscope-20260505-0
summary:
A stauroscope is an optical instrument used in determining the position of the planes of light-vibration in sections of crystals. The word comes from Greek for cross + scope. It was invented by Wolfgang Franz von Kobell in 1855. == References ==


id: stereoautograph-20260505-0
file: data/en.wikipedia.org/wiki/Stereoautograph-0.md
category: reference
title: Stereoautograph
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Stereoautograph
date_saved: 2026-05-05T09:43:38.646837+00:00
instance: kb-cron
parent: stereoautograph-20260505-0
summary:
The stereoautograph is a complex opto-mechanical measurement instrument for the evaluation of analog or digital photograms. It is based on the stereoscopy effect by using two aero photos or two photograms of the topography or of buildings from different standpoints. It was invented by Eduard von Orel in 1907. The photograms or photographic plates are oriented by measured passpoints in the field or on the building. This procedure can be carried out digitally (by methods of triangulation and projective geometry or iteratively (repeated angle corrections by congruent rays). The accuracy of modern autographs is about 0.001 mm. Well known are the instruments of the companies Wild Heerbrugg (Leica), e.g. analog A7, B8 of the 1980s and the digital autographs beginning in the 1990s, or special instruments of Zeiss and Contraves. == References == Gilbert Willy U.S. patent 1,477,082 Military Topography and Photography by Floyd D. Carlock, U.S. Army, 1916, p.104 ff, with photos (Available online at Google Books)


id: theodolite-20260505-0
file: data/en.wikipedia.org/wiki/Theodolite-0.md
category: reference
title: Theodolite
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Theodolite
date_saved: 2026-05-05T09:43:39.815016+00:00
instance: kb-cron
parent: theodolite-20260505-0
summary:
A theodolite () is a precision optical instrument for measuring angles between designated visible points in the horizontal and vertical planes. The traditional use has been for land surveying, but it is also used extensively for building and infrastructure construction, and some specialized applications such as meteorology and rocket launching. It consists of a moveable telescope mounted so it can rotate around horizontal and vertical axes and provide angular readouts. These indicate the orientation of the telescope, and are used to relate the first point sighted through the telescope to subsequent sightings of other points from the same theodolite position. Depending on the instrument, these angles can be measured with accuracies down to microradians or seconds of arc. From these readings a plan can be drawn, or objects can be positioned in accordance with an existing plan. The modern theodolite has evolved into what is known as a total station where angles and distances are measured electronically, and are read directly to computer memory. A transit theodolite has a telescope short enough to rotate about the instrument's horizontal trunnion axis, turning the scope through the vertical plane and its zenith; vertical rotation in non-transit instruments is restricted to a limited


id: theodolite-20260505-1
file: data/en.wikipedia.org/wiki/Theodolite-1.md
category: reference
title: Theodolite
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Theodolite
date_saved: 2026-05-05T09:43:39.815016+00:00
instance: kb-cron
parent: theodolite-20260505-0
summary:
=== Historical background === Prior to the theodolite, instruments such as the groma, geometric square and the dioptra, and various other graduated circles (see circumferentor) and semicircles (see graphometer) were used to obtain either vertical or horizontal angle measurements. Over time their functions were combined into a single instrument that could measure both angles simultaneously. The first occurrence of the word theodolite is found in the surveying textbook A geometric practice named Pantometria (1571) by Leonard Digges. The origin of the word is unknown. The first part of the Neo-Latin theo-delitus might stem from the Greek θεᾶσθαι 'to behold or look attentively upon' The second part is often attributed to an unscholarly variation of the Greek word: δῆλος 'evident' or 'clear'. Other Neo-Latin or Greek derivations have been suggested as well as an English origin from alidade. The early forerunners of the theodolite were sometimes azimuth instruments for measuring horizontal angles, while others had an altazimuth mount for measuring horizontal and vertical angles. Gregorius Reisch illustrated an altazimuth instrument in the appendix of his 1512 book Margarita Philosophica. Martin Waldseemüller, a topographer and cartographer made the device in that year calling it the polimetrum. In Digges's book of 1571, the


id: theodolite-20260505-2
file: data/en.wikipedia.org/wiki/Theodolite-2.md
category: reference
title: Theodolite
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Theodolite
date_saved: 2026-05-05T09:43:39.815016+00:00
instance: kb-cron
parent: theodolite-20260505-0
summary:
Triangulation, as invented by Gemma Frisius around 1533, consists of making direction plots of the surrounding landscape from two separate standpoints. The two graphing papers are superimposed, providing a scale model of the landscape, or rather the targets in it. The true scale can be obtained by measuring one distance both in the real terrain and in the graphical representation. Modern triangulation as, e.g., practiced by Willebrord Snellius, is the same procedure executed by numerical means. Photogrammetric block adjustment of stereo pairs of aerial photographs is a modern, three-dimensional variant. In the late 1780s, Jesse Ramsden, a Yorkshireman from Halifax, England, who had developed the dividing engine for dividing angular scales accurately to within a second of arc (≈ 0.0048 mrad or 4.8 μrad), was commissioned to build a new instrument for the British Ordnance Survey. The Ramsden theodolite was used over the next few years to map the whole of southern Britain by triangulation. In network measurement, the use of forced centering speeds up operations while maintaining the highest precision. The theodolite or the target can be rapidly removed from, or socketed into, the forced centering plate with sub-millimeter precision. Nowadays GPS antennas used for geodetic positioning use a


id: theodolite-20260505-3
file: data/en.wikipedia.org/wiki/Theodolite-3.md
category: reference
title: Theodolite
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Theodolite
date_saved: 2026-05-05T09:43:39.815016+00:00
instance: kb-cron
parent: theodolite-20260505-0
summary:
A gyrotheodolite is used when the north-south reference bearing of the meridian is required in the absence of astronomical star sights. This occurs mainly in the underground mining industry and in tunnel engineering. For example, where a conduit must pass under a river, a vertical shaft on each side of the river might be connected by a horizontal tunnel. A gyrotheodolite can be operated at the surface and then again at the foot of the shafts to identify the directions needed to tunnel between the base of the two shafts. Unlike an artificial horizon or inertial navigation system, a gyrotheodolite cannot be relocated while it is operating. It must be restarted again at each site. The gyrotheodolite comprises a normal theodolite with an attachment that contains a gyrocompass, a device which senses the rotation of the Earth in order to find true north and thus, in conjunction with the direction of gravity, the plane of the meridian. The meridian is the plane that contains both the axis of the Earth's rotation and the observer. The intersection of the meridian plane with the horizontal defines the true north-south direction found in this way. Unlike magnetic compasses, gyrocompasses are able to find


id: tiny-ionospheric-photometer-20260505-0
file: data/en.wikipedia.org/wiki/Tiny_Ionospheric_Photometer-0.md
category: reference
title: Tiny Ionospheric Photometer
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Tiny_Ionospheric_Photometer
date_saved: 2026-05-05T09:43:40.992547+00:00
instance: kb-cron
parent: tiny-ionospheric-photometer-20260505-0
summary:
The tiny ionospheric photometer (TIP) is a small space-based photometer that observes the Earth's ionosphere at 135.6 nm. The TIP instruments were designed and built by the US Naval Research Laboratory (NRL) and are a part of the COSMIC program. == Operation == Although each TIP instrument is fairly simple in design and operation, the value of this instrument is that six of them were launched at once, and they observe the Earth simultaneously from three orbital planes spaced equally apart around the Earth. The data of this instrument when combined with the data from the other COSMIC payloads allows a 3D tomographic analysis of the Earth's ionosphere to be performed. == See also == Constellation Observing System for Meteorology, Ionosphere, and Climate (COSMIC) == References == == External links == Official Website


id: total-station-20260505-0
file: data/en.wikipedia.org/wiki/Total_station-0.md
category: reference
title: Total station
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Total_station
date_saved: 2026-05-05T09:43:42.149349+00:00
instance: kb-cron
parent: total-station-20260505-0
summary:
A total station or total station theodolite is an electronic/optical instrument used for surveying and building construction. It is an electronic transit theodolite integrated with electronic distance measurement (EDM) to measure both vertical and horizontal angles and the slope distance from the instrument to a particular point, and an on-board computer to collect data and perform triangulation and position resection and intersection calculations. Robotic or motorized total stations allow the operator to control the instrument from a distance via remote control. In theory, this eliminates the need for an assistant staff member, as the operator holds the retroreflector and controls the total station from the observed point. In practice, however, an assistant surveyor is often needed when the surveying is being conducted in busy areas such as on a public carriageway or construction site. This is to prevent people from disrupting the total station as they walk past, which would necessitate resetting the tripod and re-establishing a baseline. Additionally, an assistant surveyor discourages opportunistic theft, which is not uncommon due to the value of the instrument. If all else fails, most total stations have serial numbers. In the United States the National Society of Professional Surveyors hosts a registry of


id: total-station-20260505-1
file: data/en.wikipedia.org/wiki/Total_station-1.md
category: reference
title: Total station
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Total_station
date_saved: 2026-05-05T09:43:42.149349+00:00
instance: kb-cron
parent: total-station-20260505-0
summary:
=== Mining === Total stations are the primary survey instrument used in mining surveying. A total station is used to record the absolute location of the tunnel walls, ceilings (backs), and floors, as the drifts of an underground mine are driven. The recorded data are then downloaded into a CAD program and compared to the designed layout of the tunnel. The survey party installs control stations at regular intervals. These are small steel plugs installed in pairs in holes drilled into walls or the back. For wall stations, two plugs are installed in opposite walls, forming a line perpendicular to the drift. For back stations, two plugs are installed in the back, forming a line parallel to the drift. A set of plugs can be used to locate the total station set up in a drift or tunnel by processing measurements to the plugs by intersection and resection. === Mechanical and electrical construction === Total stations have become the highest standard for most forms of construction layout. They are most often used in the X and Y axes to lay out the locations of penetrations out of the underground utilities into the foundation, between floors of a structure, as well


id: upside-down-goggles-20260505-0
file: data/en.wikipedia.org/wiki/Upside_down_goggles-0.md
category: reference
title: Upside down goggles
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Upside_down_goggles
date_saved: 2026-05-05T09:43:43.314607+00:00
instance: kb-cron
parent: upside-down-goggles-20260505-0
summary:
Upside down goggles, also known as "invertoscopes" by Russian researchers, are optical instruments that invert the image received by the retinas upside down. They are used to study human visual perception, particularly psychological process of building a visual image in the brain. Objects viewed through such a device appear upside down and mirrored. They are constructed using sets of optical right-angle prisms, concave mirrors, or a mirror plus right-angle prisms with unequal cathethus. == Purpose == Upside down goggles can be used to demonstrate human adaptation to inverted vision, and as a method of preventing motion sickness. Hubert Dolezal recommended using upside down goggles for "nausea adaptation" for space travel. They can also be used to train spatial abilities and possibly cognitive functions. == Effect == Under normal circumstances, an inverted image is formed on the retina of the eye. With the help of upside down goggles, the image on the retina of the observer's eyes is turned back (straightened) and thus the space around the observer looks upside down. == History == George M. Stratton designed the first upside down goggles for a psychological experiment. His device used short-focus lenses. Stratton used a one-tube, monocular device because this also


id: wavefront-curvature-sensor-20260505-0
file: data/en.wikipedia.org/wiki/Wavefront_curvature_sensor-0.md
category: reference
title: Wavefront curvature sensor
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Wavefront_curvature_sensor
date_saved: 2026-05-05T09:43:45.713577+00:00
instance: kb-cron
parent: wavefront-curvature-sensor-20260505-0
summary:
A wavefront curvature sensor is a device for measuring the aberrations of an optical wavefront. Like a Shack–Hartmann wavefront sensor it uses an array of small lenses (or lenslets) to focus the wavefront into an array of spots. Unlike the Shack-Hartmann, which measures the position of the spots, the curvature sensor measures the intensity on either side of the focal plane. If a wavefront has a phase curvature, it will alter the position of the focal spot along the axis of the beam, thus by measuring the relative intensities in two places the curvature can be deduced. == See also == Adaptive optics Wavefront sensor == Sources == Roddier, François (1988). "Curvature sensing and compensation: a new concept in adaptive optics". Applied Optics. 27 (7): 1223–1225. Bibcode:1988ApOpt..27.1223R. doi:10.1364/AO.27.001223. PMID 20531543. Roddier, François; Roddier, Claude (March 1988). Ulrich, M. H. (ed.). "Curvature Sensing and Compensation: A New Concept in Adaptive Optics". Very Large Telescopes and Their Instrumentation. European Southern Observatory Conference and Workshop Proceedings. 30 (7): 1223–5. Bibcode:1988ESOC...30..667R. doi:10.1364/AO.27.001223. PMID 20531543.


id: accelerograph-20260505-0
file: data/en.wikipedia.org/wiki/Accelerograph-0.md
category: reference
title: Accelerograph
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Accelerograph
date_saved: 2026-05-05T09:43:48.291339+00:00
instance: kb-cron
parent: accelerograph-20260505-0
summary:
An accelerograph can be referred to as a strong-motion instrument or seismograph, or simply an earthquake accelerometer. They are usually constructed as a self-contained box, which previously included a paper or film recorder (an analogue instrument) but now they often record directly on digital media and then the data is transmitted via the Internet. Accelerographs are useful for when the earthquake ground motion is so strong that it causes the more sensitive seismometers to go off-scale. There is an entire science of strong ground motion, that is dedicated to studying the shaking in the vicinity of earthquakes (roughly within about 100 km of the fault rupture). Accelerographs record the acceleration of the ground with respect to time. This recording is often called an accelerograms, strong-motion record or acceleration time-history. From this record strong-motion intensity measures (IMs, also called parameters) can be computed. The simplest of which is peak ground acceleration (PGA). Other IMs include Arias intensity, peak ground velocity (PGV), for which the accelerogram needs to be integrated once, peak ground displacement (PGD), for which double integration is required. Often a response spectrum is computed to show how the earthquake would affect structures of different natural frequencies or periods. These


id: coconet-20260505-0
file: data/en.wikipedia.org/wiki/COCONet-0.md
category: reference
title: COCONet
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/COCONet
date_saved: 2026-05-05T09:43:49.481321+00:00
instance: kb-cron
parent: coconet-20260505-0
summary:
Continuously Operating Caribbean GPS Observational Network (COCONet) was a global positioning system (GPS) observation network that spanned across the Caribbean and the neighboring area It was part of UNAVCO (University Navstar Corporation). UNAVCO and IRIS (Incorporated Research Institutions for Seismology) Consortium later merged to create EarthScope Consortium in 2023. The project was initiated after the devastation of the 2010 Haiti Earthquake, which was a 7.0 Mw earthquake. Starting from 2011, UNAVCO built and operated COCONet for the National Science Foundation (NSF). It was a network of continuous GPS meteorology or cGPS/Met sites. Along with the NSF-funded TLALOCNet GPS network in Mexico, the two networks of cGPS-Met instrumentation were available to support research in Mexico, Central America, and the Caribbean. == Function == The purpose of COCOnet was to: Provide details on the tectonics of the entire Caribbean region. Enhance atmospheric observations that can be used for testing and validation of climate and weather models. Improve the analysis of local geodetic (the science of planetary measurement) measurements by providing access to an integrated backbone electronic network of reference stations. Increase our ability to model and predict the natural hazards (earthquakes, hurricanes and so on) in the region. To accomplish the function


id: galperin-configuration-20260505-0
file: data/en.wikipedia.org/wiki/Galperin_configuration-0.md
category: reference
title: Galperin configuration
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Galperin_configuration
date_saved: 2026-05-05T09:43:50.630864+00:00
instance: kb-cron
parent: galperin-configuration-20260505-0
summary:
Galperin configuration are a particular configuration of sensing elements found in a class of seismic instruments measuring ground motion and are named after Soviet seisomologist Evsey Iosifovich Galperin, who introduced it in 1955 for petroleum exploration. == Description == Common triaxial seismometers provide signal outputs in three orthogonal axes oriented towards east–west (E), north–south (N) and up-down (Z), i.e. in the Cartesian coordinate system. In contrast, the Galperin configuration consists of three orthogonal axes (U, V, W) that are oriented at precisely the same angle with respect to the horizontal plane (α=35.26°). The projection of all three axes onto the horizontal plane are all separated by 120°, which results in the "symmetric triaxial" design. The recordings acquired with the Galperin configuration are brought to the Cartesian coordinate system by the following coordinate transformation, where β=30°: [ E N Z ] = [ − cos ⁡ α cos ⁡ α sin ⁡ β cos ⁡ α sin ⁡ β 0 cos ⁡ α cos ⁡ β − cos ⁡ α cos ⁡ β sin ⁡ α sin ⁡ α sin ⁡ α ] [ U V W ] {\displaystyle {\begin{bmatrix}E\\N\\Z\end{bmatrix}}={\begin{bmatrix}-\cos \alpha &\cos \alpha \sin \beta &\cos \alpha \sin \beta \\0&\cos \alpha


id: geophone-20260505-0
file: data/en.wikipedia.org/wiki/Geophone-0.md
category: reference
title: Geophone
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Geophone
date_saved: 2026-05-05T09:43:51.799682+00:00
instance: kb-cron
parent: geophone-20260505-0
summary:
A geophone is a device that converts ground movement (velocity) into voltage, which may be recorded at a recording station. The deviation of this measured voltage from the base line is called the seismic response and is analyzed for structure of the Earth. == Etymology == The term geophone derives from the Greek word "γῆ (ge) " meaning "earth" and "phone" meaning "sound". == Construction == Geophones have historically been passive analog devices and typically comprise a spring-mounted wire coil moving within the field of a case-mounted permanent magnet to generate an electrical signal. Recent designs have been based on microelectromechanical systems (MEMS) technology which generates an electrical response to ground motion through an active feedback circuit to maintain the position of a small piece of silicon. The response of a coil/magnet geophone is proportional to ground velocity, while MEMS devices usually respond proportional to acceleration. MEMS have a much higher noise level (50 dB velocity higher) than geophones and can only be used in strong motion or active seismic applications. == Frequency response == The frequency response of a geophone is that of a harmonic oscillator, fully determined by corner frequency (typically around 10 Hz) and damping (typically 0.707).


id: mermaid-20260505-0
file: data/en.wikipedia.org/wiki/MERMAID-0.md
category: reference
title: MERMAID
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/MERMAID
date_saved: 2026-05-05T09:43:53.042340+00:00
instance: kb-cron
parent: mermaid-20260505-0
summary:
MERMAID is a marine scientific instrument platform, short for Mobile Earthquake Recorder for Marine Areas by Independent Divers. MERMAID evolved from a first prototype, developed and built by Scripps Institution of Oceanography in partnership with Princeton University, to a second, built by Teledyne Webb Research in collaboration with the University of Nice Sophia Antipolis, and now third-generation model, operational today, commercialized by OSEAN SAS in Le Pradet, France. Fourth-generation models add hydrographic monitoring capability to complement the acoustic sensor suite, and are designed to carry out measurement profiles to depths exceeding 4,000 m. MERMAID is a freely-drifting float equipped with a hydrophone to collect hydroacoustic data for the study of earthquakes worldwide. Typically floating at a parking depth of 1500 m, the instrument uses a buoyancy engine (a hydraulic oil bladder system) to return to the surface for triggered data transmission (on average every 6–7 days) via the Iridium satellite constellation, to respond to on-demand data requests, and to receive mission parameter updates. MERMAID carries lithium-ion batteries, sufficient to power about 250 descend/ascend cycles, which translates to an instrument autonomy of about 5 years. A pressure sensor monitors descent depth, and a GPS receiver provides location and time corrections during


id: ocean-bottom-seismometer-20260505-0
file: data/en.wikipedia.org/wiki/Ocean-bottom_seismometer-0.md
category: reference
title: Ocean-bottom seismometer
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Ocean-bottom_seismometer
date_saved: 2026-05-05T09:43:54.235687+00:00
instance: kb-cron
parent: ocean-bottom-seismometer-20260505-0
summary:
An ocean-bottom seismometer (OBS) is a seismometer that is designed to record the earth's motion under oceans and lakes from man-made sources and natural sources. Sensors at the sea floor are used to observe acoustic and seismic events. Seismic and acoustic signals may be caused by different sources, by earthquakes and tremors as well as by artificial sources. Computing and analyzing the data yields information about the kind of source and, in case of natural seismic events, the geophysics and geology of the sea floor and the deeper crust. The deployment of OBS along a profile will give information about the deep structure of the Earth's crust and upper mantle in offshore areas. OBS may be equipped with a maximum of a three-component geophone in addition to a hydrophone, and thus it needs a capacity of more than 144 Mbytes, which would be the minimum for adequate MCS profiling. In a typical survey, the instruments should be operational for several days (deployments can exceed 12 months), which requires a data storage capacity of more than 500 Mbyte. Other experiments, such as tomographic investigations within a 3D-survey or seismological monitoring, demand even larger capacities. == Instrument package == The OBS consists


id: ocean-bottom-seismometer-20260505-1
file: data/en.wikipedia.org/wiki/Ocean-bottom_seismometer-1.md
category: reference
title: Ocean-bottom seismometer
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Ocean-bottom_seismometer
date_saved: 2026-05-05T09:43:54.235687+00:00
instance: kb-cron
parent: ocean-bottom-seismometer-20260505-0
summary:
== Disadvantages == The environment of these deployments complicates standard methods that are used in analyzing the data because of the ocean on top of the seismometer, as opposed to free-air above a typical land station. These seismometers also have a decreased signal-to-noise ratio because of noise created by the movement of the oceans due to wind driven tides, particularly at periods of 7 and 14 seconds. This long period motion and current flowing around the seismometer can create problems of long period noise on the horizontal components because the soft (saturated) sediment that the seismometer is resting on is more susceptible to allow the seismometer to tilt and ideally, the horizontal component will not move and be perpendicular to gravity to get the best results out of the seismometer. The saturated sediment also reduces signal-to-noise ratio significantly because the velocity of the P and S waves decreases and the seismic waves get trapped in the sediment layer creating a large amplitude ringing due to the conservation of energy. == Notable deployments == One of the largest OBS deployments ever was The Big Mantle Electromagnetic and Tomography (Big MELT) Experiment, involving almost 100 OBS in the East Pacific Rise with


id: seismic-array-20260505-0
file: data/en.wikipedia.org/wiki/Seismic_array-0.md
category: reference
title: Seismic array
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Seismic_array
date_saved: 2026-05-05T09:43:55.448067+00:00
instance: kb-cron
parent: seismic-array-20260505-0
summary:
A seismic array is a system of linked seismometers arranged in a regular geometric pattern (cross, circle, rectangular etc.) to increase sensitivity to earthquake and explosion detection. A seismic array differs from a local network of seismic stations mainly by the techniques used for data analysis. The data from a seismic array is obtained using special digital signal processing techniques such as beamforming, which suppress noises and thus enhance the signal-to-noise ratio (SNR). The earliest seismic arrays were built in the 1950s in order to improve the detection of nuclear tests worldwide. Many of these deployed arrays were classified until the 1990s. Today they have become part of the International Monitoring System (IMS) as primary or auxiliary stations. Seismic arrays are not only used to monitor earthquakes and nuclear tests but also used as a tool for investigating nature and source regions of microseisms as well as locating and tracking volcanic tremor and analyzing complex seismic wave-field properties in volcanic areas. == Layout == Seismic arrays can be classified by size, which is defined by the array's aperture given by the largest distance between the single seismometers. The sensors in a seismic array are arranged in different geometric patterns horizontally.


id: seismic-array-20260505-1
file: data/en.wikipedia.org/wiki/Seismic_array-1.md
category: reference
title: Seismic array
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Seismic_array
date_saved: 2026-05-05T09:43:55.448067+00:00
instance: kb-cron
parent: seismic-array-20260505-0
summary:
Assuming that the noise nj(t) has a normal amplitude distribution with zero mean and variance σ2 at all sites, then the variance of the noise after summation is σ s 2 = M σ 2 {\displaystyle \sigma _{s}^{2}=M\sigma ^{2}} and the standard deviation is M σ 2 {\displaystyle {\sqrt {M}}\sigma ^{2}} . That means the standard deviation of the noise is multiplied by M {\displaystyle {\sqrt {M}}} while the coherent signal is multiplied by M {\displaystyle M} . The theoretical improvement of the SNR by beamforming (aka array gain) will be G = M {\displaystyle G={\sqrt {M}}} for an array containing M sites. ==== The N-th root process ==== N-th root process is a non-linear method to enhance the SNR during beamforming. Before summing up the single seismic traces, the N-th root is calculated for each trace retaining the sign information. signum{wj(t)} is a function defined as -1 or +1, depending on the sign of the actual sample wj(t). N is an integer that has to be chosen by the analyst B N ( t ) = ∑ j = 1 M n j ( t + τ j ) N ⋅ s i g n u m { w


id: seismic-array-20260505-2
file: data/en.wikipedia.org/wiki/Seismic_array-2.md
category: reference
title: Seismic array
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Seismic_array
date_saved: 2026-05-05T09:43:55.448067+00:00
instance: kb-cron
parent: seismic-array-20260505-0
summary:
E ( ω , k 0 − k ) = 1 2 π ∫ − ∞ ∞ | w ¯ ( ω ) | 2 ⋅ | C ( k 0 − k ) | 2 d ω {\displaystyle E(\omega ,k_{0}-k)={\frac {1}{2\pi }}\int _{-\infty }^{\infty }|{\bar {w}}(\omega )|^{2}\cdot |C(k_{0}-k)|^{2}d\omega } , where C ( k 0 − k ) = 1 M ∑ j = 1 M e i w r j ( k 0 − k ) {\displaystyle C(k_{0}-k)={\frac {1}{M}}\sum _{j=1}^{M}e^{iwr_{j}(k_{0}-k)}} This equation is called the transfer function of an array. If the slowness difference is zero, the factor | C ( k 0 − k ) | 2 {\displaystyle |C(k_{0}-k)|^{2}} becomes 1.0 and the array is optimally tuned for this slowness. All other energy propagating with a different slowness will be suppressed. === Slowness estimation === Slowness estimation is a matter of forming beams with different slowness vectors and comparing the amplitudes or the power of the beams, and finding out the best beam by looking for the vapp and backazimuth combination with the highest energy on the beam. ==== f-k analysis ==== Frequency-wavenumber analysis is used as a reference tool in array processing for estimating slowness. This


id: seismometer-20260505-0
file: data/en.wikipedia.org/wiki/Seismometer-0.md
category: reference
title: Seismometer
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Seismometer
date_saved: 2026-05-05T09:43:56.624148+00:00
instance: kb-cron
parent: seismometer-20260505-0
summary:
A seismometer is an instrument that responds to ground displacement and shaking caused by quakes, volcanic eruptions, and explosions. They are usually combined with a timing device and a recording device to form a seismograph. The output of such a device—formerly recorded on paper (see picture) or film, now recorded and processed digitally—is a seismogram. Such data is used to locate and characterize earthquakes, and to study the internal structure of Earth. == Basic principles == A simple seismometer, sensitive to up-down motions of the Earth, is like a weight hanging from a spring, both suspended from a frame that moves along with any motion detected. The relative motion between the weight (called the mass) and the frame provides a measurement of the vertical ground motion. A rotating drum is attached to the frame and a pen is attached to the weight, thus recording any ground motion in a seismogram. Any movement from the ground moves the frame. The mass tends not to move because of its inertia, and by measuring the movement between the frame and the mass, the motion of the ground can be determined. Early seismometers used optical levers or mechanical linkages to amplify the small motions


id: seismometer-20260505-1
file: data/en.wikipedia.org/wiki/Seismometer-1.md
category: reference
title: Seismometer
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Seismometer
date_saved: 2026-05-05T09:43:56.624148+00:00
instance: kb-cron
parent: seismometer-20260505-0
summary:
Some secondary sources mention unverified claims that a device resembling an earthquake detector may have existed in Ancient Egypt, but as of January 2026, no reliable historical sources confirm this, and the earliest well-documented seismoscope was invented in China by Zhang Heng in AD 132. In AD 132, Zhang Heng of China's Han dynasty is said to have invented the first seismoscope (by the definition above), which was called Houfeng Didong Yi (translated as, "instrument for measuring the seasonal winds and the movements of the Earth"). The description we have, from the History of the Later Han Dynasty, says that it was a large bronze vessel, about 2 meters in diameter; at eight points around the top were dragon's heads holding bronze balls. When there was an earthquake, one of the dragons' mouths would open and drop its ball into a bronze toad at the base, making a sound and supposedly showing the direction of the earthquake. On at least one occasion, probably at the time of a large earthquake in Gansu in AD 143, the seismoscope indicated an earthquake even though one was not felt. The available text says that inside the vessel was a central column that could


id: seismometer-20260505-2
file: data/en.wikipedia.org/wiki/Seismometer-2.md
category: reference
title: Seismometer
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Seismometer
date_saved: 2026-05-05T09:43:56.624148+00:00
instance: kb-cron
parent: seismometer-20260505-0
summary:
=== Early Modern designs (1839–1880) === In response to a series of earthquakes near Comrie in Scotland in 1839, a committee was formed in the United Kingdom in order to produce better detection devices for earthquakes. The outcome of this was an inverted pendulum seismometer constructed by James David Forbes, first presented in a report by David Milne-Home in 1842, which recorded the measurements of seismic activity through the use of a pencil placed on paper above the pendulum. The designs provided did not prove effective, according to Milne's reports. It was Milne who coined the word seismometer in 1841, to describe this instrument. In 1843, the first horizontal pendulum was used in a seismometer, reported by Milne (though it is unclear if he was the original inventor). After these inventions, Robert Mallet published an 1848 paper where he suggested ideas for seismometer design, suggesting that such a device would need to register time, record amplitudes horizontally and vertically, and ascertain direction. His suggested design was funded, and construction was attempted, but his final design did not fulfill his expectations and suffered from the same problems as the Forbes design, being inaccurate and not self-recording. Karl Kreil constructed a seismometer


id: seismometer-20260505-3
file: data/en.wikipedia.org/wiki/Seismometer-3.md
category: reference
title: Seismometer
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Seismometer
date_saved: 2026-05-05T09:43:56.624148+00:00
instance: kb-cron
parent: seismometer-20260505-0
summary:
In 1880, the first horizontal pendulum seismometer was developed by the team of John Milne, James Alfred Ewing and Thomas Gray, who worked as foreign-government advisors in Japan, from 1880 to 1895. Milne, Ewing and Gray, all having been hired by the Meiji Government in the previous five years to assist Japan's modernization efforts, founded the Seismological Society of Japan in response to an Earthquake that took place on February 22, 1880, at Yokohama (Yokohama earthquake). Two instruments were constructed by Ewing over the next year, one being a common-pendulum seismometer and the other being the first seismometer using a damped horizontal pendulum. The innovative recording system allowed for a continuous record, the first to do so. The first seismogram was recorded on 3 November 1880 on both of Ewing's instruments. Modern seismometers would eventually descend from these designs. Milne has been referred to as the 'Father of modern seismology' and his seismograph design has been called the first modern seismometer. This produced the first effective measurement of horizontal motion. Gray would produce the first reliable method for recording vertical motion, which produced the first effective 3-axis recordings. An early special-purpose seismometer consisted of a large, stationary pendulum, with a


id: seismometer-20260505-4
file: data/en.wikipedia.org/wiki/Seismometer-4.md
category: reference
title: Seismometer
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Seismometer
date_saved: 2026-05-05T09:43:56.624148+00:00
instance: kb-cron
parent: seismometer-20260505-0
summary:
Modern instruments use electronic sensors, amplifiers, and recording devices. Most are broadband covering a wide range of frequencies. Some seismometers can measure motions with frequencies from 500 Hz to 0.00118 Hz (1/500 = 0.002 seconds per cycle, to 1/0.00118 = 850 seconds per cycle). The mechanical suspension for horizontal instruments remains the garden-gate described above. Vertical instruments use some kind of constant-force suspension, such as the LaCoste suspension. The LaCoste suspension uses a zero-length spring to provide a long period (high sensitivity). Some modern instruments use a "triaxial" or "Galperin" design, in which three identical motion sensors are set at the same angle to the vertical but 120 degrees apart on the horizontal. Vertical and horizontal motions can be computed from the outputs of the three sensors. Seismometers unavoidably introduce some distortion into the signals they measure, but professionally designed systems have carefully characterized frequency transforms. Modern sensitivities come in three broad ranges: geophones, 50 to 750 V/m; local geologic seismographs, about 1,500 V/m; and teleseismographs, used for world survey, about 20,000 V/m. Instruments come in three main varieties: short-period, long-period and broadband. The short- and long-period instruments measure velocity and are very sensitive; however they 'clip' the signal or


id: seismometer-20260505-5
file: data/en.wikipedia.org/wiki/Seismometer-5.md
category: reference
title: Seismometer
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Seismometer
date_saved: 2026-05-05T09:43:56.624148+00:00
instance: kb-cron
parent: seismometer-20260505-0
summary:
=== Interconnected seismometers === Seismometers spaced in a seismic array can also be used to precisely locate, in three dimensions, the source of an earthquake, using the time it takes for seismic waves to propagate away from the hypocenter, the initiating point of fault rupture (See also Earthquake location). Interconnected seismometers are also used, as part of the International Monitoring System to detect underground nuclear test explosions, as well as for Earthquake early warning systems. These seismometers are often used as part of a large-scale governmental or scientific project, but some organizations such as the Quake-Catcher Network, can use residential size detectors built into computers to detect earthquakes as well. In reflection seismology, an array of seismometers image sub-surface features. The data are reduced to images using algorithms similar to tomography. The data reduction methods resemble those of computer-aided tomographic medical imaging X-ray machines (CAT-scans), or imaging sonars. A worldwide array of seismometers can actually image the interior of the Earth in wave-speed and transmissivity. This type of system uses events such as earthquakes, impact events or nuclear explosions as wave sources. The first efforts at this method used manual data reduction from paper seismograph charts. Modern digital seismograph records


id: strainmeter-20260505-0
file: data/en.wikipedia.org/wiki/Strainmeter-0.md
category: reference
title: Strainmeter
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Strainmeter
date_saved: 2026-05-05T09:43:57.834911+00:00
instance: kb-cron
parent: strainmeter-20260505-0
summary:
A strainmeter is an instrument used by geophysicists to measure the deformation of the Earth. Linear strainmeters measure the changes in the distance between two points, using either a solid piece of material (over a short distance) or a laser interferometer (over a long distance, up to several hundred meters). The type using a solid length standard was invented by Benioff in 1932, using an iron pipe; later instruments used rods made of fused quartz. Modern instruments of this type can make measurements of length changes over very small distances, and are commonly placed in boreholes to measure small changes in the diameter of the borehole. Another type of borehole instrument detects changes in a volume filled with fluid (such as silicone oil). The most common type is the dilatometer invented by Sacks and Evertson in the USA (patent 3,635,076); a design that uses specially shaped volumes to measure the strain tensor has been developed by Sakata in Japan. All these types of strainmeters can measure deformation over frequencies from a few Hz to periods of days, months, and years. This allows them to measure signals at lower frequencies than can be detected with seismometers. Most strainmeter records show signals


id: tiltmeter-20260505-0
file: data/en.wikipedia.org/wiki/Tiltmeter-0.md
category: reference
title: Tiltmeter
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Tiltmeter
date_saved: 2026-05-05T09:43:59.000611+00:00
instance: kb-cron
parent: tiltmeter-20260505-0
summary:
A tiltmeter is a sensitive inclinometer designed to measure very small changes from the vertical level, either on the ground or in structures. Tiltmeters are used extensively for monitoring volcanoes, the response of dams to filling, the small movements of potential landslides, the orientation and volume of hydraulic fractures, and the response of structures to various influences such as loading and foundation settlement. Tiltmeters may be purely mechanical or incorporate vibrating-wire or electrolytic sensors for electronic measurement. A sensitive instrument can detect changes of as little as one arc second. Tiltmeters have a long, diverse history, somewhat parallel to the history of the seismometer. The very first tiltmeter was a long-length stationary pendulum. These were used in the very first large concrete dams, and are still in use today, augmented with newer technology such as laser reflectors. Although they had been used for other applications such as volcano monitoring, they have distinct disadvantages, such as their huge length and sensitivity to air currents. Even in dams, they are slowly being replaced by the modern electronic tiltmeter. Volcano and Earth movement monitoring then used the water-tube, long baseline tiltmeter. In 1919, the physicist, Albert A. Michelson, noted that the most favorable


id: wood-anderson-seismometer-20260505-0
file: data/en.wikipedia.org/wiki/Wood–Anderson_seismometer-0.md
category: reference
title: Wood–Anderson seismometer
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Wood–Anderson_seismometer
date_saved: 2026-05-05T09:44:00.145932+00:00
instance: kb-cron
parent: wood-anderson-seismometer-20260505-0
summary:
The Wood–Anderson seismometer (also known as the Wood–Anderson seismograph) is a torsion seismometer developed in the United States by Harry O. Wood and John August Anderson in the 1920s to record local earthquakes in southern California. It photographically records the horizontal motion. The seismometer uses a pendulum of 0.8g, its period is 0.8 seconds, its magnification is 2,800 times, and its damping constant is 0.8. Charles Francis Richter developed the Richter magnitude scale using the Wood–Anderson seismometer. == Overview == In 1908, geologist Grove K. Gilbert paid Harry Wood $1,000 to draft a map of potentially active faults in northern California and several years later Andrew Lawson, professor at the University of California, Berkeley assigned Wood to oversee the University's seismometers, where attention was focused on local earthquakes as well as the distant events that were used (especially by European scientists like Beno Gutenberg) to study the attributes of the Earth's interior. Seismometers that were in use up until that time had been developed and optimized for detecting the long-period seismic waves from distant earthquakes and did not detect local events well. Wood left Berkeley in 1912 and spent several years researching volcano seismology in Hawaii and made contact with


id: adron-rm-20260505-0
file: data/en.wikipedia.org/wiki/ADRON-RM-0.md
category: reference
title: ADRON-RM
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/ADRON-RM
date_saved: 2026-05-05T09:44:02.707682+00:00
instance: kb-cron
parent: adron-rm-20260505-0
summary:
ADRON-RM (Autonomous Detector of Radiation of Neutrons Onboard Rover at Mars) is a neutron spectrometer to search for subsurface water ice and hydrated minerals. This analyser is part of the science payload on board the European Space Agency's Rosalind Franklin rover, tasked to search for biosignatures and biomarkers on Mars. The rover is planned to be launched not earlier than 2028 and land on Mars in 2029. ADRON-RM is a near copy of ADRO-EM on the stationary ExoMars 2020 surface platform and the Dynamic Albedo of Neutrons (DAN) neutron detector on board NASA's Curiosity rover, all designed by Igor Mitrofanov from the Russian Space Research Institute (IKI). == Overview == ADRON-RM is a neutron spectrometer that will search for hydrogen in the form of bound water or water ice, and hydrogen-bearing compounds. It will be used in combination with WISDOM instrument (a ground-penetrating radar) to study the subsurface beneath the rover and to search for optimal sites for drilling and sample collection. It can also detect trace elements such as Gd and major elements that constitute soil, such as Cl, Fe, Ti. It will also monitor the neutron component of the radiation background on Mars' surface. == Development == The


id: advanced-technology-microwave-sounder-20260505-0
file: data/en.wikipedia.org/wiki/Advanced_Technology_Microwave_Sounder-0.md
category: reference
title: Advanced Technology Microwave Sounder
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Advanced_Technology_Microwave_Sounder
date_saved: 2026-05-05T09:44:04.496319+00:00
instance: kb-cron
parent: advanced-technology-microwave-sounder-20260505-0
summary:
The Advanced Technology Microwave Sounder (ATMS) is a 22-channel scanning microwave radiometer for observation of the Earth's atmosphere and surface. It is the successor to the Advanced Microwave Sounding Unit (AMSU) on NOAA weather satellites. ATMS units have been flown on the Suomi NPP and on the Joint Polar Satellite System. == Applications == ATMS measurements are assimilated into numerical weather prediction models and atmospheric profiles retrieved by the combination of ATMS and the Cross-track Infrared Sounder on the same satellites are useful for synoptic scale meteorology. Also, ATMS continues the record from its predecessor instruments MSU and AMSU of measurements in the 5-mm band of oxygen for monitoring of atmospheric temperature trends. == Instrument characteristics == All of the channels are contained within one unit, unlike the AMSU which comprises two instruments (AMSU-A and AMSU-B). The radiometer's antenna scans underneath the satellite through nadir, and its polarization vector rotates with the scan angle. The sampling rate satisfies the Nyquist criterion for channels 1-16; thus, images produced from the data are not aliased. However, ATMS images exhibit striping, attributed to receiver gain fluctuations (1/f noise), which can be removed by filtering the data. Table 1 lists some characteristics of the


id: advanced-very-high-resolution-radiometer-20260505-0
file: data/en.wikipedia.org/wiki/Advanced_Very-High-Resolution_Radiometer-0.md
category: reference
title: Advanced Very-High-Resolution Radiometer
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Advanced_Very-High-Resolution_Radiometer
date_saved: 2026-05-05T09:44:05.717614+00:00
instance: kb-cron
parent: advanced-very-high-resolution-radiometer-20260505-0
summary:
The Advanced Very-High-Resolution Radiometer (AVHRR) instrument is a space-borne sensor that measures the reflectance of the Earth in five spectral bands that are relatively wide by today's standards. AVHRR instruments are or have been carried by the National Oceanic and Atmospheric Administration (NOAA) family of polar orbiting platforms (POES) and European MetOp satellites. The instrument scans several channels; two are centered on the red (0.6 micrometres) and near-infrared (0.9 micrometres) regions, a third one is located around 3.5 micrometres, and another two the thermal radiation emitted by the planet, around 11 and 12 micrometres. The first AVHRR instrument was a four-channel radiometer. The final version, AVHRR/3, first carried on NOAA-15 launched in May 1998, acquires data in six channels. The AVHRR has been succeeded by the Visible Infrared Imaging Radiometer Suite, carried on the Joint Polar Satellite System spacecraft. == Operation == Prior to 2025, NOAA had at least two polar-orbiting meteorological satellites in orbit at all times, with one satellite crossing the equator in the early morning and early evening and the other crossing the equator in the afternoon and late evening. The primary sensor on board both satellites was the AVHRR instrument. Morning-satellite data were most commonly used


id: advanced-very-high-resolution-radiometer-20260505-1
file: data/en.wikipedia.org/wiki/Advanced_Very-High-Resolution_Radiometer-1.md
category: reference
title: Advanced Very-High-Resolution Radiometer
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Advanced_Very-High-Resolution_Radiometer
date_saved: 2026-05-05T09:44:05.717614+00:00
instance: kb-cron
parent: advanced-very-high-resolution-radiometer-20260505-0
summary:
==== Loeb ==== In another similar method using surface targets, Loeb [1997] uses spatiotemporal uniform ice surfaces in Greenland and Antarctica to produce second-order polynomial reflectance calibration curves as a function of solar zenith angle; calibrated NOAA-9 near-nadir reflectances are used to generate the curves that can then derive the calibrations for other AHVRRs in orbit (e.g. NOAA-11, -12, and -14). It was found that the ratio of calibration coefficients derived by Loeb [1997] and Rao and Chen [1995] are independent of solar zenith angle, thus implying that the NOAA-9-derived calibration curves provide an accurate relation between the solar zenith angle and observed reflectance over Greenland and Antarctica. ==== Iwabuchi ==== Iwabuchi [2003] employed a method to calibrate NOAA-11 and -14 that uses clear-sky ocean and stratus cloud reflectance observations in a region of the NW Pacific Ocean and radiative transfer calculations of a theoretical molecular atmosphere to calibrate AVHRR Ch. 1. Using a month of clear-sky observations over the ocean, an initial minimum guess to the calibration slope is made. An iterative method is then used to achieve the optimal slope values for Ch. 1 with slope corrections adjusting for uncertainties in ocean reflectance, water vapor, ozone, and noise.


id: advanced-very-high-resolution-radiometer-20260505-2
file: data/en.wikipedia.org/wiki/Advanced_Very-High-Resolution_Radiometer-2.md
category: reference
title: Advanced Very-High-Resolution Radiometer
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Advanced_Very-High-Resolution_Radiometer
date_saved: 2026-05-05T09:44:05.717614+00:00
instance: kb-cron
parent: advanced-very-high-resolution-radiometer-20260505-0
summary:
==== Calibration using the moderate-resolution imaging spectroradiometer ==== Another recent method for the absolute calibration of the AHVRR record makes use of the contemporary MODIS sensor onboard NASA's TERRA and AQUA satellites. The MODIS instrument has high calibration accuracy and can track its own radiometric changes due to the inclusion of an onboard calibration system for the VIS/NIR spectral region [MCST]. The following method utilizes the high accuracy of MODIS to absolutely calibrate AVHRRs via simultaneous nadir overpasses (SNOs) of both MODIS/AVHRR and AVHRR/AVHRR satellite pairs as well as MODIS-characterized surface reflectances for a Libyan Desert target and Dome-C in Antarctica [Heidinger et al., 2010]. Ultimately, each individual calibration event available (MODIS/AVHRR SNO, Dome C, Libyan Desert, or AVHRR/AVHRR SNO) is used to provide a calibration slope time series for a given AVHRR sensor. Heidinger et al. [2010] use a second-order polynomial from a least-squares fit to determine the time series. The first step involves using a radiative transfer model that will convert observed MODIS scenes into those that a perfectly calibrated AVHRR would see. For MODIS/AVHRR SNO occurrences, it was determined that the ratio of AVHRR to MODIS radiances in both Ch1 and Ch2 are modeled well by a


id: advanced-very-high-resolution-radiometer-20260505-3
file: data/en.wikipedia.org/wiki/Advanced_Very-High-Resolution_Radiometer-3.md
category: reference
title: Advanced Very-High-Resolution Radiometer
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Advanced_Very-High-Resolution_Radiometer
date_saved: 2026-05-05T09:44:05.717614+00:00
instance: kb-cron
parent: advanced-very-high-resolution-radiometer-20260505-0
summary:
== Further reading == Frey, C.; Kuenzer, C.; Dech, S. (2012). "Quantitative comparison of the operational NOAA AVHRR LST product of DLR and the MODIS LST product V005". International Journal of Remote Sensing. 33 (22): 7165–7183. Bibcode:2012IJRS...33.7165F. doi:10.1080/01431161.2012.699693. S2CID 128981116. Brest, C.L. and W.B. Rossow. 1992. Radiometric calibration and monitoring of NOAA AVHRR data for ISCCP. International Journal of Remote Sensing. Vol. 13. pp. 235–273. Brest, C.L. et al. 1997. Update of Radiance Calibrations for ISCCP. Journal of Atmospheric and Oceanic Technology. Vol 14. pp. 1091–1109. Cao, C. et al. 2008. Assessing the consistency of AVHRR and MODIS L1B reflectance for generating Fundamental Climate Data Records. Journal of Geophysical Research. Vol. 113. D09114. doi:10.1029/2007JD009363. Halthore, R. et al. 2008. Role of Aerosol Absorption in Satellite Sensor Calibration. IEEE Geoscience and Remote Sensing Letters. Vol. 5. pp. 157–161. Heidinger, A. K. et al. 2002. Using Moderate Resolution Imaging Spectrometer (MODIS) to calibrate Advanced Very High Resolution Radiometer reflectance channels. Journal of Geophysical Research. Vol. 107. doi:10.1029/2001JD002035. Heidinger, A.K. et al. 2010. Deriving an inter-sensor consistent calibration for the AVHRR solar reflectance data record. International Journal of Remote Sensing. Vol. 31. pp. 6493–6517. Iwabuchi, H. 2003. Calibration of the visible and near-infrared


id: alice-spacecraft-instrument-20260505-0
file: data/en.wikipedia.org/wiki/Alice_(spacecraft_instrument)-0.md
category: reference
title: Alice (spacecraft instrument)
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Alice_(spacecraft_instrument)
date_saved: 2026-05-05T09:44:06.912554+00:00
instance: kb-cron
parent: alice-spacecraft-instrument-20260505-0
summary:
Alice is any one of two ultraviolet imaging spectrometers; one used on the New Horizons spacecraft and the other used on the Rosetta spacecraft. Alice is a small telescope with a spectrograph and a special detector with 32 pixels each with 1024 spectral channels detecting ultraviolet light. Its primary role is to determine the relative concentrations of various elements and isotopes in Pluto's atmosphere. Alice has an off-axis telescope which sends light to a Rowland-circle spectrograph, and the instrument has a field of view of 6 degrees. It is designed to capture airglow and solar occultation at the same time, and has two inputs to allow this. == Overview == Alice uses an array of potassium bromide and caesium iodide type of photocathodes. It detects in the extreme and far ultraviolet spectrum, from 700–2,050 Å (70–205 nm) wavelengths of light, with a spectral resolution of 8–12 Å (0.80–1.20 nm) and a spatial resolution of 500 metres (1,600 feet) per 50 km (31 miles) of altitude. Alice is intended, among its capabilities, to detect ultraviolet signatures of noble (aka inert) gases including helium, neon, argon, and krypton. Alice should also be able to detect water, carbon monoxide, and carbon dioxide in


id: alpha-particle-x-ray-spectrometer-20260505-0
file: data/en.wikipedia.org/wiki/Alpha_particle_X-ray_spectrometer-0.md
category: reference
title: Alpha particle X-ray spectrometer
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Alpha_particle_X-ray_spectrometer
date_saved: 2026-05-05T09:44:08.100387+00:00
instance: kb-cron
parent: alpha-particle-x-ray-spectrometer-20260505-0
summary:
APXS is also an abbreviation for APache eXtenSion tool, an extension for Apache web servers. An alpha particle X-ray spectrometer (APXS) is a spectrometer that analyses the chemical element composition of a sample from scattered alpha particles and fluorescent X-rays after a sample is irradiated with alpha particles and X-rays from radioactive sources. This method of analysing the elemental composition of a sample is most often used on space missions, which require low weight, small size, and minimal power consumption. Other methods (e.g. mass spectrometry) are faster, and do not require the use of radioactive materials, but require larger equipment with greater power requirements. A variation is the alpha proton X-ray spectrometer, such as on the Pathfinder mission, which also detects protons. Over the years several modified versions of this type of instrument such as APS (without X-ray spectrometer) or APXS have been flown: Surveyor 5-7, Mars Pathfinder, Mars 96, Mars Exploration Rover, Phobos, Mars Science Laboratory, the Philae comet lander and the Chandrayaan-3 lunar rover. APS/APXS devices will be included on several upcoming missions. == Sources == Several forms of radiation are used in APXS. They include alpha particles, protons, and X-rays. Alpha particles, protons, and X-rays are emitted


id: atmosphere-space-interactions-monitor-20260505-0
file: data/en.wikipedia.org/wiki/Atmosphere-Space_Interactions_Monitor-0.md
category: reference
title: Atmosphere-Space Interactions Monitor
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Atmosphere-Space_Interactions_Monitor
date_saved: 2026-05-05T09:44:09.250846+00:00
instance: kb-cron
parent: atmosphere-space-interactions-monitor-20260505-0
summary:
Atmosphere-Space Interactions Monitor (ASIM) is a project led by the European Space Agency to place cameras and X-ray/γ-ray detectors on the International Space Station to observe the upper atmosphere in order to study sprites, jets and elves and terrestrial gamma-ray flashes in connection with thunderstorms. It is hoped that measurements of these phenomena from space will contribute to the understanding of Earth's upper atmosphere. The ASIM components, originally planned to be completed in 2014, were launched on 2 April 2018 and mounted on the Columbus External Payload Facility on 13 April 2018. Danish tech company Terma A/S is running the technical part of the project for ESA and DTU Space (National Space Institute) from the Technical University of Denmark provides the scientific leadership of the project. Mission operations will be performed by the Belgian User Support and Operations Centre (B.USOC) in Uccle, Belgium. First results from the measurements revealed that gamma ray bursts form when powerful electric fields course through the atmosphere, just before a lightning bolt travels along the same path. These results were published in July 2019. == Instruments == The ASIM payload has a mass of 314 kg (692 lb) and consists of sub-systems CEPA and DHPU,


id: atmospheric-chemistry-suite-20260505-0
file: data/en.wikipedia.org/wiki/Atmospheric_Chemistry_Suite-0.md
category: reference
title: Atmospheric Chemistry Suite
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Atmospheric_Chemistry_Suite
date_saved: 2026-05-05T09:44:10.564246+00:00
instance: kb-cron
parent: atmospheric-chemistry-suite-20260505-0
summary:
The Atmospheric Chemistry Suite (ACS) is a science payload consisting of three infrared spectrometer channels aboard the ExoMars Trace Gas Orbiter (TGO) orbiting Mars since October 2016. The three channels are: the near-infrared channel (NIR), the mid-infrared channel (MIR), and the far infrared channel (FIR, also called TIRVIM). The ACS was proposed in 2011 by Russian Academy Section and eventually accepted by the European Space Agency (ESA) and Roscosmos as one of two Russian instruments onboard TGO. The instrument was funded by Roscosmos and Centre national d'études spatiales (CNES) of France, and has components of both Russia and France. Its development and fabrication was under Russian leadership. The functionality of all the three channels was confirmed during cruise to Mars. == Objectives == The main objective of the ACS suite is to make an inventory and map minor atmospheric species or trace gases in the atmosphere of Mars. This will allow scientists to profile the upper limits on the methane contents, and to possibly to detect sulfur dioxide (SO2), a gas of volcanic origin. == Channels == The near-infrared channel (NIR), is a compact spectrometer operating in the range of 0.7–1.7 μm with a resolving power of λ/Δλ ~ 20,000


id: atmospheric-infrared-sounder-20260505-0
file: data/en.wikipedia.org/wiki/Atmospheric_infrared_sounder-0.md
category: reference
title: Atmospheric infrared sounder
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Atmospheric_infrared_sounder
date_saved: 2026-05-05T09:44:11.758008+00:00
instance: kb-cron
parent: atmospheric-infrared-sounder-20260505-0
summary:
The atmospheric infrared sounder (AIRS) is one of six instruments flying on board NASA's Aqua satellite, launched on May 4, 2002. The instrument is designed to support climate research and improve weather forecasting. Working in combination with its partner microwave instrument, the Advanced Microwave Sounding Unit (AMSU-A), AIRS observes the global water and energy cycles, climate variation and trends, and the response of the climate system to increased greenhouse gases. AIRS uses infrared technology to create three-dimensional maps of air and surface temperature, water vapor, and cloud properties. AIRS can also measure trace greenhouse gases such as ozone, carbon monoxide, carbon dioxide, and methane. AIRS and AMSU-A share the Aqua satellite with the Moderate Resolution Imaging Spectroradiometer (MODIS), Clouds and the Earth's Radiant Energy System (CERES), and the Advanced Microwave Scanning Radiometer-EOS (AMSR-E). Aqua is part of NASA's "A-train," a series of high-inclination, Sun-synchronous satellites in low Earth orbit designed to make long-term global observations of the land surface, biosphere, solid Earth, atmosphere, and ocean. AIRS data are free and available to the public through the Goddard Earth Sciences Data Information and Services Center. NASA's Jet Propulsion Laboratory in Pasadena, California, manages AIRS for NASA's Science Mission Directorate in Washington,


id: automatic-picture-transmission-20260505-0
file: data/en.wikipedia.org/wiki/Automatic_picture_transmission-0.md
category: reference
title: Automatic picture transmission
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Automatic_picture_transmission
date_saved: 2026-05-05T09:44:12.925851+00:00
instance: kb-cron
parent: automatic-picture-transmission-20260505-0
summary:
The Automatic Picture Transmission (APT) system is an analog image transmission system developed for use on weather satellites. It was introduced in the 1960s and over four decades has provided image data to relatively low-cost user stations at locations in most countries of the world. A user station anywhere in the world can receive local data at least twice a day from each satellite as it passes nearly overhead. == Transmission == === Structure === The broadcast transmission is composed of two image channels, telemetry information, and synchronization data, with the image channels typically referred to as Video A and Video B. All this data is transmitted as a horizontal scan line. A complete line is 2080 pixels long, with each image using 909 pixels and the remainder going to the telemetry and synchronization. Lines are transmitted at 2 per second, which equates to a 4160 words per second, or 4160 baud. === Images === On NOAA POES system satellites, the two images are 4 km / pixel smoothed 8-bit images derived from two channels of the advanced very-high-resolution radiometer (AVHRR) sensor. The images are corrected for nearly constant geometric resolution prior to being broadcast; as such, the images are


id: automatic-picture-transmission-20260505-1
file: data/en.wikipedia.org/wiki/Automatic_picture_transmission-1.md
category: reference
title: Automatic picture transmission
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Automatic_picture_transmission
date_saved: 2026-05-05T09:44:12.925851+00:00
instance: kb-cron
parent: automatic-picture-transmission-20260505-0
summary:
=== Displaying the images === Years ago, to receive APT images, a specialized decoder was required in addition to the receiver to display or print images, much like HF WEFAX (serving the maritime community). Often both receiver and decoder were combined into one unit. Nowadays, with the advent of personal computers, all that is required is dedicated software such as WXtoIMG (many of which offer "free" versions [1]) and a sound card. The sound card acquires and digitizes the slow scan video (in the audible range) coming from the speaker, phones, or line-out of the receiver, and then the software will process the various visible and infrared channels of the AVHRR sensor. ==== Enhanced images ==== Since each channel of the AVHRR sensor is sensitive to only one wavelength of light, each of the two images is luminance only, also known as grayscale. However, different materials tend to emit or reflect with a consistent relative intensity. This has enabled the development of software that can apply a color palette to the images which simulates visible light coloring. If the decoding software knows exactly where the satellite was, it can also overlay outlines and boundaries to help in utilizing the resulting


id: cachecam-20260505-0
file: data/en.wikipedia.org/wiki/Cachecam-0.md
category: reference
title: Cachecam
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Cachecam
date_saved: 2026-05-05T09:44:14.125067+00:00
instance: kb-cron
parent: cachecam-20260505-0
summary:
The Cachecam, a photographic camera, is mounted inside the rover underbelly, at the top of the sample cache of NASA's Perseverance rover mission to Mars. == Overview == The Cachecam's main job is to photograph the top of a sample tube after the sample is gathered in order to verify acquisition before the tube is sealed. It may also take images at other points in the sample processing. The Cachecam will acquire color images of the samples using its 20 megapixel CMOS detector. It is considered an engineering camera. The other sets of engineering cameras on the Mars 2020 Rover are the Navcams and hazcams. == See also == Astrionics List of NASA cameras on spacecraft Mars rover == References == == External links == The Cameras on the Mars 2020 Rover


id: chemistry-and-camera-complex-20260505-0
file: data/en.wikipedia.org/wiki/Chemistry_and_Camera_complex-0.md
category: reference
title: Chemistry and Camera complex
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Chemistry_and_Camera_complex
date_saved: 2026-05-05T09:44:15.324222+00:00
instance: kb-cron
parent: chemistry-and-camera-complex-20260505-0
summary:
Chemistry and Camera complex (ChemCam) is a suite of remote sensing instruments on Mars for the Curiosity rover. As the name implies, ChemCam is actually two different instruments combined as one: a laser-induced breakdown spectroscopy (LIBS) and a Remote Micro Imager (RMI) telescope. The purpose of the LIBS instrument is to provide elemental compositions of rock and soil, while the RMI will give ChemCam scientists high-resolution images of the sampling areas of the rocks and soil that LIBS targets. The LIBS instrument can target a rock or soil sample from up to 7 m (23 ft) away, vaporizing a small amount of it with about 30 5-nanosecond pulses from a 1067 nm infrared laser and then observing the spectrum of the light emitted by the vaporized rock. == Overview == ChemCam has the ability to record up to 6,144 different wavelengths of ultraviolet, visible, and infrared light. Detection of the ball of luminous plasma is done in the visible, near-UV and near-infrared ranges, between 240 nm and 800 nm. The first initial laser testing of the ChemCam by Curiosity on Mars was performed on a rock, N165 ("Coronation" rock), near Bradbury Landing on August 19, 2012. Using the same collection


id: cleo-router-20260505-0
file: data/en.wikipedia.org/wiki/CLEO_(router)-0.md
category: reference
title: CLEO (router)
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/CLEO_(router)
date_saved: 2026-05-05T09:44:30.318956+00:00
instance: kb-cron
parent: cleo-router-20260505-0
summary:
CLEO, the Cisco router in Low Earth Orbit, is an Internet router from Cisco Systems that was integrated into the UK-DMC Disaster Monitoring Constellation satellite built by Surrey Satellite Technology Ltd (SSTL) as a secondary experimental hosted payload, and launched into space with the satellite and sister satellites on a Kosmos 3M rocket from Plesetsk on 27 September 2003. CLEO and the UK-DMC satellite were tested over five years to show the feasibility of extending the Internet to orbit, using both the Internet Protocol and Mobile IP. CLEO was configured by NASA's Glenn Research Center to be used with Virtual Mission Operations Center (VMOC) software from General Dynamics as part of a large internetworking exercise from the field at Vandenberg Air Force Base in June 2004. On 29 March 2007, CLEO was configured for and tested on IPsec and IPv6 use, making this the first use of IPv6 on board a satellite in orbit. The use of CLEO builds on and validates the approach to use of the Internet Protocol articulated by Keith Hogie with NASA Goddard and first demonstrated as part of the Operating Missions as Nodes on the Internet (OMNI) effort on board the UoSAT-12 satellite built by


id: consert-20260505-0
file: data/en.wikipedia.org/wiki/CONSERT-0.md
category: reference
title: CONSERT
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/CONSERT
date_saved: 2026-05-05T09:44:31.535643+00:00
instance: kb-cron
parent: consert-20260505-0
summary:
CONSERT (COmet Nucleus Sounding Experiment by Radiowave Transmission) is a scientific experiment on board the European Space Agency's Rosetta mission, launched in 2004, to provide information about the deep interior of the comet 67P/Churyumov-Gerasimenko upon the probe's rendezvous with the comet in 2014. The CONSERT radar was to perform tomography of the nucleus by measuring electromagnetic wave propagation from the Philae lander and the Rosetta orbiter throughout the comet nucleus in order to determine its internal structures and to deduce information on its composition. The related lander and orbiter electronics were provided by France and both antennas were constructed in Germany. The experiment was designed and built in France by Laboratoire de Planétologie de Grenoble (LPG now IPAG) and by Service d'Aéronomie in Paris (SA now LATMOS), in Germany by the Max Planck Institute for Solar System Research (MPS) in Göttingen. The Principal Investigator of CONSERT is Dr. Wlodek Kofman (IPAG), Director of Research at CNRS. On 13 November 2014, the experiment unexpectedly provided information to locate Philae after it had bounced into an unknown place. == Scientific objectives == The scientific objectives of the CONSERT experiment are the determination of the main dielectric properties and, through modelling, to set


id: cosmic-dust-analyzer-20260505-0
file: data/en.wikipedia.org/wiki/Cosmic_Dust_Analyzer-0.md
category: reference
title: Cosmic Dust Analyzer
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Cosmic_Dust_Analyzer
date_saved: 2026-05-05T09:44:32.786321+00:00
instance: kb-cron
parent: cosmic-dust-analyzer-20260505-0
summary:
The Cosmic Dust Analyzer (CDA) was a large-area (0.1 m2 total sensitive area) multi-sensor dust instrument included on the Cassini spacecraft, which was launched in 1997 and orbited Saturn from 2004 to 2017. The instrument included a chemical dust analyzer (time-of-flight mass spectrometer), a highly reliable impact ionization detector, and two high rate polarized polyvinylidene fluoride (PVDF) detectors. Over 7 years en route to Saturn, the CDA analysed the interplanetary dust cloud, the stream of interstellar dust, and Jupiter dust streams. During 13 years in orbit around Saturn, the CDA studied the E ring, dust in the plumes of Enceladus, and dust in Saturn's environment. == Overview == The Cosmic Dust Analyzer was the seventh dust instrument from the Max Planck Institute for Nuclear Physics (MPIK), Heidelberg (Germany) following the dust detectors on the HEOS 2 satellite and dust detectors on the Galileo and Ulysses space probes and the more complex dust analyzers on the Helios spacecraft, the Giotto and VeGa spacecraft to Halley's Comet. The new dust analyzer system was developed by a team of scientists led by Eberhard Grün and engineers led by Dietmar Linkert to analyze dust in the Saturn system on board the Cassini spacecraft. This


id: cosmic-ray-subsystem-20260505-0
file: data/en.wikipedia.org/wiki/Cosmic_Ray_Subsystem-0.md
category: reference
title: Cosmic Ray Subsystem
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Cosmic_Ray_Subsystem
date_saved: 2026-05-05T09:44:34.007122+00:00
instance: kb-cron
parent: cosmic-ray-subsystem-20260505-0
summary:
Cosmic Ray Subsystem (CRS, or Cosmic Ray System) is an instrument aboard the Voyager 1 and Voyager 2 spacecraft of the NASA Voyager program, and it is an experiment to detect cosmic rays. The CRS includes a High-Energy Telescope System (HETS), Low-Energy Telescope System (LETS), and The Electron Telescope (TET). It is designed to detect energetic particles and some of the requirements were for the instrument to be reliable and to have enough charge resolution. It can also detect the energetic particles like protons from the Galaxy or Earth's Sun. As of 2019, CRS is one of the active remaining instruments on both Voyager spacecraft. It is described by as being able to detect electrons from 3–110 MeV and cosmic ray nuclei 1–500 MeV/n. All three systems used solid-state detectors. CRS is one of the five fields and particle experiments on each spacecraft. One of the goals is to gain a deeper understanding of the solar wind. Other objects of study including electrons and nuclei from planetary magnetospheres and from outside the Solar System. In the summer of 2019, the heater for the CRS on Voyager 2 was turned off to save power; however, although it cooled off, it was


id: diviner-radiometer-20260505-0
file: data/en.wikipedia.org/wiki/Diviner_(radiometer)-0.md
category: reference
title: Diviner (radiometer)
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Diviner_(radiometer)
date_saved: 2026-05-05T09:44:35.175772+00:00
instance: kb-cron
parent: diviner-radiometer-20260505-0
summary:
Diviner, also referred to as the Diviner Lunar Radiometer Experiment (DLRE), is an infrared radiometer aboard NASA's Lunar Reconnaissance Orbiter, part of the Lunar Precursor Robotic Program which is studying the Moon. It has been used to create temperature maps of the Moon's surface, as well as detect ice deposits and surface composition. The instrument has measured temperatures of −247 °C (−412.6 °F) in a crater at the northern pole and −238 °C (−396.4 °F) in craters at the southern pole. On 9 October 2009, the Diviner team announced the detection of a hot spot on the Moon at the location of the LCROSS spacecraft impact site. == References == == External links == Diviner Lunar Radiometer Experiment at UCLA


id: doris-satellite-system-20260505-0
file: data/en.wikipedia.org/wiki/DORIS_(satellite_system)-0.md
category: reference
title: DORIS (satellite system)
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/DORIS_(satellite_system)
date_saved: 2026-05-05T09:44:36.342174+00:00
instance: kb-cron
parent: doris-satellite-system-20260505-0
summary:
DORIS is a French satellite system used for the determination of satellite orbits (e.g. TOPEX/Poseidon) and for positioning. The name is an acronym of "Doppler Orbitography and Radiopositioning Integrated by Satellite" or, in French, Détermination d'Orbite et Radiopositionnement Intégré par Satellite. == Principle == Ground-based radio beacons emit a signal which is picked up by receiving satellites. This is in reverse configuration to other GNSS, in which the transmitters are space-borne and receivers are in majority near the surface of the Earth. A frequency shift of the signal occurs that is caused by the movement of the satellite (Doppler effect). From this observation satellite orbits, ground positions, as well as other parameters can be derived. == Organization == DORIS is a French system which was initiated and is maintained by the French Space Agency (CNES). It is operated from Toulouse. == Ground segment == The ground segment includes about 50-60 ground stations, equally distributed over the Earth and ensure a good coverage for orbit determination. For the installation of a beacon only electricity is required because the station only emits a signal but does not receive any information. DORIS beacons transmit to the satellites on two UHF frequencies, 401.25 MHz


id: dual-segmented-langmuir-probe-20260505-0
file: data/en.wikipedia.org/wiki/Dual_segmented_Langmuir_probe-0.md
category: reference
title: Dual segmented Langmuir probe
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Dual_segmented_Langmuir_probe
date_saved: 2026-05-05T09:44:37.548960+00:00
instance: kb-cron
parent: dual-segmented-langmuir-probe-20260505-0
summary:
Dual Segmented Langmuir Probe (DSLP) is an instrument developed primarily by Czech researchers and engineers to study the magnetospheric background plasma flown on board the spacecraft of the European Space Agency (ESA) Proba 2. Data acquired by DSLP will be used to reach these specific scientific goals: Directional Measurements: Contrary to classical Langmuir probes, the new DSLP concept of data acquisition from the independent segments will enable to study also plasma characteristics in different directions. This should provide for example estimations of plasma flow velocity. Typically in the presence of magnetic field, electron temperatures are observed to be slightly different in the direction parallel and perpendicular to the magnetic field lines. This temperature anisotropy should be measured with DSLP by way of directional data acquisition. Non-Maxwellian Features in Ionospheric Plasma: Classical theories for LPs are typically developed for plasmas in a thermodynamic equilibrium, that is for particle populations possessing Maxwellian velocity distribution functions. However, a thermodynamic equilibrium and thus a Maxwellian distribution is an idealized case while the real distribution in many plasma environments often exhibits various non-Maxwellian features, like loss-cone or flat-top distributions or high-energy tails. We intend to adapt the DSLP theoretical model in order to see whether


id: dynamic-albedo-of-neutrons-20260505-0
file: data/en.wikipedia.org/wiki/Dynamic_Albedo_of_Neutrons-0.md
category: reference
title: Dynamic Albedo of Neutrons
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Dynamic_Albedo_of_Neutrons
date_saved: 2026-05-05T09:44:38.794422+00:00
instance: kb-cron
parent: dynamic-albedo-of-neutrons-20260505-0
summary:
The Dynamic Albedo of Neutrons (DAN) instrument is an experiment mounted on the Mars Science Laboratory's Curiosity rover. It is a pulsed sealed-tube neutron source and detector used to measure hydrogen or ice and water at or near the Martian surface. The instrument consists of the detector element (DE) and a 14.1 MeV pulsing neutron generator (PNG). The die-away time of neutrons is measured by the DE after each neutron pulse from the PNG. DAN was provided by the Russian Federal Space Agency, funded by Russia and is under the leadership of Principal Investigator Igor Mitrofanov. == History == On August 18, 2012 (sol 12), DAN was turned on, marking the success of a Russian-American collaboration on the surface of Mars and the first working Russian science instrument on the Martian surface since Mars 3 stopped transmitting over forty years ago. The instrument is designed to detect subsurface water. On March 18, 2013 (sol 218), NASA reported evidence of mineral hydration, likely hydrated calcium sulfate, in several rock samples including the broken fragments of "Tintina" rock and "Sutton Inlier" rock as well as in veins and nodules in other rocks like "Knorr" rock and "Wernicke" rock. Analysis using the rover's


id: enceladus-icy-jet-analyzer-20260505-0
file: data/en.wikipedia.org/wiki/Enceladus_Icy_Jet_Analyzer-0.md
category: reference
title: Enceladus Icy Jet Analyzer
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Enceladus_Icy_Jet_Analyzer
date_saved: 2026-05-05T09:44:40.032692+00:00
instance: kb-cron
parent: enceladus-icy-jet-analyzer-20260505-0
summary:
The Enceladus Icy Jet Analyzer (ENIJA) is a time-of-flight mass spectrometer developed to search for prebiotic molecules like amino acids and biosignatures in the plumes of Saturn's moon Enceladus. Most of the ice particles in Enceladus's plume have been shown to be direct samples of subsurface waters, offering an opportunity to assess its internal ocean's geochemical and habitability potential without having to land and drill through the ice. The ENIJA instrument has been formally proposed to fly on two missions: the Enceladus Life Finder (ELF), and on the Explorer of Enceladus and Titan (E2T). == Description == The instrument is based on the principle of impact ionization and is optimized for the analysis of high dust fluxes and number densities as typically occur during Enceladus plume crossings. Impact ionization shows an excellent sensitivity for compounds embedded in a water ice matrix. Ice particles as small as 0.1 μm at an impact speed of 5 km/s can be analyzed. The mass resolution is > 970 m/dm for typical plume particles in the size range 0.01 to 100 μm. Detection of elemental and molecular species over such a wide mass range permits clear characterization of particle chemistry, simultaneously covering individual ions like


id: europa-clipper-magnetometer-20260505-0
file: data/en.wikipedia.org/wiki/Europa_Clipper_Magnetometer-0.md
category: reference
title: Europa Clipper Magnetometer
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Europa_Clipper_Magnetometer
date_saved: 2026-05-05T09:44:41.220992+00:00
instance: kb-cron
parent: europa-clipper-magnetometer-20260505-0
summary:
The Europa Clipper Magnetometer (ECM) is a spacecraft magnetometer aboard the planned Europa Clipper mission. It will be used to precisely measure Europa's magnetic field during consecutive fly-bys, allowing scientists to potentially confirm the existence of Europa's hypothesised subsurface ocean. If this ocean exists, the instrument will be able to determine its depth and salinity, as well as the thickness of the moon's icy shell. The magnetometer team is led by Margaret Kivelson, with Xianzhe Jia serving as deputy team leader. == Overview == The ECM is a highly sensitive and precise magnetometer used to measure small changes in the characteristics of Europa's magnetic field, studying how they vary according to time and location. The instrument will be stowed in a canister at launch, and will have a total of three flux-gate sensors attached to it. It will deploy to its full length of 8.5 meters (25 feet) in the days after launch. The spacecraft contains over 300 individual sources of magnetic interference, such as magnets in the propulsion valves, and current loops in the solar arrays. As a result, the instrument will be mounted on an 8.5 meter boom to reduce the effect of this contamination, but will still


id: europa-ultraviolet-spectrograph-20260505-0
file: data/en.wikipedia.org/wiki/Europa_Ultraviolet_Spectrograph-0.md
category: reference
title: Europa Ultraviolet Spectrograph
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Europa_Ultraviolet_Spectrograph
date_saved: 2026-05-05T09:44:42.368285+00:00
instance: kb-cron
parent: europa-ultraviolet-spectrograph-20260505-0
summary:
The Europa Ultraviolet Spectrograph (Europa-UVS) is an ultraviolet spectrograph imager that will be flown on board the Europa Clipper mission to Jupiter's moon Europa. The Europa-UVS will be able to detect small erupting plumes and will provide data about the composition and dynamics of Europa's thin exosphere. The Principal Investigator is Kurt Retherford of the Southwest Research Institute (SwRI), and the instrument engineer is Laura Jones-Wilson from JPL. == Overview == The Europa Ultraviolet Spectrograph inherits technology from a series of successful ultraviolet imaging spectrographs (Rosetta-Alice, New Horizons-Alice, LRO-LAMP, Juno-UVS and JUICE-UVS). Europa-UVS observes photons in the 55-210 nm wavelength range, along a 7.5° slit. A radiation-hardened integrated circuit will be incorporated to meet the radiation requirements. The Europa-UVS offers additional capabilities to locate and characterize plumes erupting from Europa's surface. UVS will also investigate the composition and chemistry of Europa's atmosphere, its surface, and study how energy and mass flow around the moon and its environment. The instrument is a sensitive imaging spectrograph that can observe in the ultraviolet spectral range of 55 nm to 210 nm and can achieve a spectral resolution of <0.6 nm. The instrument does not contain a scan mirror, so the spacecraft must provide


id: fields-20260505-0
file: data/en.wikipedia.org/wiki/FIELDS-0.md
category: reference
title: FIELDS
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/FIELDS
date_saved: 2026-05-05T09:44:43.570266+00:00
instance: kb-cron
parent: fields-20260505-0
summary:
FIELDS is a science instrument on the Parker Solar Probe (PSP), designed to measure magnetic fields in the solar corona during its mission to study the Sun. It is one of four major investigations on board PSP, along with WISPR, ISOIS, and SWEAP. It features three magnetometers. FIELDS is planned to help answer an enduring questions about the Sun, such as why the solar corona is so hot compared to the surface of the Sun and why the solar wind is so fast (a million miles per hour). The host spacecraft, Parker Solar Probe, was launched by a Delta IV Heavy on August 12, 2018 from Florida, USA. On August 13, 2018 FIELDS became the first instrument to be activated including beginning deployment of the four whip antennas (clamps unlocked) and extension of the magnetometer boom. On September 4, 2018 the whip antennas were deployed. == Overview == FIELDS features three magnetometers: two are fluxgate magnetometers, and the third is a search-coil magnetometer. It has five voltage sensors, four of which extend beyond the spacecraft's heatshield and must directly endure the intense conditions at the planned distances of less than 10 solar radii to the Sun. For best scientific observations,


id: foxsi-sounding-rocket-20260505-0
file: data/en.wikipedia.org/wiki/FOXSI_Sounding_Rocket-0.md
category: reference
title: FOXSI Sounding Rocket
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/FOXSI_Sounding_Rocket
date_saved: 2026-05-05T09:44:44.693883+00:00
instance: kb-cron
parent: foxsi-sounding-rocket-20260505-0
summary:
The Focusing Optics X-ray Solar Imager, or FOXSI, is a sounding rocket payload built by UC Berkeley and led by Säm Krucker to test high energy grazing-incidence focusing optics paired with solid-state pixelated detectors to observe the Sun. FOXSI is composed of seven identical Wolter-I telescope modules, as well as Silicon and Cadmium Telluride strip detectors originally developed for the HXT telescope on the Japanese Hitomi mission. The FOXSI payload flew two times, most recently in 2014 and previously in 2012, on the Black Brant IX sounding rocket. Like most sounding rockets, FOXSI flew for approximately 15 minutes per mission and observed the Sun for about 5 minutes while in space. During its first flight, FOXSI successfully imaged a solar microflare in the hard x-ray band for the first time. FOXSI's third mission, led by Lindsay Glesener of the University of Minnesota, had a successful launch on September 7, 2018, from White Sands, New Mexico. This iteration of the payload included a combination of Silicon and improved Cadmium Telluride detectors, as well as one CMOS soft x-ray detector. Two of the telescope modules were updated from 7-shell to 10-shell configurations, and the payload also introduced collimator technology to reduce the


id: galileo-and-ulysses-dust-detectors-20260505-0
file: data/en.wikipedia.org/wiki/Galileo_and_Ulysses_Dust_Detectors-0.md
category: reference
title: Galileo and Ulysses Dust Detectors
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Galileo_and_Ulysses_Dust_Detectors
date_saved: 2026-05-05T09:44:45.895848+00:00
instance: kb-cron
parent: galileo-and-ulysses-dust-detectors-20260505-0
summary:
The Galileo and Ulysses Dust Detectors are almost identical dust instruments on the Galileo and Ulysses missions. The instruments are large-area (0.1 m2 sensitive area) highly reliable impact ionization detectors of sub-micron and micron sized dust particles. With these instruments the interplanetary dust cloud was characterized between Venus’ and Jupiter's orbits and over the solar poles. A stream of interstellar dust passing through the planetary system was discovered. Close to and inside the Jupiter system streams nanometer sized dust particles that were emitted from volcanoes on Jupiter's moon Io and ejecta clouds around the Galilean moons were discovered and characterized. == Overview == Following the first dust instruments from the Max Planck Institute for Nuclear Physics (MPIK), Heidelberg (Germany) on the HEOS 2 satellite and the Helios spacecraft a new dust instrument was developed by a Team of Scientists and Engineers of Eberhard Grün to detect cosmic dust in the outer planetary system. This instrument had 10 times larger sensitive area (0.1 m2) and employed a multiple coincidence of impact signals in order to cope with the low fluxes of cosmic dust and the hostile environment in the outer planets magnetospheres. The Galileo and Ulysses dust detectors use impact ionization


id: gamma-ray-spectrometer-2001-mars-odyssey-20260505-0
file: data/en.wikipedia.org/wiki/Gamma_Ray_Spectrometer_(2001_Mars_Odyssey)-0.md
category: reference
title: Gamma Ray Spectrometer (2001 Mars Odyssey)
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Gamma_Ray_Spectrometer_(2001_Mars_Odyssey)
date_saved: 2026-05-05T09:44:47.060034+00:00
instance: kb-cron
parent: gamma-ray-spectrometer-2001-mars-odyssey-20260505-0
summary:
The Gamma Ray Spectrometer (GRS) is a gamma-ray spectrometer on the 2001 Mars Odyssey spacecraft, a space probe orbiting the planet Mars since 2001. Part of NASA's Mars Surveyor 2001 program, it returns geological data about Mars's surface such as identifying elements and the location of water. It is maintained by the Lunar and Planetary Laboratory at the University of Arizona in the United States. This instrument has mapped the distribution surface hydrogen, thought to trace water in the surface layer of Martian soil. == GRS specifications == The Gamma Ray Spectrometer weighs 30.5 kilograms (67 lb) and uses 32 watts of power. Along with its cooler, it measures 468 by 534 by 604 millimetres (18.4 by 21.0 by 23.8 in). The detector is a photodiode made of a 1.2-kilogram (2.6 lb) germanium crystal, reverse biased to about 3 kilovolts, mounted at the end of a 6-metre (20 ft) boom to minimize interferences from the gamma radiation produced by the spacecraft itself. Its spatial resolution is about 300 kilometres (190 mi). The neutron spectrometer is 173 by 144 by 314 millimetres (6.8 by 5.7 by 12.4 in). The high-energy neutron detector measures 303 by 248 by 242 millimetres (11.9 by


id: geostationary-carbon-cycle-observatory-20260505-0
file: data/en.wikipedia.org/wiki/Geostationary_Carbon_Cycle_Observatory-0.md
category: reference
title: Geostationary Carbon Cycle Observatory
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Geostationary_Carbon_Cycle_Observatory
date_saved: 2026-05-05T09:44:48.413911+00:00
instance: kb-cron
parent: geostationary-carbon-cycle-observatory-20260505-0
summary:
Geostationary Carbon Cycle Observatory (GeoCarb or GeoCARB) was an intended NASA Venture-class Earth observation mission that was designed to measure the carbon cycle, building off the success of OCO-2, but in geostationary orbit. GeoCarb was to be stationed over the Americas and make observations between 50° North and South latitudes in geostationary Earth orbit 35,786 km above the equator. Its primary mission was to conduct observations of vegetation health and stress by measuring solar-induced fluorescence, as well as observe the processes that govern the movement of greenhouse gases in the carbon cycle. Selected by NASA in 2016. It was originally intended to be mounted on a commercial geostationary communication satellite operated by SES S.A., but instead NASA, in February 2022, sought a standalone spacecraft to carry GeoCarb. On 28 November 2022, NASA announced the cancellation of development of the GeoCarb mission, citing cost overruns, technical concerns, and the availability of other options to measure and observe greenhouse gases, like the EMIT instrument on the ISS and the upcoming Earth System Observatory. NASA worked with the University of Oklahoa to close the project which was scheduled to be launched around the end of June 2025. GeoCarb was a joint collaboration between


id: geostationary-earth-radiation-budget-20260505-0
file: data/en.wikipedia.org/wiki/Geostationary_Earth_Radiation_Budget-0.md
category: reference
title: Geostationary Earth Radiation Budget
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Geostationary_Earth_Radiation_Budget
date_saved: 2026-05-05T09:44:49.626063+00:00
instance: kb-cron
parent: geostationary-earth-radiation-budget-20260505-0
summary:
The Geostationary Earth Radiation Budget (GERB) is an instrument aboard EUMETSAT's Meteosat Second Generation geostationary satellites designed to make accurate measurements of the Earth radiation budget. It was produced by a European consortium consisting of the United Kingdom, Belgium and Italy. The first, known as GERB 2, was launched on 28 August 2002 on an Ariane 5 rocket. The second, GERB 1, was launched on 21 December 2005, and the third, GERB3, on 5 July 2012. The last GERB 4 device was launched 14 July 2015. The first launched GERB 2 on MSG 1 is currently situated over the Indian Ocean at 41.5°E, while GERBs 1 and 3 on MSG 2 and 3 are still located over the standard Africa EUMETSAT position. GERB 4 on MSG is yet to become operational. == Scientific motivations and objectives == The unprecedented rate of atmospheric CO2 increase occurring since the Industrial Revolution due to human activity is of much concern to scientists as it has occurred an order of magnitude faster than planet Earth has ever experienced. Climate models described as Global Circulation Models (GCMs) are currently avenue to investigate and try and predict how Earth climate will change in response such an


id: geostationary-earth-radiation-budget-20260505-1
file: data/en.wikipedia.org/wiki/Geostationary_Earth_Radiation_Budget-1.md
category: reference
title: Geostationary Earth Radiation Budget
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Geostationary_Earth_Radiation_Budget
date_saved: 2026-05-05T09:44:49.626063+00:00
instance: kb-cron
parent: geostationary-earth-radiation-budget-20260505-0
summary:
== GERB device and calibration == The GERB project is led by the Space and Atmospheric Group (SPAT) based at Imperial College UK, with Professor John. E. Harries the original Principal Investigator and now succeeded by Dr Helen Brindley. The devices themselves were constructed by Rutherford Appleton Laboratory using an Italian 3 mirror silver telescope and electronics designed by the Space Science center at the University of Leicester UK. Each of the four completed GERB devices underwent extensive ground radiometric calibration in a Vacuum Calibration Chamber (VCC) at the Earth Observation and Characterization Facility (EOCF) also the Imperial College and designed by Ray Wrigley. Such tests included confirmation of linearity, LW radiometric gain determination using Warm and Cold BlackBodies (WBB & CBB), SW gain determination using Visible Calibration Source (VISCS) lamp and spot checks on the system level spectral response. Each GERB device makes use of a linear array of blackened thermopile detectors manufactured by Honeywell, which stare at the Earth on each 100rpm rotation of the MSG platform by making use of a De-Scan Mirror (DSM). Hence a column of the Earth disk is taken on each revolution allowing 250x256 Total channel samples followed by 250x256 SW samples with


id: global-ecosystem-dynamics-investigation-20260505-0
file: data/en.wikipedia.org/wiki/Global_Ecosystem_Dynamics_Investigation-0.md
category: reference
title: Global Ecosystem Dynamics Investigation
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Global_Ecosystem_Dynamics_Investigation
date_saved: 2026-05-05T09:44:50.820843+00:00
instance: kb-cron
parent: global-ecosystem-dynamics-investigation-20260505-0
summary:
Global Ecosystem Dynamics Investigation (GEDI, pronounced ) is a LiDAR altimeter mission by NASA to measure how deforestation has contributed to atmospheric CO2 concentrations. A full-waveform LiDAR was attached to the International Space Station to provide the first global, high-resolution observations of forest vertical structure. This will allow scientists to map habitats and biomass, particularly in the tropics, providing detail on the Earth's carbon cycle. Although GEDI has been originally developed to monitor biomass and carbon cycle, other potentials have been also investigated such as inland water level monitoring and DSM generation. The Principal Investigator is Ralph Dubayah, at the University of Maryland. The Deputy Principal Investigator & Instrument Scientist is J. Bryan Blair at NASA's Goddard Space Flight Center. == Overview == GEDI was competitively selected as a NASA Earth Ventures Instrument (EVI) mission in 2014. Cost-capped at $94 M, GEDI is led by the University of Maryland in collaboration with NASA Goddard Space Flight Center. Climate change is closely tied to that of the carbon cycle. GEDI produces high resolution laser ranging observations of the 3D structure of the forests of Earth, which will provide answers to how deforestation has contributed to atmospheric CO2 concentrations, how much carbon


id: global-ozone-monitoring-by-occultation-of-stars-20260505-0
file: data/en.wikipedia.org/wiki/Global_Ozone_Monitoring_by_Occultation_of_Stars-0.md
category: reference
title: Global Ozone Monitoring by Occultation of Stars
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Global_Ozone_Monitoring_by_Occultation_of_Stars
date_saved: 2026-05-05T09:44:51.994880+00:00
instance: kb-cron
parent: global-ozone-monitoring-by-occultation-of-stars-20260505-0
summary:
Global Ozone Monitoring by Occultation of Stars (GOMOS), is an instrument on board the European satellite Envisat launched 1 March 2002. It is the first space instrument dedicated to the study of the atmosphere of the Earth by the technique of stellar occultation. The spectrum of stars in the ultraviolet, visible and the near infrared parts of the electromagnetic spectrum is observed. It is aimed to use GOMOS to build a climatology of ozone and related species in the middle atmosphere (15 to 100 km). == Instrument details == The 250-680 nm spectral domain is used for the determination of O3, NO2, NO3−, aerosols and temperature. In addition, two high spectral resolution channels centred at 760 and 940 nm allow measurements of O2 and H2O and two fast photometers are used to correct star scintillation perturbations and to determine high vertical resolution temperature profiles. Global latitude coverage is obtained with up to 40 stellar occultations per orbit from South Pole to North Pole. Data acquired on dark limb (night-time) are of better quality than on bright limb (day-time) because of a smaller perturbation by background light. == History == GOMOS was first proposed in 1988 as an Announcement of Opportunity


id: global-scale-observations-of-the-limb-and-disk-20260505-0
file: data/en.wikipedia.org/wiki/Global-scale_Observations_of_the_Limb_and_Disk-0.md
category: reference
title: Global-scale Observations of the Limb and Disk
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Global-scale_Observations_of_the_Limb_and_Disk
date_saved: 2026-05-05T09:44:53.195103+00:00
instance: kb-cron
parent: global-scale-observations-of-the-limb-and-disk-20260505-0
summary:
Global-scale Observations of the Limb and Disk (GOLD) is a heliophysics Mission of Opportunity (MOU) for NASA's Explorers program. Led by Richard Eastes at the Laboratory for Atmospheric and Space Physics, which is located at the University of Colorado Boulder, GOLD's mission is to image the boundary between Earth and space in order to answer questions about the effects of solar and atmospheric variability of Earth's space weather. GOLD was one of 11 proposals selected, of the 42 submitted, for further study in September 2011. On 12 April 2013, NASA announced that GOLD, along with the Ionospheric Connection Explorer (ICON), had been selected for flight in 2017. GOLD, along with its commercial host satellite SES-14, launched on 25 January 2018. == Mission concept and history == GOLD is intended to perform a two-year mission imaging Earth's thermosphere and ionosphere from geostationary orbit. GOLD is a two-channel far-ultraviolet (FUV) imaging spectrograph built by the Laboratory for Atmospheric and Space Physics at the University of Colorado Boulder and flown as a hosted payload on the commercial communications satellite SES-14. Additional organizations participating in the GOLD mission include the National Center for Atmospheric Research, Virginia Tech, the University of California, Berkeley, the University


id: gravity-science-juno-20260505-0
file: data/en.wikipedia.org/wiki/Gravity_science_(Juno)-0.md
category: reference
title: Gravity science (Juno)
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Gravity_science_(Juno)
date_saved: 2026-05-05T09:44:54.396191+00:00
instance: kb-cron
parent: gravity-science-juno-20260505-0
summary:
The Gravity Science experiment and instrument set aboard the Juno Jupiter orbiter is designed to monitor Jupiter's gravity. It maps Jupiter's gravitational field, which will allow the interior of Jupiter to be better understood. It uses special hardware on Juno, and also on Earth, including the high-gain K-band and X-band communication systems of the Deep Space Network as well as Juno's Ka-band Translator System (KaTS). These components work together to detect minute changes in radio frequency (Doppler shift) to measure the spacecraft's velocity over time. The KaTS box was funded by the Italian Space Agency and overseen by professor Luciano Iess from University La Sapienza in Rome. KaTS detects signals coming from the DSN on Earth, and then sends replies in a very precise way that allows the velocity of Juno to be determined to within 0.001 millimeters per second. The spacecraft receives a tone signal on the X or Ka band and then replies using the Ka-band radio. As the spacecraft traverses the space near Jupiter, the planet, and even variations in the planets interior, cause a variation in Juno velocity. The gravity science experiment measures these velocity changes using a combination of hardware on Earth and the spacecraft,


id: habitability-brine-irradiation-and-temperature-20260505-0
file: data/en.wikipedia.org/wiki/Habitability,_Brine_Irradiation_and_Temperature-0.md
category: reference
title: Habitability, Brine Irradiation and Temperature
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Habitability,_Brine_Irradiation_and_Temperature
date_saved: 2026-05-05T09:44:55.573215+00:00
instance: kb-cron
parent: habitability-brine-irradiation-and-temperature-20260505-0
summary:
Habitability, Brine Irradiation and Temperature (HABIT) is an instrument designed to harvest water from the Mars atmosphere, an experiment that might pave the way to future water farms on Mars. As part of ESA's ExoMars-2 mission, the instrument was planned to be placed on board the Kazachok lander. The launch of ExoMars-2 has been postponed to 2028. == Instrument description == HABIT is composed of two major components: BOTTLE (Brine Observation Transition to Liquid Experiment) and ENVPACK (Environmental Package). BOTTLE contains six containers protected by HEPA filters, filled with salts that will collect atmospheric water through deliquescence. Sensors in each container will measure hydration and a state in which brine formed. Salts in the instrument can be dehydrated to allow indefinite operations of the instrument. ENVPACK will contain instruments measuring ultraviolet irradiance, ground temperature, and a temperature of the atmosphere in three different directions. Most of the ENVPACK instruments were already used in Rover Environmental Monitoring Station of the NASA's Curiosity rover. The Principal Investigator of HABIT is Javier Martin-Torres. == Scientific objectives == The objectives of HABIT are: to investigate (and quantify) the habitability of the landing site in terms of availability of water, ultraviolet radiation, and temperature ranges


id: hazcam-20260505-0
file: data/en.wikipedia.org/wiki/Hazcam-0.md
category: reference
title: Hazcam
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Hazcam
date_saved: 2026-05-05T09:44:56.826839+00:00
instance: kb-cron
parent: hazcam-20260505-0
summary:
Hazcams (short for hazard avoidance cameras) are photographic cameras mounted on the front and rear of NASA's Spirit, Opportunity, Curiosity and Perseverance rover missions to Mars and on the lower front portion of the Chinese Yutu rover mission to the Moon and the Zhurong rover to Mars. == Overview == The Curiosity rover's hazcams are sensitive to visible light and return black and white images of resolution 1024 × 1024 pixels. These images are used by the rovers' internal computer to autonomously navigate around hazards. Due to their positioning on both sides of the rovers, simultaneous images taken by either both front or both rear cameras can be used to produce a 3D map of the immediate surroundings. As the cameras are fixed (i.e. can not move independently of the rover), they have a wide field of view (approximately 120° both horizontally and vertically) to allow a large amount of terrain to be visible. They are considered engineering cameras since they were not designed to be used for scientific experiments. The other set of engineering cameras on the rovers are the navcams. The safe landing of the Mars Science Laboratory was initially confirmed using the vehicle's hazcams. The Perseverance cameras


id: heat-flow-and-physical-properties-package-20260505-0
file: data/en.wikipedia.org/wiki/Heat_Flow_and_Physical_Properties_Package-0.md
category: reference
title: Heat Flow and Physical Properties Package
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Heat_Flow_and_Physical_Properties_Package
date_saved: 2026-05-05T09:44:58.005408+00:00
instance: kb-cron
parent: heat-flow-and-physical-properties-package-20260505-0
summary:
The Heat Flow and Physical Properties Package (HP3) is a science payload on board the InSight lander that features instruments to study the heat flow and other thermal properties of Mars. One of the instruments, a burrowing probe nicknamed "the mole", was designed to penetrate 5 m (16 ft) below Mars' surface. In March 2019, the mole burrowed a few centimeters, but then became unable to make progress due to various factors. In the following year further attempts were made to resolve the issues, with little net progress. On January 14, 2021, it was announced that efforts to drill into the martian surface using the device had been terminated. HP3 was provided by the German Aerospace Center (DLR). The hammering mechanism inside the mole was designed by the Polish company Astronika and the Space Research Centre of the Polish Academy of Sciences under contract and in cooperation with DLR. The Principal Investigator is Tilman Spohn from the German Aerospace Center. == Overview == The mission goal was to understand the origin and diversity of terrestrial planets. Information from the HP3 heat flow package was expected to reveal whether Mars and Earth formed from the same material, and determine how active


id: heat-flow-and-physical-properties-package-20260505-1
file: data/en.wikipedia.org/wiki/Heat_Flow_and_Physical_Properties_Package-1.md
category: reference
title: Heat Flow and Physical Properties Package
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Heat_Flow_and_Physical_Properties_Package
date_saved: 2026-05-05T09:44:58.005408+00:00
instance: kb-cron
parent: heat-flow-and-physical-properties-package-20260505-0
summary:
=== Penetration efforts === In March 2019, the HP3 began burrowing into the surface sand, but became stalled after several centimeters by what was initially suspected to be a large rock. Further analysis and testing with a replica model on Earth suggested the problem may be due to insufficient friction. In June 2019, more evidence for this was revealed when the support structure was lifted off of the HP3 mole. The Martian regolith appeared to be compressed, leaving a gap around the probe. A technique was implemented using the lander's robotic arm to press on the soil near the probe to increase soil friction. Ultimately, this method was not able to generate enough downward force, since the HP3 probe was at the limit of the arm's range. Instead, the team used the robotic scoop to pin the probe against the edge of its hole. This method appeared successful initially, as the probe continued to dig for two weeks, until it was flush with the surface. At this time, the exposed top of the probe was too small for the scoop to press against, so the scoop was re-positioned to press down on the soil near the probe. Unfortunately, this caused


id: helios-dust-instrumentation-20260505-0
file: data/en.wikipedia.org/wiki/Helios_Dust_Instrumentation-0.md
category: reference
title: Helios Dust Instrumentation
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Helios_Dust_Instrumentation
date_saved: 2026-05-05T09:44:59.180833+00:00
instance: kb-cron
parent: helios-dust-instrumentation-20260505-0
summary:
The Helios 1 and 2 spacecraft each carried two dust instruments to characterize the Zodiacal dust cloud inside the Earth’s orbit down to spacecraft positions 0.3 AU from the sun. The Zodiacal light instrument measured the brightness of light scattered by interplanetary dust along the line of sight. The in situ Micrometeoroid analyzer recorded impacts of meteoroids onto the sensitive detector surface and characterized their composition. The instruments delivered radial profiles of their measured data. Comet or meteoroid streams, and even interstellar dust were identified in the data. == Overview == The two Helios spacecraft were the result of a joint venture of West Germany's space agency DLR and NASA. The spacecraft were built in Germany and launched from Cape Canaveral Air Force Station, Florida. Helios 1 was launched in December 1974 onto an elliptic orbit between 1 and 0.31 au. Helios 2 followed in January 1976 and reached 0.29 au perihelion distance. The orbital periods were about 6 months. The Helios spacecraft were spinning with the spin axis perpendicular to the ecliptic plane. The Helios 1 spin axis pointed to ecliptic north whereas the Helios 2 orientation was inverted and the spin axis pointed to ecliptic south. The despun


id: helios-dust-instrumentation-20260505-1
file: data/en.wikipedia.org/wiki/Helios_Dust_Instrumentation-1.md
category: reference
title: Helios Dust Instrumentation
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Helios_Dust_Instrumentation
date_saved: 2026-05-05T09:44:59.180833+00:00
instance: kb-cron
parent: helios-dust-instrumentation-20260505-0
summary:
The South sensor was shielded by the spacecraft rim from direct sun light, whereas the ecliptic sensor was directly exposed to the intense solar radiation (up to 13 kW/m2). Therefore, the interior of the sensor was protected by a 0.3 μm thick aluminized parylene film which was attached to the first entrance grid. In order to study the effect of micrometeoroids penetrating the film, extensive dust accelerator studies with various materials were performed. It was shown that the penetration limit of the Helios film depends strongly on the density of meteoroids. Impact experiments with a lab version of the Helios micrometeoroid sensor were performed using several materials at the accelerators at the Max Planck Institute for Nuclear Physics in Heidelberg and at the Ames Research Center, ARC, in Moffet Field. The projectile materials included iron (Fe), quartz, glass, aluminium (Al), aluminium oxide (Al2O3), polystyrene, and kaolin. The mass resolution of the mass spectra of the Helios sensors was low R = M Δ M ∼ 10 {\displaystyle R={\cfrac {M}{\Delta M}}\sim 10} , i.e. only ions of atomic mass 10 Da could be separated from ions of mass 11 Da. These mass spectra served as reference for the spectra obtained in


id: high-resolution-stereo-camera-20260505-0
file: data/en.wikipedia.org/wiki/High_Resolution_Stereo_Camera-0.md
category: reference
title: High Resolution Stereo Camera
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/High_Resolution_Stereo_Camera
date_saved: 2026-05-05T09:45:00.340228+00:00
instance: kb-cron
parent: high-resolution-stereo-camera-20260505-0
summary:
High Resolution Stereo Camera (HRSC) is a camera experiment on Mars Express. A version for Earth called HRSC-AX was also developed, as was a version for Mars 96. It has four main parts: camera head, super resolution channel, instrument frame, and digital unit. At an altitude of 250 km from Mars, SRC can produce images with a resolution of 2.3 meters/pixel of 2.35 km square Mars terrain. It has 9 channels and can produce digital terrain models. A typical image from HRSC of Mars has a resolution ranging from 12.5 for nadir (directly down) to 25 m/pixel for the furthest off-nadir shots, which can be up to 18.9 degrees. By 2012, about 61.5% of the surface of Mars was mapped at a resolution of at least 20 meters per pixel by the Mars Express mission using this camera. Another area of study is repeat imaging, to allow the study of dynamic processes on Mars. Another trick is to make short videos of the Mars surface by taking advantage of the pushbroom nature of the detector. Each section is slightly offset for a different color, but when combined, every view is used to make a short animation. By the start of


id: hiros-20260505-0
file: data/en.wikipedia.org/wiki/HiROS-0.md
category: reference
title: HiROS
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/HiROS
date_saved: 2026-05-05T09:45:01.545763+00:00
instance: kb-cron
parent: hiros-20260505-0
summary:
HiROS (High Resolution Optical System) is a satellite system operating in the visible and near infra-red (NIR) optical range with a 0.5 m ground resolution. It is developed by the German Aerospace Center and will allegedly be used for espionage purposes, according to leaked diplomatic cables. The satellite has a mass of 820 kg, and can be launched from various Soyuz, Vega, or Rockot rockets. It has a revisit time of 24 h. The project was cancelled in 2012. == Instrument performance == The instrument itself has a mass of 190 kg. Its detector has a panchromatic channel between 450 and 900 nm (visible and near IR) with a ground resolution of 0.5 m. In a multichannel operation, it can achieve 2 m ground resolution. It has a signal to noise ratio of 200 and a dynamic range of 1:5000 and uses a 14 bit analog to digital converter. == References == == External links == (in English) www.ifp.uni-stuttgart.de Presentations from 2009


id: inertial-stellar-compass-20260505-0
file: data/en.wikipedia.org/wiki/Inertial_Stellar_Compass-0.md
category: reference
title: Inertial Stellar Compass
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Inertial_Stellar_Compass
date_saved: 2026-05-05T09:45:02.734752+00:00
instance: kb-cron
parent: inertial-stellar-compass-20260505-0
summary:
Inertial Stellar Compass (ISC) was a proposed instrument for an advanced navigation system designed to allow spacecraft to operate more autonomously by enabling precise attitude determination with an accuracy of better than 0.1 degrees across all three axes. It also provides the capability to recover orientation after a power loss. The ISC is small in size and consumes low power to operate. The ISC was developed by NASA as part of New Millennium program's Space Technology 6 project in collaboration with Charles Stark Draper Laboratory. The instrument functions with a combination of a miniaturized star tracker and gyroscopes. It uses a wide field-of-view active pixel star camera and a micro electromechanical system to determine the real-time stellar attitude (orientation) of the spacecraft. It has a mass of 2.5 kg (5.5 lb) and requires 3.5 W power. In 2007, it was successfully deployed and fully operational in space aboard the TacSat-2 spacecraft. As the New Millennium Program had its budget cancelled in 2009, it is unclear whether development of this instrument is ongoing. == References ==


id: infrared-interferometer-spectrometer-and-radiometer-20260505-0
file: data/en.wikipedia.org/wiki/Infrared_interferometer_spectrometer_and_radiometer-0.md
category: reference
title: Infrared interferometer spectrometer and radiometer
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Infrared_interferometer_spectrometer_and_radiometer
date_saved: 2026-05-05T09:45:03.977246+00:00
instance: kb-cron
parent: infrared-interferometer-spectrometer-and-radiometer-20260505-0
summary:
An infrared interferometer spectrometer and radiometer (IRIS) is a scientific instrument of the Voyager space probes which enables the measurement of three distinct properties. The instrument itself consists of two separate instruments that together share a single large-aperture telescope system. The Infrared interferometer spectrometer holds two functions as it can act as a thermometer and/or spectrometer. The thermometer allows for the observance and measurement of heat energy emitting from an object, and the spectrometer enables the identification of various elements, molecules, and compounds which may be present in an atmosphere and/or on the surface of a body. The separate radiometer allows for the measurement of reflected infrared, visible, and ultraviolet light off of a body. == History == Early versions of the IRIS were flown on the 1960s Nimbus 3 and Nimbus 4. In 1971, an early prototype was used on Mariner 9 to examine Mars. == Objectives == The instrument was included, primarily, to meet the following objectives. Determination of atmospheric vertical thermal structure (which in turn aids modeling of atmospheric dynamics). Measurement of the abundances of hydrogen and helium (as a check on theories regarding their ratio in the primitive solar nebula). Determination of the balance of energy


id: infrared-spectrometer-for-exomars-20260505-0
file: data/en.wikipedia.org/wiki/Infrared_Spectrometer_for_ExoMars-0.md
category: reference
title: Infrared Spectrometer for ExoMars
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Infrared_Spectrometer_for_ExoMars
date_saved: 2026-05-05T09:45:05.255251+00:00
instance: kb-cron
parent: infrared-spectrometer-for-exomars-20260505-0
summary:
Infrared Spectrometer for ExoMars (ISEM) was an infrared spectrometer for remote sensing designed to be part of the science payload on board the European Space Agency's Rosalind Franklin rover, tasked to search for biosignatures and biomarkers on Mars. ISEM would provide context assessment of the surface mineralogy in the vicinity of the Rosalind Franklin rover for selection of potential astrobiological targets. The Principal Investigator was Oleg Korablev from the Russian Space Research Institute (IKI). The instrument's use on the rover was cancelled, together with other Russian contributions to the project, after Russian invasion of Ukraine in 2022 and it was replaced by the Welsh-built ENFYS. == Overview == The Infrared Spectrometer for ExoMars (ISEM) was being developed by the Russian Space Research Institute (IKI). It would be the first instance of near-infrared spectroscopy (NIR) observations done from the Mars surface. The instrument would be installed on the Rosalind Franklin rover's mast to measure reflected solar radiation in the near infrared range for context assessment of the surface mineralogy in the vicinity of Rosalind Franklin for selection of potential astrobiological targets. As the number of samples obtained with the drill will be limited, the selection of high-value sites for drilling will


id: integrated-science-investigation-of-the-sun-20260505-0
file: data/en.wikipedia.org/wiki/Integrated_Science_Investigation_of_the_Sun-0.md
category: reference
title: Integrated Science Investigation of the Sun
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Integrated_Science_Investigation_of_the_Sun
date_saved: 2026-05-05T09:45:06.434344+00:00
instance: kb-cron
parent: integrated-science-investigation-of-the-sun-20260505-0
summary:
Integrated Science Investigation of the Sun or IS☉IS, is an instrument aboard the Parker Solar Probe, a space probe designed to study the Sun. IS☉IS is focused on measuring energetic particles from the Sun, including electrons, protons, and ions. The parent spacecraft was launched in early August 2018, and with multiple flybys of Venus will study the heliosphere of the Sun from less than 4 million kilometers or less than 9 solar radii. IS☉IS consists of two detectors, EPI-Lo and EPI-Hi, corresponding to detection of relatively lower and higher energy particles. EPI-Lo is designed to detect from about 20 keV per nucleon up to 15 MeV (mega electronvolts) total energy, and for electrons from about 25 keV up to 1000 keV. EPI-Hi is designed to measure charged particles from about 1– to 200 MeV per nucleon and electrons from about 0.5 to 6 MeV, according to a paper about the device. The shortname includes a symbol for the Sun, a circle with a dot in it: ☉. NASA suggests pronouncing the name as in English. == Operations == By September 2018, IS☉IS had been turned on and first light data was returned. == EPI-Hi == EPI-Hi includes: High Energy Telescope


id: interior-characterization-of-europa-using-magnetometry-20260505-0
file: data/en.wikipedia.org/wiki/Interior_Characterization_of_Europa_using_Magnetometry-0.md
category: reference
title: Interior Characterization of Europa using Magnetometry
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Interior_Characterization_of_Europa_using_Magnetometry
date_saved: 2026-05-05T09:45:07.678711+00:00
instance: kb-cron
parent: interior-characterization-of-europa-using-magnetometry-20260505-0
summary:
The Interior Characterization of Europa using Magnetometry (ICEMAG) is a multi-frequency magnetometer that was proposed to be flown on board the Europa Clipper mission to Jupiter's moon Europa, but its inclusion was cancelled in March 2019. Magnetic induction is a powerful tool for probing the subsurface and determine Europa's ocean depth, salinity, and ice shell thickness, as well as detecting erupting plume activity. The Principal Investigator is Carol Raymond, at NASA's Jet Propulsion Laboratory. On March 5, 2019, NASA's Associate Administrator for the Science Mission Directorate, Thomas Zurbuchen, announced that ICEMAG would no longer be part of the Europa Clipper mission, primarily citing recurring cost increases (over three times the original cost put forward in the proposal). A less complex magnetometer will be included on the mission. == Overview == Magnetic induction is a powerful tool for probing the subsurface. ICEMAG would have observed the magnetic field near Europa with greatly enhanced sensitivity compared to a similar instrument carried by NASA's Galileo spacecraft, which orbited Jupiter from 1995 to 2003. The magnetic field induced in Europa over many frequencies would reveal the ocean depth and ice shell thickness, especially when combined with the REASON ice penetrating radar data and the


id: international-lunar-observatory-20260505-0
file: data/en.wikipedia.org/wiki/International_Lunar_Observatory-0.md
category: reference
title: International Lunar Observatory
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/International_Lunar_Observatory
date_saved: 2026-05-05T09:45:08.826982+00:00
instance: kb-cron
parent: international-lunar-observatory-20260505-0
summary:
The International Lunar Observatory (ILO) is a private scientific and commercial lunar mission by the International Lunar Observatory Association (ILOA Hawai'i) of Kamuela, Hawaii to place a permanent observatory near the South Pole of the Moon to conduct astrophysical studies using an optical telescope and possibly an antenna dish. The mission aims to prove a conceptual design for a lunar observatory that would be reliable, low cost, and fast to implement. A precursor mission, ILO-X consisting of two small imagers (totaling less than 0.6 kg), launched on 15 February 2024 aboard the Intuitive Machines IM-1 mission to the Moon south pole region. It is hoped to be a technology precursor to a future observatories on the Moon, and other commercial initiatives. The ILO-1 mission is being organized by the International Lunar Observatory Association and the Space Age Publishing Company. It was planned to be launched in 2008 with development by SpaceDev, and was first delayed to 2013. The prime contractors originally were Moon Express, providing the MX-1E lander, and Canadensys Aerospace, providing the optical telescope system. The estimated cost in 2004 was of US$50 million. == Overview == The ILO-1 mission, was later scheduled to be launched in July 2020


id: jedi-20260505-0
file: data/en.wikipedia.org/wiki/JEDI-0.md
category: reference
title: JEDI
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/JEDI
date_saved: 2026-05-05T09:45:10.021020+00:00
instance: kb-cron
parent: jedi-20260505-0
summary:
JEDI (Jupiter Energetic-particle Detector Instrument) is an instrument on the Juno spacecraft orbiting planet Jupiter. JEDI coordinates with the several other space physics instruments on the Juno spacecraft to characterize and understand the space environment of Jupiter's polar regions, and specifically to understand the generation of Jupiter's powerful aurora. It is part of a suite of instruments to study the magnetosphere of Jupiter. JEDI consists of three identical detectors that use microchannel plates and foil layers to detect the energy, angle, and types of ion within a certain range. It can detect electrons between 40 and 500 keV (Kilo electron-volts), and hydrogen and oxygen from a few tens of keV to less than 1000 keV (1 MeV). JEDI uses radiation-hardened Application Specific Integrated Circuits (ASIC)s. JEDI was turned on in January 2016 while still en route to Jupiter, to study interplanetary space. JEDI uses solid state detectors (SSDs) to measure the total energy (E) of both the ions and the electrons. The MCP anodes and the SSD arrays are configured to determine the directions of arrivals of the incoming charged particles. The instruments also use fast triple coincidence and optimum shielding to suppress penetrating background radiation and incoming UV foreground.


id: jovian-auroral-distributions-experiment-20260505-0
file: data/en.wikipedia.org/wiki/Jovian_Auroral_Distributions_Experiment-0.md
category: reference
title: Jovian Auroral Distributions Experiment
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Jovian_Auroral_Distributions_Experiment
date_saved: 2026-05-05T09:45:11.241000+00:00
instance: kb-cron
parent: jovian-auroral-distributions-experiment-20260505-0
summary:
Jovian Auroral Distributions Experiment (JADE) is an instrument that detects and measures ions and electrons around the spacecraft. It is a suite of detectors on the Juno Jupiter orbiter (launched 2011, orbiting Jupiter since 2016). JADE includes JADE-E, JADE-I, and the EBox. JADE-E and JADE-I are sensors that are spread out on the spacecraft, and the EBox is located inside the Juno Radiation Vault. EBox stands for Electronics Box. JADE-E is for detecting electrons from 0.1 to 100 keV, and there are three JADE-E sensors on Juno. JADE-I is for detecting ions from 5 eV to 50 keV. It is designed to return data in situ on Jupiter's auroral region and magnetospheric plasmas, by observing electrons and ions in this region. It is primarily focused on Jupiter, but it was turned on in January 2016 while still en route to study inter-planetary space (when it was still several million miles from Jupiter at that time). JADE was built by Southwest Research Institute (SwRI), located in the United States in Texas. Two other instruments help understand the magnetosphere of Jupiter, WAVES and MAG. The JEDI instrument measures higher energy ions and electrons and JADE lower energy ones; therefore they are complementary.


id: jovian-infrared-auroral-mapper-20260505-0
file: data/en.wikipedia.org/wiki/Jovian_Infrared_Auroral_Mapper-0.md
category: reference
title: Jovian Infrared Auroral Mapper
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Jovian_Infrared_Auroral_Mapper
date_saved: 2026-05-05T09:45:12.422936+00:00
instance: kb-cron
parent: jovian-infrared-auroral-mapper-20260505-0
summary:
Jovian Infrared Auroral Mapper (JIRAM) is an instrument on the Juno spacecraft in orbit of the planet Jupiter. It is an image spectrometer and was contributed by Italy. Similar instruments are on ESA Rosetta, Venus Express, and Cassini-Huygens missions. The primary goal of JIRAM is to probe the upper layers of Jupiter's atmosphere down to pressures of 5–7 bars (72–102 pound/square inch) at infrared wavelengths in the 2–5 μm interval using an imager and a spectrometer. The Jupiter's atmosphere and auroral regions are targeted for study. In particular it has been designed to study the dynamics and chemistry in the atmosphere, perhaps determining the how Jovian hot spots form. H+3 ions, ammonia, and phosphine can be mapped. The ion of Hydrogen H+3 is rare on Earth, but is one of the most common ions in the universe and known as protonated molecular hydrogen or the trihydrogen cation. Despite the intense magnetosphere of Jupiter, the JIRAM is expected to be operational for at least the first eight orbits. Previously Jupiter was observed by an Infrared imaging spectrometer called NIMS (Near-Infrared Mapping Spectrometer) on the Galileo Jupiter orbiter. JIRAM was used to observe Earth during its flyby en route to Jupiter. These


id: kepler-photometer-20260505-0
file: data/en.wikipedia.org/wiki/Kepler_photometer-0.md
category: reference
title: Kepler photometer
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Kepler_photometer
date_saved: 2026-05-05T09:45:13.590989+00:00
instance: kb-cron
parent: kepler-photometer-20260505-0
summary:
The Kepler photometer is the main instrument on NASA's Kepler space telescope. It is a Schmidt telescope (95 cm clear aperture, 140 cm mirror) with an array of 42 2200x1024 CCDs in the focal plane; each CCD is flat, but they are mounted on a curved structure to account for the curved focal plane. The CCDs are not abutting, so the focal plane is not entirely covered, but since the mission's goal is to observe a sample of stars, this doesn't matter. == References == Kepler Mission: Photometer and Spacecraft [1]


id: lara-20260505-0
file: data/en.wikipedia.org/wiki/LaRa-0.md
category: reference
title: LaRa
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/LaRa
date_saved: 2026-05-05T09:45:14.880276+00:00
instance: kb-cron
parent: lara-20260505-0
summary:
LaRa (Lander Radioscience) was a Belgian radio science experiment that will be placed onboard Kazachok, planned to be launched in 2022. LaRa will monitor the Doppler frequency shift of a radio signal traveling between the Martian lander and the Earth. These Doppler measurements will be used to precisely observe the orientation and rotation of Mars, leading to a better knowledge of the internal structure of the planet. Kazachok was cancelled, and the ExoMars mission was moved to 2028. == Instrument description == LaRa will obtain coherent two-way Doppler measurements from the X band radio link between Kazachok and large antennas on Earth, like those of the Deep space network. The relative radial velocity between the Earth and the Martian lander is inferred from Doppler shifts measured at the Earth ground stations. Masers at the Earth's ground stations ensure the frequency stability. Véronique Dehant, scientist at the Royal Observatory of Belgium, is the Principal Investigator of the experiment. Antwerp Space N.V., a subsidiary of OHB SE, is the manufacturer of the LaRa instrument. The main parts of the transponder are the coherent detector, the transmitter with the solid-state power amplifier, the micro controller unit, the receiver and the power supply unit.


id: long-lived-in-situ-solar-system-explorer-20260505-0
file: data/en.wikipedia.org/wiki/Long_Lived_In-situ_Solar_System_Explorer-0.md
category: reference
title: Long Lived In-situ Solar System Explorer
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Long_Lived_In-situ_Solar_System_Explorer
date_saved: 2026-05-05T09:45:16.047216+00:00
instance: kb-cron
parent: long-lived-in-situ-solar-system-explorer-20260505-0
summary:
Long Lived In-situ Solar System Explorer (LLISSE) is a possible NASA payload on the Russian Venera-D mission to Venus. == Overview == LLISSE uses new materials and heat-resistant electronics that would enable independent operation for about 90 Earth days. This endurance may allow it to obtain periodic measurements of weather data to update global circulation models and quantify near surface atmospheric chemistry variability. Its anticipated instruments include wind speed/direction sensors, temperature sensors, pressure sensors, and a chemical multi-sensor array. LLISSE is a small 20 cm (7.9 in) cube of about 10 kg (22 lb). The Venera-D lander may carry two LLISSE units; one would be battery-powered (3,000 h), and the other would be wind-powered. == References ==


id: lyra-20260505-0
file: data/en.wikipedia.org/wiki/LYRA-0.md
category: reference
title: LYRA
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/LYRA
date_saved: 2026-05-05T09:45:17.282783+00:00
instance: kb-cron
parent: lyra-20260505-0
summary:
LYRA (Lyman Alpha Radiometer) is the solar UV radiometer on board Proba-2, a European Space Agency technology demonstration satellite that was launched on November 2, 2009. LYRA has been designed and manufactured by a Belgian-Swiss-German consortium (ROB-SIDC, PMOD/WRC, IMOMEC, CSL, MPS and BISA) with additional international collaborations (Japan, USA, Russia, and France). Jean-François Hochedez (ROB) is Principal Investigator, Yves Stockman (CSL) is Project Manager, and Werner Schmutz (PMOD) is Lead co-Investigator. LYRA will monitor the Solar irradiance in four UV passbands. They have been chosen for their relevance to solar physics, aeronomy and Space Weather: the 115-125 nm Lyman-α channel, the 200-220 nm Herzberg continuum channel, the Aluminium filter channel (17-50 nm) including He II at 30.4 nm, and the Zirconium filter channel (1-20 nm). The Radiometric calibration of the instrument is traceable to Synchrotron source standards, Physikalisch-Technische Bundesanstalt (PTB) and National Institute of Standards and Technology (NIST). Its stability will be monitored by onboard calibration light sources (light-emitting diodes), which allow distinguishing between potential degradations of the detectors and filters. Additionally, a redundancy strategy contributes to the accuracy and the stability of the measurements. LYRA will benefit from wide bandgap detectors based on diamond: it will be the first


id: magnetometer-juno-20260505-0
file: data/en.wikipedia.org/wiki/Magnetometer_(Juno)-0.md
category: reference
title: Magnetometer (Juno)
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Magnetometer_(Juno)
date_saved: 2026-05-05T09:45:18.504639+00:00
instance: kb-cron
parent: magnetometer-juno-20260505-0
summary:
Magnetometer (MAG) is an instrument suite on the Juno orbiter for planet Jupiter. The MAG instrument includes both the Fluxgate Magnetometer (FGM) and Advanced Stellar Compass (ASC) instruments. There two sets of MAG instrument suites, and they are both positioned on the far end of three solar panel array booms. Each MAG instrument suite observes the same swath of Jupiter, and by having two sets of instruments, determining what signal is from the planet and what is from spacecraft is supported. Avoiding signals from the spacecraft is another reason MAG is placed at the end of the solar panel boom, about 10 m (33 feet) and 12 m (39 feet) away from the central body of the Juno spacecraft. The MAG instrument is designed to detect the magnetic field of Jupiter, which is one of the largest structures in the Solar System. If one could see Jupiter's magnetic field from Earth, it would appear five times larger than the full moon in the sky despite being nearly 1700 times farther away. Jupiter's internal magnetic field prevents the solar wind, a stream of ionized particles emitted by the Sun, from interacting directly with its atmosphere, and instead diverts it away from


id: mars-organic-molecule-analyser-20260505-0
file: data/en.wikipedia.org/wiki/Mars_Organic_Molecule_Analyser-0.md
category: reference
title: Mars Organic Molecule Analyser
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Mars_Organic_Molecule_Analyser
date_saved: 2026-05-05T09:45:20.894507+00:00
instance: kb-cron
parent: mars-organic-molecule-analyser-20260505-0
summary:
The Mars Organic Molecule Analyser (MOMA) is a mass spectrometer-based instrument on board the Rosalind Franklin rover to be launched in 2028 to Mars on an astrobiology mission. It will search for organic compounds (carbon-containing molecules) in the collected soil samples. By characterizing the molecular structures of detected organics, MOMA can provide insights into potential molecular biosignatures. MOMA will be able to detect organic molecules at concentrations as low as 10 parts-per-billion by weight (ppbw). MOMA examines solid crushed samples exclusively; it does not perform atmospheric analyses. The Principal Investigator is Fred Goesmann, from the Max Planck Institute for Solar System Research in Germany. == Overview == The goal of MOMA is to seek signs of past life on Mars (biosignatures) by analysing a wide range of organic compounds that may be found in drilled samples acquired from 2 meters below the Martian surface by the Rosalind Franklin rover. MOMA examines solid crushed samples only; it does not perform atmospheric analyses. MOMA will first volatilize solid organic compounds so that they can be analysed by a mass spectrometer; this volatilisation of organic material is achieved by two different techniques: laser desorption and thermal volatilisation, followed by separation using four GC-MS


id: mars-radiation-environment-experiment-20260505-0
file: data/en.wikipedia.org/wiki/Mars_Radiation_Environment_Experiment-0.md
category: reference
title: Mars Radiation Environment Experiment
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Mars_Radiation_Environment_Experiment
date_saved: 2026-05-05T09:45:22.065459+00:00
instance: kb-cron
parent: mars-radiation-environment-experiment-20260505-0
summary:
The Mars Radiation Environment Experiment (MARIE) was designed to measure the radiation environment of Mars using an energetic particle spectrometer as part of the science mission of the 2001 Mars Odyssey spacecraft (launched on April 7, 2001). It was led by NASA's Johnson Space Center and the science investigation was designed to characterize aspects of the radiation environment both on the way to Mars and while it was in the Martian orbit. Since space radiation presents an extreme hazard to crews of interplanetary missions the experiment was an attempt to predict anticipated radiation doses that would be experienced by future astronauts and it helped determine possible effects of Martian radiation on human beings. Space radiation comes from cosmic rays emitted by Earth's local star, the Sun, and from stars beyond the Solar System as well. Space radiation can trigger cancer and cause damage to the central nervous system. Similar instruments are flown on the Space Shuttles and on the International Space Station (ISS), but none have ever flown outside Earth's protective magnetosphere, which blocks much of this radiation from reaching the surface of our planet. MARIE was turned off on 28 October 2003 after communication was lost during a large


id: marsis-20260505-0
file: data/en.wikipedia.org/wiki/MARSIS-0.md
category: reference
title: MARSIS
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/MARSIS
date_saved: 2026-05-05T09:45:23.265306+00:00
instance: kb-cron
parent: marsis-20260505-0
summary:
MARSIS (Mars Advanced Radar for Subsurface and Ionosphere Sounding) is a low frequency, pulse-limited radar sounder and altimeter developed by the University of Rome La Sapienza and Alenia Spazio (today Thales Alenia Space Italy). The Italian MARSIS instrument, which is operated by the European Space Agency, is operational and orbits Mars as an instrument for the ESA's Mars Express exploration mission. The MARSIS Principal Investigator is Giovanni Picardi from the University of Rome "La Sapienza", Italy. It features ground-penetrating radar capabilities, which uses synthetic aperture technique and a secondary receiving antenna to isolate subsurface reflections. MARSIS identified buried basins on Mars. MARSIS was funded by ASI (Italy) and NASA (USA). The processor runs the real-time operating system EONIC Virtuoso. == Deployment == On May 4, 2005, Mars Express deployed the first of its two 20-metre-long radar booms for the MARSIS experiment. At first the boom didn't lock fully into place; however, exposing it to sunlight for a few minutes on May 10 fixed the glitch. The second 20 m boom was successfully deployed on June 14. Both 20 m booms were needed to create a 40 m dipole antenna for MARSIS to work; a less crucial 7-meter-long monopole antenna was


id: mass-spectrometer-for-planetary-exploration-20260505-0
file: data/en.wikipedia.org/wiki/Mass_Spectrometer_for_Planetary_Exploration-0.md
category: reference
title: Mass Spectrometer for Planetary Exploration
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Mass_Spectrometer_for_Planetary_Exploration
date_saved: 2026-05-05T09:45:24.462092+00:00
instance: kb-cron
parent: mass-spectrometer-for-planetary-exploration-20260505-0
summary:
The MAss Spectrometer for Planetary EXploration (MASPEX) is a time-of-flight mass spectrometer capable of high-resolution and high-sensitivity that allows the determination of a wide variety of chemical compounds in complex mixtures. This instrument will fly on board the planned Europa Clipper orbiter to explore Jupiter's moon Europa. This astrobiology mission will analyse the composition of Europa's surface while in orbit, and will directly assess its internal ocean habitability by flying through Europa's tenuous atmosphere. On 27 May 2016 it was announced that MASPEX was selected to fly on the mission. The instrument has also been proposed to fly on three Discovery program missions: Enceladus Life Finder (ELF), comet Hartley 2 (PRIME), and to the main belt comet Read (Proteus). It also has applications for probes, landers, and sample return missions. The original Principal Investigator was Jack Waite, and the Technical Lead is Tim Brockwell, from the Southwest Research Institute. In 2020 NASA announced that Jim Burch of Southwest Research Institute would become the Principal Investigator and that some instrument capabilities might be reduced due to technical and financial limitations. == Overview == MASPEX is a next generation spectrometer with significantly improved performance over existing instruments, that was developed over 10


id: materials-adherence-experiment-20260505-0
file: data/en.wikipedia.org/wiki/Materials_Adherence_Experiment-0.md
category: reference
title: Materials Adherence Experiment
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Materials_Adherence_Experiment
date_saved: 2026-05-05T09:45:25.685217+00:00
instance: kb-cron
parent: materials-adherence-experiment-20260505-0
summary:
The Materials Adherence Experiment (MAE) was a material science experiment conducted between July 4, 1997, and August 12, 1997, during NASA's Mars Pathfinder mission. This was a joint experiment between NASA and the Jet Propulsion Laboratory at the California Institute of Technology that consisted of a small module mounted to Pathfinder's rover Sojourner that examined the effects of Martian surface dust on solar cells. == Purpose == Using solar power on the Martian surface is challenging because the Martian atmosphere has a significant amount of dust suspended in it. In addition to blocking sunlight from reaching Mars's surface, dust particles gradually settle out of the air and onto objects. As Pathfinder was NASA's first Mars surface mission to be solar-powered, the effect of Martian dust settling on solar cells was not well understood before the mission. It was predicted at the time that dust particles in the Martian atmosphere would settle on the solar cells powering Pathfinder, blocking sunlight from striking them and slowly causing Pathfinder to lose power. Since knowing how the settling of dust out of Mars's atmosphere would affect solar cell performance would be critical to subsequent solar-powered missions on Mars, the MAE was included aboard the


id: microwave-humidity-sounder-20260505-0
file: data/en.wikipedia.org/wiki/Microwave_humidity_sounder-0.md
category: reference
title: Microwave humidity sounder
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Microwave_humidity_sounder
date_saved: 2026-05-05T09:45:26.866232+00:00
instance: kb-cron
parent: microwave-humidity-sounder-20260505-0
summary:
The Microwave Humidity Sounder (MHS) is a five-channel passive microwave radiometer, with channels from 89 to 190 GHz. It is very similar in design to the AMSU-B instrument, but some channel frequencies have been altered. It is used to study profiles of atmospheric water vapor and provide improved input data to the cloud-clearing algorithms in the IR and MW sounder suites. Instruments were launched on NOAA's POES satellite series starting with NOAA-18 launched in May 2005 and the European Space Agency's MetOp series starting with MetOp-A launched in October 2006, continuing with MetOp-B launched in September 2012 and Metop-C launched in November 2018. The follow on instrument to MHS is MWS on the Metop-SGA satellites. The Microwave Humidity Sounder was designed and developed by Astrium EU in Portsmouth, UK, under contract to EUMETSAT. == Instrument characteristics == Heritage: AMSU-B, HSB Swath: 1650 km Spatial resolution: 17 km horizontal at nadir Mass: 63 kg Duty cycle: 100% Power: 74 W (BOL) Data rate: 4.2 kbit/s Field of View: ± 49.5 degrees cross-track Instrument Instantaneous Field of View: 1.1 degrees circular Table 1: Radiometric characteristics of the MHS == References == == External links == NOAA KLM User's Guide


id: microwave-radiometer-juno-20260505-0
file: data/en.wikipedia.org/wiki/Microwave_Radiometer_(Juno)-0.md
category: reference
title: Microwave Radiometer (Juno)
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Microwave_Radiometer_(Juno)
date_saved: 2026-05-05T09:45:28.069249+00:00
instance: kb-cron
parent: microwave-radiometer-juno-20260505-0
summary:
Microwave Radiometer (MWR) is an instrument on the Juno orbiter sent to planet Jupiter. MWR is a multi-wavelength microwave radiometer for making observations of Jupiter's deep atmosphere. MWR can observe radiation from 1.37 to 50 cm in wavelength, from 600 MHz to 22 GHz in frequencies. This supports its goal of observing the previously unseen atmospheric features and chemical abundances hundreds of miles or kilometers into Jupiter's atmosphere. MWR is designed to detect six different frequencies in that range using separate antennas. MWR views Jupiter's microwave radiation so it can see up to hundreds of miles deep into the planet. In August 2016, as Juno swung closely by the planet MWR achieved a penetration of 200 to 250 miles (350 to 400 kilometers) below the surface cloud layer. MWR is designed to make observations below the cloud-tops, especially detecting the abundances of certain chemicals and determining dynamic features. These depths have not been observed before. MWR was launched aboard the Juno spacecraft on August 5, 2011 (UTC) from Cape Canaveral, USA, as part of the New Frontiers program, and after an interplanetary journey that including a swingby of Earth, entered a polar orbit of Jupiter on July 5, 2016 (UTC),


id: microwave-sounding-unit-20260505-0
file: data/en.wikipedia.org/wiki/Microwave_sounding_unit-0.md
category: reference
title: Microwave sounding unit
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Microwave_sounding_unit
date_saved: 2026-05-05T09:45:29.211966+00:00
instance: kb-cron
parent: microwave-sounding-unit-20260505-0
summary:
The microwave sounding unit (MSU) was the predecessor to the Advanced Microwave Sounding Unit (AMSU). The MSU was first launched aboard the TIROS-N satellite in late 1978 and provided global coverage (from Pole to Pole). It carries a 4-channel microwave radiometer, operating between 50 and 60 GHz. Spatial resolution on the ground was 2.5 deg in longitude and latitude (about 250 km circle). There were 9 different MSUs launched; the most recent one on NOAA-14. They provided measurements of the temperature of the troposphere and lower stratosphere until 1998, when the first AMSU was deployed. AMSU provides many more channels and finer resolution (about 50 km). Table 1 lists some characteristics of the MSU. The radiometer's antenna scans underneath the satellite through nadir, and its polarization vector rotates with the scan angle. In the table, "vertical polarization near nadir" means that the E-vector is parallel to the scan direction at nadir, and "horizontal polarization" means the orthogonal direction. Table 1 Radiometric characteristics of the Microwave Sounding Unit == Applications == The MSU was used by NOAA for meteorological analyses in combination with two infrared instruments, and sometimes alone, for post-analysis of weather events and other atmospheric phenomena such as waves.


id: mimos-ii-20260505-0
file: data/en.wikipedia.org/wiki/MIMOS_II-0.md
category: reference
title: MIMOS II
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/MIMOS_II
date_saved: 2026-05-05T09:45:30.407890+00:00
instance: kb-cron
parent: mimos-ii-20260505-0
summary:
MIMOS II is the miniaturised Mössbauer spectrometer, developed by Dr. Göstar Klingelhöfer at the Johannes Gutenberg University in Mainz, Germany, that is used on the Mars Exploration Rovers Spirit and Opportunity for close-up investigations on the Martian surface of the mineralogy of iron-bearing rocks and soils. MIMOS II uses a Cobalt-57 gamma ray source of about 300 mCi at launch which gave a 6-12 hr time for acquisition of a standard MB spectrum during the primary mission on Mars, depending on total Fe content and which Fe-bearing phases are present. Cobalt-57 has a half-life of only 271.8 days (h The MIMOS II sensorheads used snMars are approx 9 cm x 5 cm x 4 cm and weigh about 400g. The MIMOS II system also includes a circuit board of about 100g. == References ==


id: mini-tes-20260505-0
file: data/en.wikipedia.org/wiki/Mini-TES-0.md
category: reference
title: Mini-TES
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Mini-TES
date_saved: 2026-05-05T09:45:31.559953+00:00
instance: kb-cron
parent: mini-tes-20260505-0
summary:
The Miniature Thermal Emission Spectrometer (Mini-TES) is an infrared spectrometer used for detecting the composition of a material (typically rocks) from a distance. By making its measurements in the thermal infrared part of the electromagnetic spectrum, it has the ability to penetrate through the dust coatings common to the Martian surface which is usually problematic for remote sensing observations. There is one on each of the two Mars Exploration Rovers. == Development == The Mini-TES was originally developed by Raytheon for the Department of Geological Sciences at Arizona State University. The Mini-TES is a miniaturized version of Raytheon's Mars Global Surveyor (MGS) TES, built by Arizona State University and Raytheon SAS’ Santa Barbara Remote Sensing. The MGS TES data helped scientists choose landing sites for the Spirit and Opportunity Mars explorer rovers. == Martian soil == The Mini-TES is used for identifying promising rocks and soils for closer examination, and to determine the processes that formed Martian rocks. It measures the infrared radiation that the target rock or object emits in 167 different wavelengths, providing information about the target's composition. One particular goal is to search for minerals that were formed by the action of water, such as carbonates and


id: modular-optoelectronic-multispectral-scanner-20260505-0
file: data/en.wikipedia.org/wiki/Modular_optoelectronic_multispectral_scanner-0.md
category: reference
title: Modular optoelectronic multispectral scanner
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Modular_optoelectronic_multispectral_scanner
date_saved: 2026-05-05T09:45:32.762948+00:00
instance: kb-cron
parent: modular-optoelectronic-multispectral-scanner-20260505-0
summary:
The modular optoelectronic multispectral scanner (MOMS) is a scanning system for spaceborne, geoscientific remote sensing applications used in satellite navigation systems for sensing atmospheric and oceanic systems. The scanner is combination of separate spectrometer blocks. == History == The modular optoelectronic multispectral scanner is an optical technology programme funded by the German Ministry for Research and Technology. It was jointly designed and developed by DLR, LMU and EADS Astrium. == Characteristics == The modular structure of MOMS makes it suitable for use in wide variety of geo-spatial missions, the modules being sensor, optical lens, electronics and filters. The first flight of MOMS yielded high-resolution images with 20x20 m ground pixel size from about 300 km orbital altitude. === MOMS-01 === MOMS01 consists of five instruments mounted on a carbon-fiber structure: The optical module with four objectives, eight arrays, and associated shutters. Each module represents one spectral band, consisted of filters, dual-lens optics, four CCD detector line-scanning arrays, and preamplifier electronics. A power box for overall power control. A logic box for all sensor function control (including real-time correction, and formatting of the source data stream from the optical module) A HDDT (high-density digital tape) recorder. A pressurized container for the


id: moonlight-20260505-0
file: data/en.wikipedia.org/wiki/MoonLIGHT-0.md
category: reference
title: MoonLIGHT
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/MoonLIGHT
date_saved: 2026-05-05T09:45:33.985632+00:00
instance: kb-cron
parent: moonlight-20260505-0
summary:
MoonLIGHT (Moon Laser Instrumentation for General relativity High accuracy Tests) is a laser retroreflector developed as a collaboration primarily between the University of Maryland in the United States, and the Italian National Institute for Nuclear Physics - National Laboratories of Frascati (INFN-LNF) to complement and expand on the Lunar Laser Ranging experiment started with the Apollo Program in 1969. MoonLIGHT was planned to be launched in July 2020 as a secondary payload on the MX-1E lunar lander built by the private company Moon Express. However, the launch of the MX-1E has been cancelled. In 2018 INFN proposed to the European Space Agency (ESA) the MoonLIGHT Pointing Actuators (MPAc) project and was contracted by ESA to deliver it. MPAc is an INFN development for ESA, with auxiliary support by the Italian Space Agency (ASI) for prototyping work. In 2021, ESA agreed with NASA to launch MPAc with a Commercial Lunar Payload Services (CLPS) mission. Nova-C, the lander on which MPAc will be integrated, is designed by Intuitive Machines and the landing site is Reiner Gamma. The expected launch date of the Nova-C mission carrying the instrument, IM-3, is in 2026. == Overview == Laser Ranging is a technique used to perform


id: mssta-20260505-0
file: data/en.wikipedia.org/wiki/MSSTA-0.md
category: reference
title: MSSTA
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/MSSTA
date_saved: 2026-05-05T09:45:35.207408+00:00
instance: kb-cron
parent: mssta-20260505-0
summary:
The Multi-Spectral Solar Telescope Array (MSSTA) was a sounding rocket payload built by Arthur B. C. Walker Jr. at Stanford University in the 1990s to test EUV/XUV imaging of the Sun using normal incidence EUV-reflective multilayer optics. == History == MSSTA contained a large number of individual telescopes (> 10), all trained on the Sun and all sensitive to slightly different wavelengths of ultraviolet light. Like all sounding rockets, MSSTA flew for approximately 14 minutes per mission, about 5 minutes of which were in space—just enough time to test a new technology or yield "first results" science. MSSTA is one of the last solar observing instruments to use photographic film rather than a digital camera system such as a CCD. MSSTA used film instead of a CCD in order to achieve the highest possible spatial resolution and to avoid the electronics difficulty presented by the large number of detectors that would have been required for its many telescopes. MSSTA and its sister rocket, NIXT, were prototypes for normal incidence extreme ultraviolet imaging telescopes that are in use today, as well as the historic EIT instrument aboard the SOHO spacecraft, and the TRACE spacecraft. MSSTA flew three times: once in 1991


id: multi-angle-imaging-spectroradiometer-20260505-0
file: data/en.wikipedia.org/wiki/Multi-angle_imaging_spectroradiometer-0.md
category: reference
title: Multi-angle imaging spectroradiometer
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Multi-angle_imaging_spectroradiometer
date_saved: 2026-05-05T09:45:36.352254+00:00
instance: kb-cron
parent: multi-angle-imaging-spectroradiometer-20260505-0
summary:
The multi-angle imaging spectroradiometer (MISR) is a scientific instrument on the Terra satellite launched by NASA on 18 December 1999. This device is designed to measure the intensity of solar radiation reflected by the Earth system (planetary surface and atmosphere) in various directions and spectral bands; it became operational in February 2000. Data generated by this sensor have been proven useful in a variety of applications including atmospheric sciences, climatology and monitoring terrestrial processes. The MISR instrument consists of an innovative configuration of nine separate digital cameras that gather data in four different spectral bands of the solar spectrum. One camera points toward the nadir, while the others provide forward and aftward view angles at 26.1°, 45.6°, 60.0°, and 70.5°. As the instrument flies overhead, each region of the Earth's surface is successively imaged by all nine cameras in each of four wavelengths (blue, green, red, and near-infrared). The data gathered by MISR are useful in climatological studies concerning the disposition of the solar radiation flux in the Earth's system. MISR is specifically designed to monitor the monthly, seasonal, and long-term trends of atmospheric aerosol particle concentrations including those formed by natural sources and by human activities, upper air winds


id: nadir-and-occultation-for-mars-discovery-20260505-0
file: data/en.wikipedia.org/wiki/Nadir_and_Occultation_for_Mars_Discovery-0.md
category: reference
title: Nadir and Occultation for Mars Discovery
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Nadir_and_Occultation_for_Mars_Discovery
date_saved: 2026-05-05T09:45:37.538199+00:00
instance: kb-cron
parent: nadir-and-occultation-for-mars-discovery-20260505-0
summary:
Nadir and Occultation for MArs Discovery (NOMAD) is a 3-channel spectrometer on board the ExoMars Trace Gas Orbiter (TGO) launched to Mars orbit on 14 March 2016. NOMAD is designed to perform high-sensitivity orbital identification of atmospheric components, concentration and temperature, their sources, loss, and cycles. It measures the sunlight reflected from the surface and atmosphere of Mars, and it analyses its wavelength spectrum to identify the components of the Martian atmosphere that may suggest a biological source. The Principal Investigator is Ann Carine Vandaele, from the Belgian Institute for Space Aeronomy, Belgium. == Overview == NOMAD is one of four science instruments on board the European ExoMars TGO orbiter. This spectrometer consists of three separate channels: solar occultation (SO), limb nadir and occultation (LNO), and ultraviolet and visible spectrometer (UVIS). The first two channels work in the infrared (2.2 to 4.3 μm); the third channel (UVIS) works in the UV-visible range (0.2 to 0.65 μm), which is able to measure ozone, sulphuric acid, and perform aerosol studies. Measurements are carried out during solar occultation, i.e. the instrument points toward the sunset as the orbiter moves toward or away the dark side of Mars. It also measures in nadir mode,


id: navcam-20260505-0
file: data/en.wikipedia.org/wiki/Navcam-0.md
category: reference
title: Navcam
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Navcam
date_saved: 2026-05-05T09:45:38.703648+00:00
instance: kb-cron
parent: navcam-20260505-0
summary:
Navcam, short for navigational camera, is a type of camera found on certain robotic rovers or spacecraft used for navigation without interfering with scientific instruments. Navcams typically take wide angle photographs that are used to plan the next moves of the vehicle or object tracking. == Overview == The Mars Curiosity rover has two pairs of black and white navigation cameras mounted on the mast to support ground navigation. The cameras have a 45 degree angle of view and use visible light to capture stereoscopic 3-D imagery. These cameras, like those on the Mars Pathfinder missions support use of the ICER image compression format. European Space Agency Rosetta spacecraft used a single camera with 5 degree field of view and 12 bit 1024x1024px resolution allowing for visual tracking on each of spacecraft approaches to the asteroids and finally the comet. == Gallery == == See also == Astrionics Hazard avoidance camera (Hazcam) Panoramic camera (Pancam) Optical, Spectroscopic, and Infrared camera OSIRIS List of NASA cameras on spacecraft Mars rover == References ==


id: odin-osiris-20260505-0
file: data/en.wikipedia.org/wiki/Odin-OSIRIS-0.md
category: reference
title: Odin-OSIRIS
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Odin-OSIRIS
date_saved: 2026-05-05T09:45:41.000273+00:00
instance: kb-cron
parent: odin-osiris-20260505-0
summary:
OSIRIS (Optical Spectrograph and InfraRed Imager System) is an instrument that measures vertical profiles of spectrally dispersed, limb scattered sunlight from the upper troposphere into the lower mesosphere. OSIRIS is one of two instruments on the Odin satellite, launched February, 2001 (the other instrument being a sub-mm radiometer) into a Sun-synchronous, 6 pm/6 am local time orbit at 600 km. This restricts OSIRIS sunlit observations to the Northern hemisphere in May, June, July and August, and the Southern hemisphere in November, December, January and February. Global coverage from 82°S to 82°N occurs on the months adjoining the equinoxes. OSIRIS measurements began November, 2001 and continue to the present. == Objectives == Stratospheric ozone science: To elucidate the geographical extent of, and mechanisms responsible for, ozone depletion in the "ozone hole" region and to study dilution effects and possible heterogeneous chemistry even outside of the polar regions due to sulphate aerosols. Coupling of atmospheric regions: To study some of the mechanisms that provide coupling between the upper and lower atmosphere, e.g., downward transport of NO with its effects on ozone photochemistry and the vertical exchange of minor species such as odd oxygen, CO, and H2O. == Instrument == The OSIRIS spectrograph


id: optical-payload-for-lasercomm-science-20260505-0
file: data/en.wikipedia.org/wiki/Optical_Payload_for_Lasercomm_Science-0.md
category: reference
title: Optical Payload for Lasercomm Science
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Optical_Payload_for_Lasercomm_Science
date_saved: 2026-05-05T09:45:42.173012+00:00
instance: kb-cron
parent: optical-payload-for-lasercomm-science-20260505-0
summary:
Optical PAyload for Lasercomm Science (OPALS) is a spacecraft communication instrument developed at the Jet Propulsion Laboratory that was tested on the International Space Station (ISS) from 18 April 2014 to 17 July 2014 to demonstrate the technology for laser communications systems between spacecraft and ground stations. The purpose of OPALS is to do research into replacing traditional radio-frequency (RF) communications which are currently used on spacecraft. This will allow spacecraft to increase the rate at which data is downlinked by 10 to 100 times. It also will have less error than RF communication. It launched from Cape Canaveral to the ISS on 18 April 2014 on a Falcon 9 SpaceX CRS-3 Dragon capsule resupply. The experiment used commercial products rather than space qualified components. == Science objectives == The goal of the OPALS mission was to demonstrate a downlink of a short video from space using laser communication. In doing so, the following was studied: Maintenance of an optical link between the ground and space with various environmental and operational conditions Processing of distorted data Procedure design for setting up the optical link What equipment is used for sending and receiving signal == Mission architecture == Communications and commands


id: orbiting-carbon-observatory-3-20260505-0
file: data/en.wikipedia.org/wiki/Orbiting_Carbon_Observatory_3-0.md
category: reference
title: Orbiting Carbon Observatory 3
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Orbiting_Carbon_Observatory_3
date_saved: 2026-05-05T09:45:43.336222+00:00
instance: kb-cron
parent: orbiting-carbon-observatory-3-20260505-0
summary:
The Orbiting Carbon Observatory-3 (OCO-3) is a NASA-JPL instrument designed to measure carbon dioxide in Earth's atmosphere. The instrument is mounted on the Japanese Experiment Module-Exposed Facility on board the International Space Station (ISS). OCO-3 was launched as part of CRS-17 on 4 May 2019 at 06:48 UTC. The nominal mission lifetime is ten years. OCO-3 was assembled using spare materials from the Orbiting Carbon Observatory-2 satellite. Because the OCO-3 instrument is similar to the OCO-2 instrument, it is expected to have similar performance with its measurements used to quantify CO2 to 1 ppm precision or better at 3 Hz. == History and timeline == 24 February 2009 - Orbiting Carbon Observatory was launched on a Taurus XL rocket but failed to achieve orbit when the fairing failed to separate from the satellite. 1 February 2010 - The 2010 President's budget included funding for development and re-flight of an OCO replacement. October 2010 - The Orbiting Carbon Observatory-2 project went into implementation phase. 2 July 2014 - OCO-2 was successfully launched from Vandenberg Air Force Base with a Delta II rocket. 2015 - Funding for the OCO-3 project cancelled. 22 December 2015 - OCO-3 project authorized to proceed. Funding was


id: planetary-fourier-spectrometer-20260505-0
file: data/en.wikipedia.org/wiki/Planetary_Fourier_Spectrometer-0.md
category: reference
title: Planetary Fourier Spectrometer
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Planetary_Fourier_Spectrometer
date_saved: 2026-05-05T09:45:44.525581+00:00
instance: kb-cron
parent: planetary-fourier-spectrometer-20260505-0
summary:
The Planetary Fourier Spectrometer (PFS) is an infrared spectrometer built by the Istituto Nazionale di Astrofisica (Italian National Institute for Astrophysics) along with the Istituto di Fisica dello spazio Interplanetario and the Consiglio Nazionale delle Ricerche (Italian National Research Council). The instrument is currently used by the European Space Agency on both the Mars Express Mission and the Venus Express Mission. It consists of four units which together weigh around 31.4 kg, including a pointing device, a power supply, a control unit, and an interferometer with electronics. The main objective of the instrument is to provide temperature profiles of Mars's carbon dioxide atmosphere, and to the study composition of the planet's atmosphere through the infrared radiation that is reflected and emitted by the planet. == Methane in the Martian atmosphere == In March 2004, Professor Vittorio Formisano, the researcher in charge of the Mars Express Planetary Fourier Spectrometer, announced the discovery of methane in the Martian atmosphere. However, methane cannot persist in the Martian atmosphere for more than a few hundred years since it can be broken down by sunlight. Thus, this discovery suggests that the methane is being continually replenished by some unidentified volcanic or geologic process, or that


id: plasma-instrument-for-magnetic-sounding-20260505-0
file: data/en.wikipedia.org/wiki/Plasma_Instrument_for_Magnetic_Sounding-0.md
category: reference
title: Plasma Instrument for Magnetic Sounding
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Plasma_Instrument_for_Magnetic_Sounding
date_saved: 2026-05-05T09:45:45.712227+00:00
instance: kb-cron
parent: plasma-instrument-for-magnetic-sounding-20260505-0
summary:
The Plasma Instrument for Magnetic Sounding (PIMS) is a Faraday cup based instrument that will fly on board the Europa Clipper orbiter to explore Jupiter's moon Europa. PIMS will measure the plasma that populates Jupiter's magnetosphere and Europa's ionosphere. The principal investigator is Dr. Adrienn Luspay-Kuti, from the Johns Hopkins University Applied Physics Laboratory (APL). == Overview == The plasma in Jupiter's magnetosphere interacts with Europa's atmosphere. This interaction results in magnetic field perturbations. While understanding this plasma interaction is inherently interesting, it is also crucial for successful magnetic sounding Europa's subsurface ocean. The interaction of the Jovian magnetic field with Europa's subsurface ocean produces a magnetic induction signature that is used to determine the ice shell thickness, ocean depth, and ocean salinity of Europa's subsurface ocean. Separating the sources of magnetic field perturbations produces a better understanding of the ocean's properties. The Plasma Instrument for Magnetic Sounding (PIMS) is a Faraday cup-based instrument that will measure the plasma of Jupiter's magnetosphere and Europa's ionosphere. Such devices on spacecraft date back to Explorer 10 in 1961 and were used by the Voyager 1 spacecraft to study Jupiter's magnetosphere in 1979. == Science goals == The three science goals of PIMS


id: plasma-wave-instrument-20260505-0
file: data/en.wikipedia.org/wiki/Plasma_wave_instrument-0.md
category: reference
title: Plasma wave instrument
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Plasma_wave_instrument
date_saved: 2026-05-05T09:45:46.896589+00:00
instance: kb-cron
parent: plasma-wave-instrument-20260505-0
summary:
A plasma wave instrument (PWI), also known as a plasma wave receiver, is a device capable of detecting vibrations in outer space plasma and transforming them into audible sound waves or air vibrations that can be heard by the human ear. This instrument was pioneered by then-University of Iowa physics professor, Donald Gurnett. Plasma wave instruments are commonly employed on space probes such as GEOTAIL, Polar, Voyager I and II (see Plasma Wave Subsystem), and Cassini–Huygens. == Operating principle == Vibrations in the audible frequency range are perceived by humans when air vibrates against their eardrum. Air, or some other vibrating medium such as water, is essential for sound perception by the human ear. Without a medium to transmit it, the sound produced by a source will not be heard by a human. There is no air in outer space, nor is there any other type of medium capable of transmitting vibrations from a source to a human ear. However, there are sources in outer space that vibrate at frequencies audible to humans if only there were some transmitting medium to carry those vibrations from the source to a human eardrum. One such source capable of vibrating at audible frequencies


id: plasma-wave-subsystem-20260505-0
file: data/en.wikipedia.org/wiki/Plasma_Wave_Subsystem-0.md
category: reference
title: Plasma Wave Subsystem
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Plasma_Wave_Subsystem
date_saved: 2026-05-05T09:45:48.115930+00:00
instance: kb-cron
parent: plasma-wave-subsystem-20260505-0
summary:
Plasma Wave Subsystem (sometimes called Plasma Wave System), abbreviated PWS, is an instrument that is on board the Voyager 1 and Voyager 2 unmanned probes of the Voyager program. The device is 16 channel step frequency receiver and a low-frequency waveform receiver that can measure electron density. The PWS uses the two long antenna in a V-shape on the spacecraft, which are also used by another instrument on the spacecraft. The instrument recorded data about the Solar System's gas giants, and about the outer reaches of the Heliosphere, and beyond. In the 2010s, the PWS was used to play the "sounds of interstellar space" as the spacecraft can sample the local interstellar medium after they departed the Sun's heliosphere. The heliosphere is a region essentially under the influence of the Sun's solar wind, rather than the local interstellar environment, and is another way of understanding the Solar System in comparison to the objects gravitationally bound (e.g in orbit) around Earth's Sun. The PWS instrument plan was introduced in 1974 during the development of the Voyager program. It was hoped it would help increase understanding of wave particle interactions and record data on the magnetospheres of planets like Jupiter and Saturn.


id: pluto-energetic-particle-spectrometer-science-investigation-20260505-0
file: data/en.wikipedia.org/wiki/Pluto_Energetic_Particle_Spectrometer_Science_Investigation-0.md
category: reference
title: Pluto Energetic Particle Spectrometer Science Investigation
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Pluto_Energetic_Particle_Spectrometer_Science_Investigation
date_saved: 2026-05-05T09:45:49.355754+00:00
instance: kb-cron
parent: pluto-energetic-particle-spectrometer-science-investigation-20260505-0
summary:
Pluto Energetic Particle Spectrometer Science Investigation (PEPSSI), is an instrument on the New Horizons space probe to Pluto and beyond, it is designed to measure ions and electrons. Specifically, it is focused on measuring ions escaping from the atmosphere of Pluto during the 2015 flyby. It is one of seven major scientific instruments aboard the spacecraft. The spacecraft was launched in 2006, flew by Jupiter the following year, and went on to flyby Pluto in 2015 where PEPSSI was able to record and transmit back to Earth its planned data collections. PEPSSI is designed to help understand the rate of atmospheric loss from the atmosphere of Pluto into space, which is thought experience comet-like atmosphere loss into outer space. These ions blend in with the surrounding solar wind which passed by Pluto. During the flyby PEPSSI sent data back to Earth every day. During the journey to Pluto, PEPSSI was also used to record data about the interplanetary medium. Data about Jupiter and its magnetotail was also collected by PEPSSI during its 2007 flyby of that planet. Beyond Pluto and into the Kuiper belt, PEPSSI can be used to study how the solar wind interacts with interstellar wind, adding to


id: radar-for-europa-assessment-and-sounding-ocean-to-near-surface-20260505-0
file: data/en.wikipedia.org/wiki/Radar_for_Europa_Assessment_and_Sounding:_Ocean_to_Near-surface-0.md
category: reference
title: Radar for Europa Assessment and Sounding: Ocean to Near-surface
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Radar_for_Europa_Assessment_and_Sounding:_Ocean_to_Near-surface
date_saved: 2026-05-05T09:45:50.531916+00:00
instance: kb-cron
parent: radar-for-europa-assessment-and-sounding-ocean-to-near-surface-20260505-0
summary:
The Radar for Europa Assessment and Sounding: Ocean to Near-surface (REASON) is a multi-frequency, multi-channel ice penetrating radar system that will be flown on board the Europa Clipper mission to Jupiter's moon Europa. REASON investigation will provide the first direct measurements of Europa's ice shell surface character and subsurface structure. == Overview == The REASON instrument makes innovative use of radar sounding, altimetry, reflectometry, plasma and particles analyses. These investigations will use a dual-frequency radar emitting HF (9 MHz) and VHF (60 MHz) with concurrent shallow and deep sounding. Both VHF and HF radiating elements are mounted on a single boom, reducing antenna mass. The mission plan also includes using REASON as a nadir altimeter capable of measuring tides to test ice shell and ocean hypotheses as well as characterizing roughness across the surface to identify potential landing sites for a future Europa Lander. The REASON instrument will also be able to spot pockets of water within the ice shell that could serve as a passageway for chemicals on the moon's surface to the ocean below — an environment where life could potentially develop. The instrument was developed by the Jackson School of Geosciences, and its Principal Investigator is Donald


id: radio-science-subsystem-20260505-0
file: data/en.wikipedia.org/wiki/Radio_science_subsystem-0.md
category: reference
title: Radio science subsystem
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Radio_science_subsystem
date_saved: 2026-05-05T09:45:51.728266+00:00
instance: kb-cron
parent: radio-science-subsystem-20260505-0
summary:
A radio science subsystem (RSS) is a subsystem placed on board a spacecraft for radio science purposes. == Function of the RSS == The RSS uses radio signals to probe a medium such as a planetary atmosphere. The spacecraft transmits a highly stable signal to ground stations, receives such a signal from ground stations, or both. Since the transmitted signal parameters are accurately known to the receiver, any changes to these parameters are attributable to the propagation medium or to the relative motion of the spacecraft and ground station. The RSS is usually not a separate instrument; its functions are usually "piggybacked" on the existing telecommunications subsystem. More advanced systems use multiple antennas with orthogonal polarizations. == Applications == Radio science is commonly used to determine the gravity field of a moon or planet by observing Doppler shift. This requires a highly stable oscillator on the spacecraft, or more commonly a "2-way coherent" transponder that phase locks the transmitted signal frequency to a rational multiple of a received uplink signal that usually also carries spacecraft commands. Another common radio science observation is in radio occultation, performed as a spacecraft is occulted by a planetary body. As the spacecraft moves behind


id: ralph-new-horizons-20260505-0
file: data/en.wikipedia.org/wiki/Ralph_(New_Horizons)-0.md
category: reference
title: Ralph (New Horizons)
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Ralph_(New_Horizons)
date_saved: 2026-05-05T09:45:52.956371+00:00
instance: kb-cron
parent: ralph-new-horizons-20260505-0
summary:
Ralph is a science instrument aboard the robotic New Horizons spacecraft, which was launched in 2006. Ralph is a visible and infrared imager and spectrometer to provide maps of relevant astronomical targets based on data from that hardware. Ralph has two major subinstruments, LEISA and MVIC. MVIC stands for Multispectral Visible Imaging Camera and is a color imaging device, while LEISA originally stood for Linear Etalon Imaging Spectral Array and is an infrared imaging spectrometer for spaceflight. LEISA observes 250 discrete wavelengths of infrared light from 1.25 to 2.5 micrometers. MVIC is a pushbroom scanner type of design with seven channels, including red, blue, near-infrared (NIR), and methane. == Overview == Ralph is one of seven major instruments aboard New Horizons which was launched in 2006 and flew by the dwarf planet Pluto in 2015. At Pluto, Ralph enables the observation of many aspects including: geology of Pluto form structure surface composition surface temperature Ralph and Alice were used to characterize the atmosphere of Pluto in 2015. Ralph was previously used to observe the planet Jupiter and its moons in 2006 and in 2007 when it flew-by en route out of the Solar System and past Pluto. Observations of Jupiter


id: raman-laser-spectrometer-20260505-0
file: data/en.wikipedia.org/wiki/Raman_Laser_Spectrometer-0.md
category: reference
title: Raman Laser Spectrometer
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Raman_Laser_Spectrometer
date_saved: 2026-05-05T09:45:54.156293+00:00
instance: kb-cron
parent: raman-laser-spectrometer-20260505-0
summary:
Raman Laser Spectrometer (RLS) is a miniature Raman spectrometer that is part of the science payload on board the European Space Agency's Rosalind Franklin rover, tasked to search for biosignatures and biomarkers on Mars. The rover is planned to be launched not earlier than 2028 and land on Mars in 2029. Raman spectroscopy is a technique employed to identify mineral phases produced by water-related processes. RLS will help to identify organic compounds and search for microbial life by identifying the mineral products and indicators of biologic activities. RLS will provide geological and mineralogical context information that will be scientifically cross-correlated with that obtained by other instruments. == Overview == Raman spectroscopy is sensitive to the composition and structure of any organic compound, making it a powerful tool for the definitive identification and characterisation of biomarkers, and providing direct information of potential biosignatures of past microbial life on Mars. This instrument will also provide general mineralogical information for igneous, metamorphous, and sedimentary processes. RST will also correlate its spectral information with other spectroscopic and imaging instruments such as the Infrared Spectrometer and MicrOmega-IR. This will be the first Raman analyser to be deployed for a planetary exploration. The first version for


id: reentry-breakup-recorder-20260505-0
file: data/en.wikipedia.org/wiki/Reentry_Breakup_Recorder-0.md
category: reference
title: Reentry Breakup Recorder
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Reentry_Breakup_Recorder
date_saved: 2026-05-05T09:45:55.347164+00:00
instance: kb-cron
parent: reentry-breakup-recorder-20260505-0
summary:
A Reentry Breakup Recorder (REBR) is a device that is designed to be placed aboard a spacecraft to record pertinent data when the spacecraft (intentionally) breaks up as it re-enters Earth's atmosphere. The device records data regarding the thermal, acceleration, rotational and other stresses the vehicle is subject to. In the final stages it transmits the data back to a laboratory before it is destroyed when it hits the surface. == History == Two REBRs were launched in January 2011 on the Japanese Kounotori 2 transfer vehicle. One recorded the subsequent re-entry of that vehicle, and the other was placed aboard the Johannes Kepler ATV, which reentered Earth's atmosphere on 21 June 2011. The Kounotori 2 vehicle re-entered on 30 March 2011. Its REBR successfully collected and returned its data; it survived the impact with the ocean and while floating continued to transmit. It took between 6 and 8 weeks to analyze the data. The second unit was intended to collect data during the reentry of the Johannes Kepler ATV (ATV-2); however the device failed to make contact after reentry and consequently no data was retrieved. Two other units were used successfully for Kounotori 3 for its reentry on September


id: rex-new-horizons-20260505-0
file: data/en.wikipedia.org/wiki/REX_(New_Horizons)-0.md
category: reference
title: REX (New Horizons)
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/REX_(New_Horizons)
date_saved: 2026-05-05T09:45:56.561398+00:00
instance: kb-cron
parent: rex-new-horizons-20260505-0
summary:
REX or Radio Science Experiment is an experiment on the New Horizons space probe to measure properties of the atmosphere of Pluto during the 2015 flyby. == Experiment == Experiment was designed with several goals including determination of pressure and temperature of Plutonian atmosphere, measurements of a possible ionosphere of Pluto and Charon, recording thermal emission temperatures, and taking more accurate chord lengths of Charon and Pluto. To accomplish the goals, as the spacecraft passed by Pluto, it was placed on a path that took it behind the dwarf planet in relation to the Earth, where radio signals from the flyby spacecraft passed through its atmosphere allowing various properties to be determined. REX also took measurements of the atmospheric conditions at Pluto's moon Charon as part of the mission. REX uses an ultrastable oscillator, various electronics, and radio hardware aboard the New Horizons spacecraft. REX uses the X-band radio uplink on the spacecraft. REX hardware weighs 160g (0.16 kg) and consumes 1.6 watts of spacecraft electrical power. It also makes use of other NH hardware, overall key hardware components for REX include: high-gain antenna low-noise X-band receiver ultrastable oscillator To take the measurements, REX communicates with the Deep Space Network


id: rock-abrasion-tool-20260505-0
file: data/en.wikipedia.org/wiki/Rock_Abrasion_Tool-0.md
category: reference
title: Rock Abrasion Tool
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Rock_Abrasion_Tool
date_saved: 2026-05-05T09:45:57.773704+00:00
instance: kb-cron
parent: rock-abrasion-tool-20260505-0
summary:
The Rock Abrasion Tool (RAT) is a grinding and brushing installation on NASA’s twin Mars Exploration Rovers, Spirit (MER-A) and Opportunity (MER-B), which landed on Mars in January 2004. It was designed, developed and continues to be operated by Honeybee Robotics LTD, a developer of specialized robots, automated technologies and related systems. The RAT was the first machine to gain access to the interior of rocks on another planet. The RAT has a mass of 0.685 kilograms (1.51 pounds), is 7 cm (3 in) in diameter and 10 cm (3.9 in) long, about the size of a soda can. It uses a diamond dust and resin wheel spinning at 3000 rpm to drill a 45 mm diameter by 5 mm deep bore hole in martian rocks. The RAT then uses two brushes to sweep dust from the bore holes for closer scientific inspection. Its average power consumption is 30 watts. There are five other instruments aboard both rovers, these are the Pancam (a camera), Mini-TES (an infrared spectrometer) for sensing targets at a distance, a microscopic imager, a Mössbauer spectrometer and an alpha particle X-ray spectrometer. The RAT provides these instruments with a smooth, clean surface from which they make


id: rotation-and-interior-structure-experiment-20260505-0
file: data/en.wikipedia.org/wiki/Rotation_and_Interior_Structure_Experiment-0.md
category: reference
title: Rotation and Interior Structure Experiment
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Rotation_and_Interior_Structure_Experiment
date_saved: 2026-05-05T09:45:58.982975+00:00
instance: kb-cron
parent: rotation-and-interior-structure-experiment-20260505-0
summary:
Rotation and Interior Structure Experiment (RISE) is a radio science experiment onboard InSight Mars lander that will use the spacecraft communication system to provide precise measurements of Mars' rotation and wobble. RISE precisely tracks the location of the lander to measure how much Mars's axis wobbles as it orbits the Sun. These observations will provide new constraints on the core radius and help determine whether the core of Mars is mostly liquid, and which other elements, besides iron, may be present. This study will also help scientists understand why Mars's magnetic field is so weak, as compared to Earth's. The mission launched on 5 May 2018 and landed on the surface of Mars at Elysium Planitia on 26 November 2018. == Overview == The Principal Investigator for RISE is William Folkner of JPL, who led the 1997 investigation of Mars's core using the radio link between Earth and NASA's Mars Pathfinder. RISE uses the spacecraft's radio connection with Earth to assess perturbations of Mars's rotation axis to within 10 centimeters. These measurements can provide information about the size and composition of Mars's core. The radio science equipment is largely the same as used for the Mars Exploration Rover mission, and


id: sbuv-2-20260505-0
file: data/en.wikipedia.org/wiki/SBUV/2-0.md
category: reference
title: SBUV/2
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/SBUV/2
date_saved: 2026-05-05T09:46:00.154245+00:00
instance: kb-cron
parent: sbuv-2-20260505-0
summary:
The Solar Backscatter Ultraviolet Radiometer, or SBUV/2, is a series of operational remote sensors on NOAA weather satellites in Sun-synchronous orbits which have been providing global measurements of stratospheric total ozone, as well as ozone profiles, since March 1985. The SBUV/2 instruments were developed from the SBUV experiment flown on the Nimbus-7 spacecraft which improved on the design of the original BUV instrument on Nimbus-4. These are nadir viewing radiometric instruments operating at mid to near UV wavelengths. SBUV/2 data sets overlap with data from SBUV and TOMS instruments on the Nimbus-7 spacecraft. These extensive data sets (January 1979 to the present) measure the density and vertical distribution of ozone in the Earth's atmosphere from six to 30 miles. SBUV/2 looks down at the Earth's atmosphere and the reflected sunlight at wavelengths characteristic of ozone. The SBUV/2 wavelength "channels" range from 252 nanometer (nm) to 340 nm. Ozone is measured as a ratio of sunlight incident on the atmosphere to the amount of sunlight scattered back into space. From this information, the total ozone between the instrument and the ground can be calculated. The SBUV/2 measures solar irradiance and Earth radiance (backscattered solar energy) in the near ultraviolet spectrum (160


id: seismic-experiment-for-interior-structure-20260505-0
file: data/en.wikipedia.org/wiki/Seismic_Experiment_for_Interior_Structure-0.md
category: reference
title: Seismic Experiment for Interior Structure
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Seismic_Experiment_for_Interior_Structure
date_saved: 2026-05-05T09:46:01.421738+00:00
instance: kb-cron
parent: seismic-experiment-for-interior-structure-20260505-0
summary:
The Seismic Experiment for Interior Structure (SEIS) is a seismometer and the primary scientific instrument on board the InSight Mars lander launched on 5 May 2018 for a landing on 26 November 2018; the instrument was deployed to the surface of Mars on 19 December. SEIS is expected to provide seismic measurements of marsquakes, enabling researchers to develop 3D structure maps of the deep interior. Better understanding the internal structure of Mars will lead to better understanding of the Earth, Moon, and rocky planetary bodies in general. SEIS detected marsquakes in Cerberus Fossae in 2019. On 24 December 2021, the seismometer for the InSight mission on Mars detected a large seismic event with a distinct signature. The event was caused by a meteor impact on the surface of Mars, which was confirmed by satellite observations of a newly formed 150-meter crater. As of 21 December 2022, which marks the official end of the InSight mission, SEIS has detected a total of 1319 marsquakes. == Overview == Mars flybys and landings to gather scientific data have been conducted since the 1960s, but quality seismological studies – which would provide detailed information about the interior of Mars – have yet to be


id: shuttle-radar-topography-mission-20260505-0
file: data/en.wikipedia.org/wiki/Shuttle_Radar_Topography_Mission-0.md
category: reference
title: Shuttle Radar Topography Mission
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Shuttle_Radar_Topography_Mission
date_saved: 2026-05-05T09:46:02.602314+00:00
instance: kb-cron
parent: shuttle-radar-topography-mission-20260505-0
summary:
The Shuttle Radar Topography Mission (SRTM) is an international research effort that obtained digital elevation models on a near-global scale from 56°S to 60°N, to generate the most complete high-resolution digital topographic database of Earth prior to the release of the ASTER GDEM in 2009. The technique employed for generating topographic data by radar is known as interferometric synthetic aperture radar. It flew onboard the 11-day STS-99 mission in February 2000. Intermap Technologies was the prime contractor for processing the interferometric synthetic aperture radar data. The elevation models derived from the SRTM data are used in geographic information systems. They can be downloaded freely over the Internet, and their file format (.hgt) is widely supported. The Shuttle Radar Topography Mission is an international project spearheaded by the U.S. National Geospatial-Intelligence Agency (NGA), an agency of the U.S. Department of Defense, and the U.S. National Aeronautics and Space Administration (NASA). == Mission and instrument == The mission consists of an interferometric synthetic aperture radar system based on the older Spaceborne Imaging Radar-C/X-band Synthetic Aperture Radar (SIR-C/X-SAR), previously used on the Shuttle in 1994. It features two antennas, a critical change from SIR-C/X-SAR, allowing single-pass interferometry. One antenna was located in the


id: shuttle-radar-topography-mission-20260505-1
file: data/en.wikipedia.org/wiki/Shuttle_Radar_Topography_Mission-1.md
category: reference
title: Shuttle Radar Topography Mission
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Shuttle_Radar_Topography_Mission
date_saved: 2026-05-05T09:46:02.602314+00:00
instance: kb-cron
parent: shuttle-radar-topography-mission-20260505-0
summary:
==== Highest resolution global release ==== SRTM-GL1 is a void-filled digital elevation model with 1-arcsecond (30 meter) resolution, or alternatively a high-resolution version of "SRTM version 3". It was released in 2014. It is available from the United States Geological Survey web site and the NASA data catalog. The United States Government announced on September 23, 2014 over a United Nations Climate Summit that the highest possible resolution of global topographic data derived from the SRTM mission will be released to public. Before the end of the same year, a 1-arc second global digital elevation model (30 meters) was released. Most parts of the world have been covered by this dataset ranging from 54°S to 60°N latitude except for the Middle East and North Africa area. Missing coverage of the Middle East was completed in August 2015. Jonathan de Ferranti published a short review of the new SRTM-GL1 data product in 2015. The effective resolution is about 50 metres, compared with 100 meters for versions 1 and 2 of ASTER GDEM. Voids remain around Mount Everest and the Swiss/Italian Matterhorn. There are some artificial details (bumps and pits), but at a lower amplitude than ASTER GDEM. === Third-party derivatives ===


id: signs-of-life-detector-20260505-0
file: data/en.wikipedia.org/wiki/Signs_Of_LIfe_Detector-0.md
category: reference
title: Signs Of LIfe Detector
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Signs_Of_LIfe_Detector
date_saved: 2026-05-05T09:46:03.796986+00:00
instance: kb-cron
parent: signs-of-life-detector-20260505-0
summary:
Signs Of LIfe Detector (SOLID) is an analytical instrument under development to detect extraterrestrial life in the form of organic biosignatures obtained from a core drill during planetary exploration. The instrument is based on fluorescent immunoassays and it is being developed by the Spanish Astrobiology Center (CAB) in collaboration with the NASA Astrobiology Institute. SOLID is currently undergoing testing for use in astrobiology space missions that search for common biomolecules that may indicate the presence of extraterrestrial life, past or present. The system was validated in field tests and engineers are looking into ways to refine the method and miniaturize the instrument further. == Science background == Modern astrobiology inquiry has emphasized the search for water on Mars, chemical biosignatures in the permafrost, soil and rocks at the planet's surface, and even biomarker gases in the atmosphere that may give away the presence of past or present life. The detection of preserved organic molecules of unambiguous biological origin is fundamental for the confirmation of present or past life, but the 1976 Viking lander biological experiments failed to detect organics on Mars, and it is suspected it was because of the combined effects of heat applied during analysis and the unexpected


id: sir-2-20260505-0
file: data/en.wikipedia.org/wiki/SIR-2-0.md
category: reference
title: SIR-2
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/SIR-2
date_saved: 2026-05-05T09:46:05.007315+00:00
instance: kb-cron
parent: sir-2-20260505-0
summary:
The SIR-2 instrument is a redesigned, highly compact, monolithic grating, near infrared spectrometer chosen to be a payload on the Indian Chandrayaan-1 satellite. It is an ESA project, and is built by Max Planck Institute for Solar System Research, Polish Academy of Sciences and University of Bergen. == Mission == The mission of the instrument is to map the lunar surface in the near infrared spectrum from 0.9 - 2.4 μm with an unprecedented resolution of 6 nm. The purpose of this is to obtain information on the mineral composition of the moon, which in turn will help getting insight into a number of questions: What is the cause of the global asymmetry of the moon, which on the far side has a thicker crust and lacks the Mare structures which are characteristic for the near side? What was the early thermal evolution of the moon? What is the vertical and lateral structure of the lunar crust and how did it develop? What is the composition and structure of the lunar mantle? Why is the moon different from other planets and how do planets work in terms of surface processes, heat transfer, and geologic evolution? Are the Apollo geophysical measurements


id: solar-x-ray-imager-20260505-0
file: data/en.wikipedia.org/wiki/Solar_X-ray_Imager-0.md
category: reference
title: Solar X-ray Imager
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Solar_X-ray_Imager
date_saved: 2026-05-05T09:46:06.212667+00:00
instance: kb-cron
parent: solar-x-ray-imager-20260505-0
summary:
Solar X-ray Imager (SXI) are full-disc X-ray instruments observing the Sun aboard GOES satellites. The SXI on GOES 12 was the first of its kind and allows the U.S. NOAA to better monitor and predict space weather. == Operation == The Solar X-ray Imager aboard the GOES 12, GOES 13, GOES 14, and GOES 15 NOAA weather satellites is used for early detection of solar flares, coronal mass ejections (CMEs), and space phenomena that impact human spaceflight and military and commercial satellite communications. The Solar X-ray Imager was the first X-ray telescope to take a "full-disk" image of the Sun, providing forecasters with the ability to detect solar storms and real-time solar forecasting by the Space Weather Prediction Center (SWPC). == Imagery == The SXI aboard GOES 12 is a Wolter Type I (Wolter telescope) grazing incidence X-ray telescope designed to record coronal images in continuous sequence at 1-minute intervals. The Solar X-ray Imager obtains images at multiple wavelengths on the electromagnetic spectrum from 6 to 60 angstrom units (Å). The imagery obtained by the XSI and XRS on GOES 12 allowed forecasters to see space phenomena such as coronal holes, whose geomagnetic and proton storms impact electrical grid systems


id: spaceborne-imaging-radar-20260505-0
file: data/en.wikipedia.org/wiki/Spaceborne_Imaging_Radar-0.md
category: reference
title: Spaceborne Imaging Radar
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Spaceborne_Imaging_Radar
date_saved: 2026-05-05T09:46:07.354704+00:00
instance: kb-cron
parent: spaceborne-imaging-radar-20260505-0
summary:
The Spaceborne Imaging Radar (SIR) – full name 'Spaceborne Imaging Radar-C/X-band Synthetic Aperture Radar (SIR-C/X-SAR)', is a synthetic aperture radar which flew on two separate shuttle missions. Once from the Space Shuttle Endeavour in April 1994 on (STS-59) and again in October 1994 on (STS-68). The radar was run by NASA's Space Radar Laboratory. SIR utilizes 3 radar frequencies: L band (24 cm wavelength), C band (6 cm) and X band (3 cm), allowing for study of geology, hydrology, ecology and oceanography. Comparing radar images to data collected by teams of people on the ground as well as aircraft and ships using simultaneous measurements of vegetation, soil moisture, sea state, snow and weather conditions during each flight. The imaging radar was able to take images anytime regardless of clouds cover. The Radar-C system was built and operated by NASA's Jet Propulsion Laboratory (JPL). The mission was a joint work of NASA with the German and Italian space agencies. Each of the week long mission scanned about 50 million square kilometers of the Earth's surface, (19.3 million square miles). The SIR mission revealed hidden river channels in the Sahara Desert indicating significant climate change in the past. SIR was also used


id: spacecraft-atmosphere-monitor-20260505-0
file: data/en.wikipedia.org/wiki/Spacecraft_Atmosphere_Monitor-0.md
category: reference
title: Spacecraft Atmosphere Monitor
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Spacecraft_Atmosphere_Monitor
date_saved: 2026-05-05T09:46:08.543451+00:00
instance: kb-cron
parent: spacecraft-atmosphere-monitor-20260505-0
summary:
The Spacecraft Atmosphere Monitor (SCRAM) is a highly compact gas chromatograph mass spectrometer (GCMS) instrument built by JPL that is a technology demonstration on the International Space Station for monitoring the cabin atmosphere in human spacecraft. SCRAM measures both the major constituents (e.g. nitrogen, oxygen, and carbon dioxide) and trace parts per billion volatile chemicals (e.g. benzene, ethanol, siloxanes) in the spacecraft cabin atmosphere to ensure the health of the astronauts. SCRAM has a total mass of 9.5 kg and uses 40 W (nominal) during operation. SCRAM is an advanced technology demonstration that can be employed on future crewed flight missions, like in the Artemis program and the Orion spacecraft. It was launched to ISS on a Dragon spacecraft on July 25, 2019, and began continuous operations on July 29, 2019. SCRAM was returned to earth aboard SpaceX-25 on Jan. 24, 2022 after almost two years of continuous operations aboard the ISS, exceeding its design lifetime goal of one year. The instrument was returned to JPL on Feb. 15, 2022. This first SCRAM instrument will be refurbished and be flown, along with a second SCRAM unit (SCRAM-2), to ISS in late 2022. The two instruments operating at the same time


id: special-sensor-microwave-imager-20260505-0
file: data/en.wikipedia.org/wiki/Special_sensor_microwave/imager-0.md
category: reference
title: Special sensor microwave/imager
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Special_sensor_microwave/imager
date_saved: 2026-05-05T09:46:09.711725+00:00
instance: kb-cron
parent: special-sensor-microwave-imager-20260505-0
summary:
The Special Sensor Microwave/Imager (SSM/I) is a seven-channel, four-frequency, linearly polarized passive microwave radiometer system. It is flown on board the United States Air Force Defense Meteorological Satellite Program (DMSP) Block 5D-2 satellites. The instrument measures surface/atmospheric microwave brightness temperatures (TBs) at 19.35, 22.235, 37.0 and 85.5 GHz. The four frequencies are sampled in both horizontal and vertical polarizations, except the 22 GHz which is sampled in the vertical only. The SSM/I has been a very successful instrument, superseding the across-track and Dicke radiometer designs of previous systems. Its combination of constant-angle rotary-scanning and total power radiometer design has become standard for passive microwave imagers, e.g. TRMM Microwave Imager, AMSR. Its predecessor, the Scanning Multichannel Microwave Radiometer (SMMR), provided similar information. Its successor, the Special Sensor Microwave Imager / Sounder (SSMIS), is an enhanced eleven-channel, eight-frequency system. == Products == Along with its predecessor SMMR, the SSM/I contributes to an archive of global passive microwave products from late 1978 to present. Information within the SSM/I TBs measurements allow the retrieval of four important meteorological parameters over the ocean: near-surface wind speed (note scalar not vector), total columnar water vapor, total columnar cloud liquid water (liquid water path) and precipitation. Accurate


id: spectrometer-telescope-for-imaging-x-rays-20260505-0
file: data/en.wikipedia.org/wiki/Spectrometer_Telescope_for_Imaging_X-rays-0.md
category: reference
title: Spectrometer Telescope for Imaging X-rays
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Spectrometer_Telescope_for_Imaging_X-rays
date_saved: 2026-05-05T09:46:10.877832+00:00
instance: kb-cron
parent: spectrometer-telescope-for-imaging-x-rays-20260505-0
summary:
The Spectrometer Telescope for Imaging X-rays (STIX) is one of the 10 instruments that are part of the scientific payload for the ESA Solar Orbiter mission launched in 2020. The STIX instrument is an X-ray imaging spectrometer, whose purpose is to study the extremely hot solar plasma and the high-energy electrons accelerated during a solar flare. It can detect X-rays from 4 to 150 keV and exploits an indirect imaging technique based on the moiré effect, to produce images with few arcsec angular resolution in any given energy range. The instrument has been developed by an international collaboration led by the University of Applied Sciences Northwestern Switzerland. == External links == STIX Data Center The spectrometer/telescope for imaging X-rays on board the ESA Solar Orbiter spacecraft ESA Solar Orbiter


id: ssmis-20260505-0
file: data/en.wikipedia.org/wiki/SSMIS-0.md
category: reference
title: SSMIS
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/SSMIS
date_saved: 2026-05-05T09:46:12.001520+00:00
instance: kb-cron
parent: ssmis-20260505-0
summary:
The Special Sensor Microwave Imager / Sounder (SSMIS) is a 24-channel, 21-frequency, linearly polarized passive microwave radiometer system. The instrument is flown on board the United States Air Force Defense Meteorological Satellite Program (DMSP) F-16, F-17, F-18 and F-19 satellites, which were launched in October 2003, November 2006, October 2009, and April 2014, respectively. It is the successor to the Special Sensor Microwave/Imager (SSM/I). The SSMIS on the F19 satellite stopped producing useful data in February 2016. The Department of Defense announced it would cut off access to SSMIS data useful for calculating depth of sea ice and location of hurricanes, as of July 31, 2025. In late July 2025, the Department of Defense announced it will keep the SSMIS data flowing until the sensor fails or the program formally ends in September 2026. == Instrument characteristics == The SSMIS sensor is a passive conically scanning microwave radiometer that combines and extends the current imaging and sounding capabilities of three previously separate DMSP microwave sensors: the SSM/T-1 temperature sounder, the SSMI/T- 2 moisture sounder, and the SSM/I. The SSMIS instrument measures microwave energy at 24 discrete frequencies from 19 to 183 GHz with a swath width of 1700 km. The


id: surface-dust-analyser-20260505-0
file: data/en.wikipedia.org/wiki/Surface_Dust_Analyser-0.md
category: reference
title: Surface Dust Analyser
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Surface_Dust_Analyser
date_saved: 2026-05-05T09:46:13.209747+00:00
instance: kb-cron
parent: surface-dust-analyser-20260505-0
summary:
The SUrface Dust Analyzer (SUDA) is a time-of-flight mass spectrometer of reflectron-type that employs impact ionization and is optimised for a high mass resolution. The instrument was selected in May 2015 to fly on board the Europa Clipper mission which was sent to Jupiter's moon Europa in October, 2024. This instrument will measure the composition of small, solid particles ejected from Europa, providing the opportunity to directly sample the surface and potential plumes on low-altitude flybys. Europa's internal liquid water ocean has been identified as one of the locations in the Solar System that may offer habitable environments to microbial extraterrestrial life. == Overview == The basic idea of compositional mapping is that moons without an atmosphere are surrounded by clouds of dust particles released from their surfaces by meteoroid bombardment. The ejected particles can be sampled and their composition analyzed from orbit or during a spacecraft flyby. Since these grains are direct samples from the moons' icy surfaces, determination of their composition will help to define and constrain the geological activities on and below the moons' surface, the exchange processes with the deeper interior, and assess its internal ocean habitability potential. The instrument is capable of identifying traces of


id: swap-instrument-20260505-0
file: data/en.wikipedia.org/wiki/SWAP_(instrument)-0.md
category: reference
title: SWAP (instrument)
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/SWAP_(instrument)
date_saved: 2026-05-05T09:46:15.034710+00:00
instance: kb-cron
parent: swap-instrument-20260505-0
summary:
The Sun Watcher using Active Pixel System Detector and Image Processing (SWAP) telescope is a compact extreme-ultraviolet (EUV) imager on board the PROBA-2 mission. SWAP provides images of the solar corona at a temperature of roughly 1 million degrees. the instrument was built upon the heritage of the Extreme ultraviolet Imaging Telescope (EIT) which monitored the solar corona from the Solar and Heliospheric Observatory from 1996 until after the launch of the Solar Dynamics Observatory in 2010. SWAP's coronal mass ejection (CME) watch program has collected images at an improved image cadence (typically 1 image every few minutes) since the PROBA-2 launch in 2009. These events include EIT waves (global waves propagating across the solar disc from the CME eruption site), EUV dimming regions (transient coronal holes from where the CME has lifted off), filament instabilities (a specific type of flickering during the rise of a filament). SWAP's EUV images of the corona routinely extend beyond 2 solar radii from the surface of the Sun, much further than was thought possible before the mission was launched. This led to the discovery, in 2021 by Seaton et al. using the SUVI instrument on board NOAA's GOES satellite, that the extended solar


id: swap-new-horizons-20260505-0
file: data/en.wikipedia.org/wiki/SWAP_(New_Horizons)-0.md
category: reference
title: SWAP (New Horizons)
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/SWAP_(New_Horizons)
date_saved: 2026-05-05T09:46:16.200916+00:00
instance: kb-cron
parent: swap-new-horizons-20260505-0
summary:
SWAP (solar wind around Pluto) is a science instrument aboard the unmanned New Horizons space probe, which was designed to fly by dwarf planet Pluto. SWAP was designed to record solar wind en route, at, and beyond Pluto. At Pluto, SWAP's purpose was to record the relationship between the solarwind and ions and/or material entering space from the atmosphere of Pluto. == Background == The atmosphere of Pluto was discovered in 1988, but it remained enigmatic and it was hard to understand an atmosphere existing in such low temperatures (45 K, −230 °C, −380 °F). One of the ideas about Pluto is atmospheric loss, with Pluto being compared to losses from comets. The idea of atmospheric loss was suggested in 1980, even before the atmosphere was discovered. One idea is the photoionization of escaping neutral particles might alter the flow solar wind around the dwarf planet. The atmosphere was known to be very tenuous compared to Earth, and one of the questions was how the gases were interacting with the solar wind and sunlight, likewise weaker at Pluto's orbit than at Earth's. One of the ideas was that Pluto's atmosphere would be stripped away by the solar wind over time.


id: sweap-20260505-0
file: data/en.wikipedia.org/wiki/SWEAP-0.md
category: reference
title: SWEAP
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/SWEAP
date_saved: 2026-05-05T09:46:17.401031+00:00
instance: kb-cron
parent: sweap-20260505-0
summary:
The Solar Wind Electrons Alphas and Protons (SWEAP) is an instrument on the Parker Solar Probe, designed for an unmanned mission to the Sun's outer corona. The Parker Solar Probe was launched by a Delta IV Heavy on 12 August 2018 from Cape Canaveral, Florida. SWEAP includes two types of instruments: the Solar Probe Cup (SPC) and Solar Probe Analyzers (SPAN). SWEAP has four sensors overall, and is designed to take measurements of solar wind including electrons, ions of hydrogen (protons), and helium (the main components of solar wind and the coronal plasma). == Background == Scientists studying emission spectra of the Sun's corona during total solar eclipses thought they had found the presence of a new element they called "coronium." In the late 1930s, Walter Grotrian and Bengt Edlén postulated instead that these spectra were from highly ionized known elements, particularly iron. Since the levels of ionization they proposed required temperatures in the millions of Kelvins, this idea was initially not accepted as those temperatures were far higher than the actual surface of the Sun. This disparity was thought impossible as the corona should be cooler than the Sun, given that it lacks any apparent heat source of its


id: tagsam-20260505-0
file: data/en.wikipedia.org/wiki/TAGSAM-0.md
category: reference
title: TAGSAM
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/TAGSAM
date_saved: 2026-05-05T09:46:18.613929+00:00
instance: kb-cron
parent: tagsam-20260505-0
summary:
TAGSAM or Touch-and-Go Sample Acquisition Mechanism is a robotic arm on the OSIRIS-REx space probe designed and used for collecting a sample from asteroid 101955 Bennu. OSIRIS-REx was launched in 2016. It arrived at asteroid Bennu in December 2018, and began scientific studies. It collected a sample of the material making up the surface of Bennu in 2020 and returned it to Earth in 2023. == Overview == TAGSAM is a robotic arm attached to the main body of the spacecraft that collects a sample from the asteroid, and puts the samples into the Earth return vehicle. Bennu is about 500 meters in diameter and has very low gravity, so the arm must perform the collection in near zero gravity, yet still contend with some gravitational forces from the asteroid. One issue with small asteroids is their unique gravitational environment, and Bennu became the smallest body orbited by a spacecraft. TAGSAM was designed to take up to three samples from the asteroid, although in the event the first sample was so large no other samples were attempted. The collection head was filled using a nitrogen gas injection that stired up the regolith. The arm is about 11 feet (3.4 meters)


id: temperature-and-winds-for-insight-20260505-0
file: data/en.wikipedia.org/wiki/Temperature_and_Winds_for_InSight-0.md
category: reference
title: Temperature and Winds for InSight
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Temperature_and_Winds_for_InSight
date_saved: 2026-05-05T09:46:19.743594+00:00
instance: kb-cron
parent: temperature-and-winds-for-insight-20260505-0
summary:
Temperature and Winds for InSight (TWINS) is a NASA meteorological suite of instruments on board the InSight lander that landed on Mars on 26 November 2018. TWINS provides continuous wind and air temperature measurements to help understand the seismic data from the Seismic Experiment for Interior Structure (SEIS) instrument. The instruments were developed by the Spanish Astrobiology Center at Madrid, Spain. == Overview == TWINS is based on the heritage from REMS (Rover Environmental Monitoring Station) on board the Curiosity rover, with enhanced performances in terms of dynamic range and resolution. TWINS provides continuous wind and air temperature measurements to help understand the seismic data from the SEIS instrument. While probing the internal structure of Mars is the primary scientific goal of the InSight mission, atmospheric science remains a key science objective. InSight will provide a continuous and higher-frequency record of pressure, air temperature and winds at the surface of Mars than previous in situ missions. The sensors include thermometers, and an anemometer to measure wind speed and direction twice per second. Additional sensors are the InSight FluxGate (IFG) magnetometer provided by University of California, Los Angeles (UCLA) to measure the direction and magnitude of magnetic fields such as those


id: thermal-emission-spectrometer-20260505-0
file: data/en.wikipedia.org/wiki/Thermal_Emission_Spectrometer-0.md
category: reference
title: Thermal Emission Spectrometer
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Thermal_Emission_Spectrometer
date_saved: 2026-05-05T09:46:20.917037+00:00
instance: kb-cron
parent: thermal-emission-spectrometer-20260505-0
summary:
The Thermal Emission Spectrometer (TES) was an instrument on board Mars Global Surveyor. TES collected two types of data, hyperspectral thermal infrared data from 6 to 50 micrometres (μm) and bolometric visible-near infrared (0.3 to 2.9 μm) measurements. TES had six detectors arranged in a 2x3 array, and each detector had a field of view of approximately 3 × 6 km on the surface of Mars. The TES instrument used the natural harmonic vibrations of the chemical bonds in materials to determine the composition of gases, liquids, and solids. TES identified a large (30,000 square-kilometer) area that contained the mineral olivine. Olivine was found in the Nili Fossae formation. It is thought that the ancient impact that created the Isidis basin resulted in faults that exposed the olivine. Olivine is present in many mafic volcanic rocks. In the presence of water it weathers into minerals such as goethite, chlorite, smectite, maghemite, and hematite. Olivine was also discovered in many other small outcrops within 60 degrees north and south of the equator. Olivine has also been found in the SNC (shergottite, nakhlite, and chassigny) meteorites that are generally accepted to have come from Mars. Later studies found the olivine-rich rocks to


id: total-ozone-mapping-spectrometer-20260505-0
file: data/en.wikipedia.org/wiki/Total_Ozone_Mapping_Spectrometer-0.md
category: reference
title: Total Ozone Mapping Spectrometer
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Total_Ozone_Mapping_Spectrometer
date_saved: 2026-05-05T09:46:22.162336+00:00
instance: kb-cron
parent: total-ozone-mapping-spectrometer-20260505-0
summary:
The Total Ozone Mapping Spectrometer (TOMS) was a NASA satellite instrument, specifically a spectrometer, for measuring the ozone layer. Of the five TOMS instruments which were built, four entered successful orbit. The satellites carrying TOMS instruments were: Nimbus 7; launched October 24, 1978. Operated until 1 August 1994. Carried TOMS instrument number 1. Meteor-3-5; launched 15 August 1991. Operated until December 1994. Was the first and last Soviet satellite to carry a USA made instrument. Carried TOMS instrument number 2. ADEOS I; launched 17 August 1996. Operated until 30 June 1997. Mission was cut short by a spacecraft failure. TOMS-Earth Probe; launched on July 2, 1996. Operated until 2 December 2006. Carried TOMS instrument number 3. QuikTOMS; launched 21 September 2001. Suffered launch failure and did not enter orbit. Nimbus 7 and Meteor-3-5 provided global measurements of total column ozone on a daily basis and together provided a complete data set of daily ozone from November 1978 to December 1994. After an eighteen-month period when the program had no on-orbit capability, TOMS-Earth Probe launched on 2 July 1996, followed by ADEOS I. ADEOS I was launched on August 17, 1996, and the TOMS-instrument onboard provided data until the satellite which


id: tropospheric-emission-spectrometer-20260505-0
file: data/en.wikipedia.org/wiki/Tropospheric_Emission_Spectrometer-0.md
category: reference
title: Tropospheric Emission Spectrometer
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Tropospheric_Emission_Spectrometer
date_saved: 2026-05-05T09:46:23.334091+00:00
instance: kb-cron
parent: tropospheric-emission-spectrometer-20260505-0
summary:
Tropospheric Emission Spectrometer or TES was a satellite instrument designed to measure the state of the earth's troposphere. == Overview == TES was a high-resolution infrared Fourier Transform spectrometer and provided key data for studying tropospheric chemistry, troposphere-biosphere interaction, and troposphere-stratosphere exchanges. It was built for NASA by the Jet Propulsion Laboratory, California Institute of Technology in Pasadena, California. It was successfully launched into polar orbit by a Delta II 7920-10L rocket aboard NASA's third Earth Observing Systems spacecraft (EOS-Aura) at 10:02 UTC on July 15, 2004. Originally planned as a 5-year mission, it was decommissioned after almost 14 years on January 31, 2018. == References == == External links == NASA JPL's TES page NASA Aura TES page


id: tropospheric-emissions-monitoring-of-pollution-20260505-0
file: data/en.wikipedia.org/wiki/Tropospheric_Emissions:_Monitoring_of_Pollution-0.md
category: reference
title: Tropospheric Emissions: Monitoring of Pollution
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Tropospheric_Emissions:_Monitoring_of_Pollution
date_saved: 2026-05-05T09:46:24.579325+00:00
instance: kb-cron
parent: tropospheric-emissions-monitoring-of-pollution-20260505-0
summary:
Tropospheric Emissions: Monitoring of Pollution (TEMPO) is a space-based spectrometer designed to measure air pollution across greater North America at a high resolution and on an hourly basis. The ultraviolet–visible spectrometer will provide hourly data on ozone, nitrogen dioxide, and formaldehyde in the atmosphere. TEMPO is a hosted payload on a commercial geostationary communication satellite with a constant view of North America. TEMPO's spectrometer measures reflected sunlight from the Earth's atmosphere and separates it into 2,000 component wavelengths. It will scan North America from the Pacific Ocean to the Atlantic Ocean and from the Alberta oil sands to Mexico City. TEMPO will form part of a geostationary constellation of pollution-monitoring assets, along with the planned Sentinel-4 from ESA and Geostationary Environment Monitoring Spectrometer (GEMS) from South Korea's KARI. On 3 February 2020, Intelsat announced that the Intelsat 40e satellite will host TEMPO. Maxar Technologies, the builder of the satellite, is responsible for payload integration. The launch occurred on 7 April 2023. == Earth Venture-Instrument program == TEMPO, which is a collaboration between NASA and the Smithsonian Astrophysical Observatory, is NASA's first Earth Venture-Instrument (EVI) mission. The EVI program is an element within the Earth System Science Pathfinder (ESSP) program office,


id: urey-instrument-20260505-0
file: data/en.wikipedia.org/wiki/Urey_instrument-0.md
category: reference
title: Urey instrument
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Urey_instrument
date_saved: 2026-05-05T09:46:25.784106+00:00
instance: kb-cron
parent: urey-instrument-20260505-0
summary:
The Urey instrument, or Urey: Mars Organic and Oxidant Detector was a developmental spacecraft instrument for detecting organic compounds including amino acids. == Overview == It was funded by NASA and tested in the Atacama Desert in the early 2000s. Urey was selected by NASA for further development in support ExoMars or any future Mars mission that could use Urey along with Mars Organic Molecule Analyzer, or Moma in 2007, funded with 1.5 million USD total (750k each). Urey was a suite of instruments that built on 15 years of research into detecting organic molecules. Urey is a design for in situ biomarker detection, and it was tested in the early 2000s. The device would also study the mysterious oxidants in Mars regolith. Urey was previously included on ExoMars rover, now the Rosalind Franklin rover, in one of its iterations, and would have searched for organic compounds in Martian rocks and soils as evidence for past life and/or prebiotic chemistry. Starting with a hot water extraction, only soluble compounds are left for further analysis. Sublimation, and capillary electrophoresis makes it possible to identify amino acids. The detection would be by laser-induced fluorescence, a highly sensitive technique, capable of parts-per-trillion sensitivity.


id: uvs-juno-20260505-0
file: data/en.wikipedia.org/wiki/UVS_(Juno)-0.md
category: reference
title: UVS (Juno)
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/UVS_(Juno)
date_saved: 2026-05-05T09:46:41.188598+00:00
instance: kb-cron
parent: uvs-juno-20260505-0
summary:
UVS, known as the Ultraviolet Spectrograph or Ultraviolet Imaging Spectrometer is the name of an instrument on the Juno orbiter for Jupiter. The instrument is an imaging spectrometer that observes the ultraviolet range of light wavelengths, which is shorter wavelengths than visible light but longer than X-rays. Specifically, it is focused on making remote observations of the aurora, detecting the emissions of gases such as hydrogen in the far-ultraviolet. UVS will observes light from as short a wavelength as 70 nm up to 200 nm, which is in the extreme and far ultraviolet range of light. The source of aurora emissions of Jupiter is one of the goals of the instrument. UVS is one of many instruments on Juno, but it is in particular designed to operate in conjunction with JADE, which observes high-energy particles. With both instruments operating together, both the UV emissions and high-energy particles at the same place and time can be synthesized. This supports the Goal of determining the source of the Jovian magnetic field. There has been a problem understanding the Jovian aurora, ever since Chandra determined X-rays were coming not from, as it was thought Io's orbit but from the polar regions. Every 45


id: venetia-burney-student-dust-counter-20260505-0
file: data/en.wikipedia.org/wiki/Venetia_Burney_Student_Dust_Counter-0.md
category: reference
title: Venetia Burney Student Dust Counter
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Venetia_Burney_Student_Dust_Counter
date_saved: 2026-05-05T09:46:42.373489+00:00
instance: kb-cron
parent: venetia-burney-student-dust-counter-20260505-0
summary:
The Venetia Burney Student Dust Counter (VBSDC) is a scientific instrument aboard the uncrewed New Horizons space probe that is designed to detect dust impacts in outer space. VBSDC is the first planetary science instrument to be built by students. The dust counter was launched in 2006, and named later that year after Venetia Burney, the young girl who originally named Pluto. The detector works when dust strikes films of polarized polyvinylidene fluoride (PVDF), which generates an electrical charge. The space dust is then detected over the course of the New Horizons spacecraft flight out of the Solar System and past Pluto. == Overview == In 2010, VBSDC collected data on dust past 18 AU (1.67 billion miles), which is the distance the Pioneer 10 and Pioneer 11 dust counters stopped working. Five other spacecraft have carried dust detectors beyond the asteroid belt including Pioneer 10, Pioneer 11, Ulysses (heliocentric orbit out to the distance of Jupiter), Galileo (Jupiter Orbiter), and Cassini (Saturn orbiter). The Voyager 1 and Voyager 2 spacecraft did detect dust by using data from the Plasma Wave instrument, but did not have dedicated dust detection instruments. The Pioneer dust detectors stopped working at 18 AU. The


id: venus-emissivity-mapper-20260505-0
file: data/en.wikipedia.org/wiki/Venus_Emissivity_Mapper-0.md
category: reference
title: Venus Emissivity Mapper
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Venus_Emissivity_Mapper
date_saved: 2026-05-05T09:46:43.653791+00:00
instance: kb-cron
parent: venus-emissivity-mapper-20260505-0
summary:
The Venus Emissivity Mapper (VEM) is a spectrometer for mapping the surface composition of Venus through a distinct number of atmospheric spectral windows. It will be one of the two payloads on board the VERITAS mission, and will also be the VenSpec-M channel of the EnVision mission's spectrometer suite. == Overview == While Earth and Venus are similar in many aspects, they evolved very differently and currently have distinct surface and atmospheric environments. Where Earth's surface has liquid water and supports life, Venus experiences a mean surface temperature of over 400 °C, and a carbon dioxide rich atmosphere with a surface pressure of about 92 times that of Earth at sea-level. Little is known about Venus' surface composition. The dense atmosphere and its cloud layers are mostly opaque to visible and infrared radiation, making remote sensing a challenge. As light travels through the atmosphere, it is attenuated by absorption and scattering, and it is blurred by the emissions of the atmosphere itself. Observations of Venus have shown that the surface can be observed through a number of narrow infrared bands. Using this technique Venus Express was able to observe fresh basalt, pointing towards recent volcanic activity on the surface. The


id: venus-emissivity-mapper-20260505-1
file: data/en.wikipedia.org/wiki/Venus_Emissivity_Mapper-1.md
category: reference
title: Venus Emissivity Mapper
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Venus_Emissivity_Mapper
date_saved: 2026-05-05T09:46:43.653791+00:00
instance: kb-cron
parent: venus-emissivity-mapper-20260505-0
summary:
The optics sub-system is a three lens system, provided by LESIA, Observatoire de Paris, France. First, a telescope with an aperture of 8 mm and a focal length of 40.5 mm projects the scene on the filter array. From there, it is then imaged on the focal plane through two more lenses with a combined magnification factor of 0.4. The optics have a total transmittance of 0.88, not taking into account the filters. The focal plane array (VEMFPA) consists of a Xenics XSW-640 InGaAs detector, which has a resolution of 640x512 pixel, a FOV of 30°×45°, a pixel pitch of 20 μm, and a pixel FOV of 0.07°×0.07°. The imaging electronics unit used is LM98640QML-SP from Texas Instruments. InGaAs detectors have been used in deep space successfully over many years, making it a safe choice. This specific unit is currently in use on the ExoMars Trace Gas Orbiter. The filter array is provided by CNES Toulouse Archived 2022-03-14 at the Wayback Machine, France. Narrow-band filters takes care of only transmitting the spectral region of interest. Based on the 4% relative emissivity that is needed to differentiate between the different rock types, the signal-to-noise ratio (SNR) for each band is derived


id: viking-lander-biological-experiments-20260505-0
file: data/en.wikipedia.org/wiki/Viking_lander_biological_experiments-0.md
category: reference
title: Viking lander biological experiments
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Viking_lander_biological_experiments
date_saved: 2026-05-05T09:46:44.854256+00:00
instance: kb-cron
parent: viking-lander-biological-experiments-20260505-0
summary:
In 1976 two identical Viking program landers each carried four types of biological experiments to the surface of Mars. The first successful Mars landers, Viking 1 and Viking 2, then carried out experiments to look for biosignatures of microbial life on Mars. The landers each used a robotic arm to pick up and place soil samples into sealed test containers on the craft. The two landers carried out the same tests at two places on Mars' surface, Viking 1 near the equator and Viking 2 further north. == The experiments == The four experiments below are presented in the order in which they were carried out by the two Viking landers. The biology team leader for the Viking program was Harold P. Klein (NASA Ames). === Gas chromatograph – mass spectrometer === A gas chromatograph – mass spectrometer (GCMS) is a device that separates vapor components chemically via a gas chromatograph and then feeds the result into a mass spectrometer, which measures the molecular weight of each chemical. As a result, it can separate, identify, and quantify a large number of different chemicals. The GCMS (PI: Klaus Biemann, MIT) was used to analyze the components of untreated Martian soil, and


id: viking-lander-biological-experiments-20260505-1
file: data/en.wikipedia.org/wiki/Viking_lander_biological_experiments-1.md
category: reference
title: Viking lander biological experiments
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Viking_lander_biological_experiments
date_saved: 2026-05-05T09:46:44.854256+00:00
instance: kb-cron
parent: viking-lander-biological-experiments-20260505-0
summary:
=== Labeled release === The labeled release (LR) experiment (PI: Gilbert Levin, Biospherics Inc.) gave the most promise for exobiologists. In the LR experiment, a sample of Martian soil was inoculated with a drop of very dilute aqueous nutrient solution. The nutrients (7 molecular compounds that were Miller-Urey products) were tagged with radioactive 14C. The air above the soil was monitored for the evolution of radioactive 14CO2 (or other carbon-based) gas as evidence that microorganisms in the soil had metabolized one or more of the nutrients. Such a result was to be followed with the control part of the experiment as described for the PR below. The result was quite a surprise, considering the negative results of the first two tests, with a steady stream of radioactive gases being given off by the soil immediately following the first injection. The experiment was done by both Viking probes, the first using a sample from the surface exposed to sunlight and the second probe taking the sample from underneath a rock; both initial injections came back positive. Sterilization control tests were subsequently carried out by heating various soil samples. Samples heated for 3 hours at 160 °C gave off no radioactive gas


id: viking-lander-biological-experiments-20260505-2
file: data/en.wikipedia.org/wiki/Viking_lander_biological_experiments-2.md
category: reference
title: Viking lander biological experiments
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Viking_lander_biological_experiments
date_saved: 2026-05-05T09:46:44.854256+00:00
instance: kb-cron
parent: viking-lander-biological-experiments-20260505-0
summary:
Organic compounds seem to be common, for example, on asteroids, meteorites, comets and the icy bodies orbiting the Sun, so detecting no trace of any organic compound on the surface of Mars came as a surprise. The GC-MS was definitely working, because the controls were effective and it was able to detect traces of chlorine, attributed to the cleaning solvents that had been used to sterilize it prior to launch. A reanalysis of the GC-MS data was performed in 2018, suggesting that organic compounds may actually have been detected, corroborating with data from the Curiosity rover. At the time, the total absence of organic material on the surface made the results of the biology experiments moot, since metabolism involving organic compounds were what those experiments were designed to detect. The general scientific community surmises that the Viking's biological tests remain inconclusive, and can be explained by purely chemical processes. Despite the positive result from the Labeled Release experiment, a general assessment is that the results seen in the four experiments are best explained by oxidative chemical reactions with the Martian soil. One of the current conclusions is that the Martian soil, being continuously exposed to UV light from the Sun


id: viking-lander-biological-experiments-20260505-3
file: data/en.wikipedia.org/wiki/Viking_lander_biological_experiments-3.md
category: reference
title: Viking lander biological experiments
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Viking_lander_biological_experiments
date_saved: 2026-05-05T09:46:44.854256+00:00
instance: kb-cron
parent: viking-lander-biological-experiments-20260505-0
summary:
== Controversy == Before the discovery of the oxidizer perchlorate on Mars in 2008, some theories remained opposed to the general scientific conclusion. An investigator suggested that the biological explanation of the lack of detected organics by GC-MS could be that the oxidizing inventory of the H2O2-H2O solvent well exceeded the reducing power of the organic compounds of the organisms. It has also been argued that the Labeled Release (LR) experiment detected so few metabolising organisms in the Martian soil, that it would have been impossible for the gas chromatograph to detect them. This view has been put forward by the designer of the LR experiment, Gilbert Levin, who believes the positive LR results are diagnostic for life on Mars. He and others have conducted ongoing experiments attempting to reproduce the Viking data, either with biological or non-biological materials on Earth. While no experiment has ever precisely duplicated the Mars LR test and control results, experiments with hydrogen peroxide-saturated titanium dioxide have produced similar results. While the majority of astrobiologists still conclude that the Viking biological experiments were inconclusive or negative, Gilbert Levin is not alone in believing otherwise. The current claim for life on Mars is grounded on old


id: waves-juno-20260505-0
file: data/en.wikipedia.org/wiki/Waves_(Juno)-0.md
category: reference
title: Waves (Juno)
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Waves_(Juno)
date_saved: 2026-05-05T09:46:46.071009+00:00
instance: kb-cron
parent: waves-juno-20260505-0
summary:
Waves is an experiment on the Juno spacecraft for studying radio and plasma waves. It is part of a collection of various types of instruments and experiments on the spacecraft; Waves is oriented towards understanding fields and particles in the Jupiter's magnetosphere. Waves is on board the uncrewed Juno spacecraft, which was launched in 2011 and arrived at Jupiter in the summer of 2016. The major focus of study for Waves is Jupiter's magnetosphere, which if could be seen from Earth would be about twice the size of a full moon. The magnetosphere has a tear drop shape, and that tail extends away from the Sun by at least 5 AU (Earth-Sun distances). The Waves instrument is designed to help understand the interaction between Jupiter's atmosphere, its magnetic field, its magnetosphere, and to understand Jupiter's auroras. It is designed to detect radio frequencies from 50 Hz up to 40,000,000 Hz (40 MHz), and magnetic fields from 50 Hz to 20,000 Hz (20 kHz). It has two main sensors: a dipole antenna and a magnetic search coil. The dipole antenna has two whip antennas that extend 2.8 meters (110 inches/ 9.1 feet) and are attached to the main body of the


id: wisdom-radar-20260505-0
file: data/en.wikipedia.org/wiki/WISDOM_(radar)-0.md
category: reference
title: WISDOM (radar)
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/WISDOM_(radar)
date_saved: 2026-05-05T09:46:47.299152+00:00
instance: kb-cron
parent: wisdom-radar-20260505-0
summary:
WISDOM (Water Ice and Subsurface Deposit Observation on Mars) is a ground-penetrating radar that is part of the science payload on board the European Space Agency's Rosalind Franklin rover, tasked to search for biosignatures and biomarkers on Mars. The rover is planned to be launched not earlier than 2028 and land on Mars in 2029. == Overview == The search for evidence of past or present life on Mars is the principal objective of the ExoMars programme. If such evidence exists, it will most likely be in the subsurface, where organic molecules are shielded from the destructive effects of ionizing radiation and atmospheric oxidants. For this reason, the Rosalind Franklin rover mission has been optimized to investigate the subsurface and sample those locations where conditions for the preservation of evidence of past life are most likely to be found. WISDOM is a step frequency radar that operates in the frequency range from 0.5 to 3 GHz. It will provide high-resolution 3D imaging down to a depth of 3 metres. WISDOM will use UHF radar pulses to provide the three-dimensional geological context of the shallow subsurface underneath the ExoMars rover. It will be used to identify optimal drilling sites and to


id: exolife-finder-20260505-0
file: data/en.wikipedia.org/wiki/ExoLife_Finder-0.md
category: reference
title: ExoLife Finder
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/ExoLife_Finder
date_saved: 2026-05-05T09:46:48.916937+00:00
instance: kb-cron
parent: exolife-finder-20260505-0
summary:
The ExoLife Finder (ELF) telescope is an under-development, hybrid interferometric telescope being designed at the Instituto de Astrofisica de Canarias (IAC) for the direct detection and imaging of exoplanets and potentially water-bearing exoplanets. Developed by a collaboration of scientists and engineers including the PLANETS Foundation, the ELF aims to analyze the surfaces and atmospheres of exoplanets for evidence of life, focusing on nearby star systems within 25 light years of Earth. The telescope's design features non-redundant circular arrays of 5-meter-scale mirrors and tensegrity-based mechanical support with an outer diameter of 35m. It uses multiple layers of advanced atmospheric wavefront sensing and control. It is a scalable optical concept, and could be built within a 10 year timeframe. A 3.5-meter precursor called the Small ELF (SELF) is currently being built in the Canary Islands. The ELF's first targets will include nearby stars cooler than the Sun. ELF incorporates several new technologies in order to study exoplanets that could be 100 million times fainter than the stars they orbit. This combination of technologies results in smoother and lighter optics compared to conventional telescope mirrors and greater control of optical diffraction and wavefront errors created by the atmosphere. According to the team behind


id: telescope-20260505-0
file: data/en.wikipedia.org/wiki/Telescope-0.md
category: reference
title: Telescope
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Telescope
date_saved: 2026-05-05T09:46:50.137020+00:00
instance: kb-cron
parent: telescope-20260505-0
summary:
A telescope is a device used to observe distant objects by their emission, absorption, or reflection of electromagnetic radiation. Originally, it was an optical instrument using lenses, curved mirrors, or a combination of both to observe distant objects – an optical telescope. Nowadays, the word "telescope" is defined as a wide range of instruments capable of detecting different regions of the electromagnetic spectrum, and in some cases other types of detectors. The first known practical telescopes were refracting telescopes with glass lenses and were invented in the Netherlands at the beginning of the 17th century. They were used for both terrestrial applications and astronomy. The reflecting telescope, which uses mirrors to collect and focus light, was invented within a few decades of the first refracting telescope. In the 20th century, many new types of telescopes were invented, including radio telescopes in the 1930s and infrared telescopes in the 1960s. == Etymology == The word telescope was coined in 1611 by the Greek mathematician Giovanni Demisiani for one of Galileo Galilei's instruments presented at a banquet at the Accademia dei Lincei. In the Starry Messenger, Galileo had used the Latin term perspicillum. The root of the word is from the Ancient


id: telescope-20260505-1
file: data/en.wikipedia.org/wiki/Telescope-1.md
category: reference
title: Telescope
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Telescope
date_saved: 2026-05-05T09:46:50.137020+00:00
instance: kb-cron
parent: telescope-20260505-0
summary:
=== Radio and submillimeter === Radio telescopes are directional radio antennas that typically employ a large dish to collect radio waves. The dishes are sometimes constructed of a conductive wire mesh whose openings are smaller than the wavelength being observed. Unlike an optical telescope, which produces a magnified image of the patch of sky being observed, a traditional radio telescope dish contains a single receiver and records a single time-varying signal characteristic of the observed region; this signal may be sampled at various frequencies. In some newer radio telescope designs, a single dish contains an array of several receivers; this is known as a focal-plane array. By collecting and correlating signals simultaneously received by several dishes, high-resolution images can be computed. Such multi-dish arrays are known as astronomical interferometers and the technique is called aperture synthesis. The 'virtual' apertures of these arrays are similar in size to the distance between the telescopes. As of 2005, the record array size is many times the diameter of the Earth – using space-based very-long-baseline interferometry (VLBI) telescopes such as the Japanese HALCA (Highly Advanced Laboratory for Communications and Astronomy) VSOP (VLBI Space Observatory Program) satellite. Aperture synthesis is now also being applied to


id: 400-years-of-the-telescope-20260505-0
file: data/en.wikipedia.org/wiki/400_Years_of_the_Telescope-0.md
category: reference
title: 400 Years of the Telescope
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/400_Years_of_the_Telescope
date_saved: 2026-05-05T09:46:51.340241+00:00
instance: kb-cron
parent: 400-years-of-the-telescope-20260505-0
summary:
400 Years of the Telescope: A Journey of Science, Technology and Thought is a 2009 American documentary film that was created to coincide with the International Year of Astronomy in 2009. Directed by Kris Koenig, it chronicles the history of the telescope from the time of Galileo and features interviews with leading astrophysicists and cosmologists from around the world, who explain concepts ranging from Galileo's first use of the telescope to view the moons of Jupiter, to the latest discoveries in space, including new ideas about life on other planets and dark energy, a mysterious vacuum energy that is accelerating the expansion of the universe. == Cast == === Actors === Han Beekman Mavt Steketee Stefano Lecci Herman Boerman Irma Hartog Hallam Murray Nils Koenig Madison Royal Galileo voices Stefano Lecci Francesca Giannini == Production == The film's development team included Donald Goldsmith, a well-known astronomy writer on the Carl Sagan Cosmos team, and Albert Van Helden, a leading authority on the history of the telescope. It was shot on RED Digital Cinema at the world's leading universities and observatories including the European Southern Observatory, Institute for Astronomy, SETI Institute, Space Telescope Science Institute, Anglo-Australian Observatory, and Harvard University. Among


id: active-optics-20260505-0
file: data/en.wikipedia.org/wiki/Active_optics-0.md
category: reference
title: Active optics
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Active_optics
date_saved: 2026-05-05T09:46:52.527679+00:00
instance: kb-cron
parent: active-optics-20260505-0
summary:
Active optics is a technology used with reflecting telescopes developed in the 1980s, which actively shapes a telescope's mirrors to prevent deformation due to external influences such as wind, temperature, and mechanical stress. Without active optics, the construction of 8 metre class telescopes is not possible, nor would telescopes with segmented mirrors be feasible. This method is used by, among others, the Nordic Optical Telescope, the New Technology Telescope, the Telescopio Nazionale Galileo and the Keck telescopes, as well as all of the largest telescopes built since the mid-1990s. Active optics is not to be confused with adaptive optics, which operates at a shorter timescale and corrects atmospheric distortions. == In astronomy == Most modern telescopes are reflectors, with the primary element being a very large mirror. Historically, primary mirrors were quite thick in order to maintain the correct surface figure in spite of forces tending to deform it, like wind and the mirror's own weight. This limited their maximum diameter to 5 or 6 metres (200 or 230 inches), such as Palomar Observatory's Hale Telescope. A new generation of telescopes built since the 1980s uses thin, lighter weight mirrors instead. They are too thin to maintain themselves rigidly in


id: adaptive-optics-20260505-0
file: data/en.wikipedia.org/wiki/Adaptive_optics-0.md
category: reference
title: Adaptive optics
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Adaptive_optics
date_saved: 2026-05-05T09:46:53.774429+00:00
instance: kb-cron
parent: adaptive-optics-20260505-0
summary:
Adaptive optics (AO) is a technique of precisely deforming a mirror in order to compensate for light distortion. It is used in astronomical telescopes and laser communication systems to remove the effects of atmospheric distortion, in microscopy, optical fabrication and in retinal imaging systems (ophthalmoscopy) to reduce optical aberrations. Adaptive optics works by measuring the distortions in a wavefront and compensating for them with a device that corrects those errors such as a deformable mirror or a liquid crystal array. Adaptive optics should not be confused with active optics, which work on a longer timescale to correct the primary mirror geometry. Other methods can achieve resolving power exceeding the limit imposed by atmospheric distortion, such as speckle imaging, aperture synthesis, and lucky imaging, or by moving outside the atmosphere with space telescopes, such as the Hubble Space Telescope. == History == Adaptive optics was first envisioned by Horace W. Babcock in 1953, and was also considered in science fiction, as in Poul Anderson's novel Tau Zero (1970), but it did not come into common usage until advances in computer technology during the 1990s made the technique practical. Some of the initial development work on adaptive optics was done by the


id: adaptive-optics-20260505-1
file: data/en.wikipedia.org/wiki/Adaptive_optics-1.md
category: reference
title: Adaptive optics
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Adaptive_optics
date_saved: 2026-05-05T09:46:53.774429+00:00
instance: kb-cron
parent: adaptive-optics-20260505-0
summary:
An alternative is the use of a laser beam to generate a reference light source (a laser guide star, LGS) in the atmosphere. There are two kinds of LGSs: Rayleigh guide stars and sodium guide stars. Rayleigh guide stars work by propagating a laser, usually at near ultraviolet wavelengths, and detecting the backscatter from air at altitudes between 15 and 25 km (49,000 and 82,000 ft). Sodium guide stars use laser light at 589 nm to resonantly excite sodium atoms higher in the mesosphere and thermosphere, which then appear to "glow". The LGS can then be used as a wavefront reference in the same way as a natural guide star – except that (much fainter) natural reference stars are still required for image position (tip/tilt) information. The lasers are often pulsed, with measurement of the atmosphere being limited to a window occurring a few microseconds after the pulse has been launched. This allows the system to ignore most scattered light at ground level; only light which has travelled for several microseconds high up into the atmosphere and back is actually detected.} == In retinal imaging == Adaptive optics has applications in ophthalmology. Ocular aberrations are distortions in the wavefront passing


id: adaptive-optics-20260505-2
file: data/en.wikipedia.org/wiki/Adaptive_optics-2.md
category: reference
title: Adaptive optics
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Adaptive_optics
date_saved: 2026-05-05T09:46:53.774429+00:00
instance: kb-cron
parent: adaptive-optics-20260505-0
summary:
Besides its use for improving nighttime astronomical imaging and retinal imaging, adaptive optics technology has also been used in other settings. Adaptive optics is used for solar astronomy at observatories such as the Swedish 1-m Solar Telescope, Dunn Solar Telescope, and Big Bear Solar Observatory. It is also expected to play a military role by allowing ground-based and airborne laser weapons to reach and destroy targets at a distance including satellites in orbit. The Missile Defense Agency Airborne Laser program is the principal example of this. Adaptive optics has been used to enhance the performance of classical and quantum free-space optical communication systems, and to control the spatial output of optical fibers. Medical applications include imaging of the retina, where it has been combined with optical coherence tomography. Also the development of Adaptive Optics Scanning Laser Ophthalmoscope (AOSLO) has enabled correcting for the aberrations of the wavefront that is reflected from the human retina and to take diffraction limited images of the human rods and cones. Adaptive and active optics are also being developed for use in glasses to achieve better than 20/20 vision, initially for military applications. After propagation of a wavefront, parts of it may overlap leading to


id: altazimuth-mount-20260505-0
file: data/en.wikipedia.org/wiki/Altazimuth_mount-0.md
category: reference
title: Altazimuth mount
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Altazimuth_mount
date_saved: 2026-05-05T09:46:54.951664+00:00
instance: kb-cron
parent: altazimuth-mount-20260505-0
summary:
An altazimuth mount or alt-azimuth mount is a simple two-axis mount for supporting and rotating an instrument about two perpendicular axes – one vertical and the other horizontal. Rotation about the vertical axis varies the azimuth (compass bearing) of the pointing direction of the instrument. Rotation about the horizontal axis varies the altitude angle (angle of elevation) of the pointing direction. These mounts are used, for example, with telescopes, cameras, radio antennas, heliostat mirrors, solar panels, and guns and similar weapons. Several names are given to this kind of mount, including altitude-azimuth, azimuth-elevation and various abbreviations thereof. A gun turret is essentially an alt-azimuth mount for a gun, and a standard camera tripod is an alt-azimuth mount as well. == Astronomical telescope altazimuth mounts == When used as an astronomical telescope mount, the biggest advantage of an alt-azimuth mount is the simplicity of its mechanical design. The primary disadvantage is its inability to follow astronomical objects in the night sky as the Earth spins on its axis. On the other hand, an equatorial mount only needs to be rotated about a single axis, at a constant rate, to follow the rotation of the night sky (diurnal motion). Altazimuth mounts need


id: antique-telescope-society-20260505-0
file: data/en.wikipedia.org/wiki/Antique_Telescope_Society-0.md
category: reference
title: Antique Telescope Society
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Antique_Telescope_Society
date_saved: 2026-05-05T09:46:56.137084+00:00
instance: kb-cron
parent: antique-telescope-society-20260505-0
summary:
The Antique Telescope Society (ATS) is a society for people interested in antique telescopes, binoculars, instruments, books, atlases, etc. It was established in 1992 and presently based in Virginia, the USA. The society has an annual meeting. It also publishes the Journal of the Antique Telescope Society and has an active email list. The American astronomer Michael D. Reynolds was the President of the Antique Telescope Society. == References == == External links == Antique Telescope Society website Antique Telescope Society on Facebook


id: aragoscope-20260505-0
file: data/en.wikipedia.org/wiki/Aragoscope-0.md
category: reference
title: Aragoscope
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Aragoscope
date_saved: 2026-05-05T09:46:57.331564+00:00
instance: kb-cron
parent: aragoscope-20260505-0
summary:
An Aragoscope is a telescope design based on diffraction around the edge of an occluding disc, named after French scientist François Arago. == Concept == The light diffracted around the edge of a perfectly circular occluder interferes constructively at the central axis, producing a bright spot known as the Arago spot. The resolution at that point would be equal to the resolution of a conventional lens with the same size as the occluder, although the light would be much less intense. On this basis it would be possible to create a telescope by placing a suitable disc in space accompanied by a separate telescope some distance away along its axis. This concept has been explored by NASA and received Phase One funding in June 2014 by the NASA Innovative Advanced Concepts (NIAC) program. It is important to note that this is a very different approach from that taken by another NASA project, the New Worlds Mission, which aims to use an occluder with "petals", otherwise known as a starshade, specifically designed to avoid diffraction onto the central axis. == See also == Arago telescope, a 38 cm (15 inch) refractor at Paris Observatory's east tower Zone plate == References ==


id: astrograph-20260505-0
file: data/en.wikipedia.org/wiki/Astrograph-0.md
category: reference
title: Astrograph
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Astrograph
date_saved: 2026-05-05T09:46:58.538503+00:00
instance: kb-cron
parent: astrograph-20260505-0
summary:
An astrograph (or astrographic camera) is a telescope designed for the sole purpose of astrophotography. Astrographs are mostly used in wide-field astronomical surveys of the sky and for detection of objects such as asteroids, meteors, and comets. Improvements in photography in the middle 19th century led to designs dedicated to astrophotography, and they were also popular in the 20th century. As in other photography, chemicals were used that respond to light, recorded on a glass photographic plate or sometimes on photographic film. Many observatories of this period used an astrograph, beside instruments like the transit telescope, great refractors, and chronometers, or instruments for observing the Sun. Astrographs were often used to make surveys of the night sky, and one of the famous projects was Carte du Ciel. Discoveries using an astrograph include then-planet Pluto. Rather than looking through the telescope, it was discovered by using a blink comparator with images taken by an astrograph. By the late 20th century, electronic detectors became more common with the data being stored electronically. == Design == Most research telescopes in this class are refractors, although there are many (usually larger) reflecting designs such as the Ritchey-Chrétien and catadioptrics such as the Schmidt camera.


id: astroscan-20260505-0
file: data/en.wikipedia.org/wiki/Astroscan-0.md
category: reference
title: Astroscan
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Astroscan
date_saved: 2026-05-05T09:46:59.692385+00:00
instance: kb-cron
parent: astroscan-20260505-0
summary:
The Astroscan was a wide-field 4+1⁄8 in (10 cm) clear-inch diameter reflecting telescope, originally produced by the Edmund Scientific Corporation, that was for sale from 1976 to 2013. == Design == The Astroscan had a Newtonian reflector layout with a 4+1⁄8 in (10 cm) clear-inch diameter f/4.2 aluminized and overcoated borosilicate glass parabolic primary mirror with a focal length of 17+1⁄2 inches (44 cm). The telescope's secondary mirror was mounted on a flat optical window at the front of the tube. Edmund designer Norman Sperling and optical engineer Mike Simmons came up with the basic design and Peter Bressler Design Associates did the detailed work on this simple introductory telescope. Rather than using a more traditional equatorial or altazimuth mount the Astroscan features a spherical housing around the primary reflector which sat in a cast aluminum cradle. The design was durable and allowed for simple operation by novice amateur astronomers; it won an Industrial Design Award in 1976. The telescope body was made from high impact acrylonitrile butadiene styrene (ABS) plastic and was equipped with a carrying strap to aid portability. Because it was targeted at the novice market the telescope had its limitations: The general design was for low


id: atmosphere-and-telescope-simulator-20260505-0
file: data/en.wikipedia.org/wiki/Atmosphere_and_Telescope_Simulator-0.md
category: reference
title: Atmosphere and Telescope Simulator
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Atmosphere_and_Telescope_Simulator
date_saved: 2026-05-05T09:47:00.864770+00:00
instance: kb-cron
parent: atmosphere-and-telescope-simulator-20260505-0
summary:
Atmosphere and Telescope Simulators for astronomy education, are used because time in science-worthy class telescopes are generally expensive and difficult to obtain. Telescope facilities are often uncomfortable for operators working for long periods of time. In addition, Atmosphere and Telescope Simulators can be used to test new adaptive optics systems before using them on real telescopes. Researchers have expressed the need for a laboratory tool which could provide better and cheaper accessibility than a real telescope, and better characterization than computer simulations. A LED based illumination system in which five Galilean collimation systems have been used is reported on. It is part of a turbulence simulator for the evaluation of on ground telescopes instrumentation developed by INTA (optics) and LIDAX (opto-mechanics) for the IAC called IACATS. The IACATS instrument simulates a scene consisting of a set of different binary stars simulating the required angular separation between them, and their spectral characteristics. As a result, a visible and infrared multi-spectral illumination system has been integrated as a part of the turbulence simulator. A wave front sensor enables to evaluate the deformation that the phase plates, or the simulated turbulence, produce in the wave front coming from the illumination system and star


id: automated-patrol-telescope-20260505-0
file: data/en.wikipedia.org/wiki/Automated_Patrol_Telescope-0.md
category: reference
title: Automated Patrol Telescope
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Automated_Patrol_Telescope
date_saved: 2026-05-05T09:47:02.037691+00:00
instance: kb-cron
parent: automated-patrol-telescope-20260505-0
summary:
The Automated Patrol Telescope (APT) was a wide-field CCD imaging telescope, operated by the University of New South Wales at Siding Spring Observatory, Australia. The telescope activated in June 1989. This was one of four (4) ROTSE telescopes around the World to detect Gamma ray bursts, with telescopes positioned in Australia, Namibia, Turkey, and Texas. The telescope was designed for robotic use, with 45 cm aperture. The telescope was converted for computer controlled operation and CCD imaging from an older retired Baker-nunn camera. This is a type of modified Schmidt canera. The telescope has a field of view of 5 degrees by 5 degrees. == See also == List of telescopes of Australia Lists of telescopes == References == == Further reading == Preliminary results from the Automated Patrol Telescope CCD camera (1990) == External links == Automated Patrol Telescope (APT) on the internet


id: automated-planet-finder-20260505-0
file: data/en.wikipedia.org/wiki/Automated_Planet_Finder-0.md
category: reference
title: Automated Planet Finder
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Automated_Planet_Finder
date_saved: 2026-05-05T09:47:03.209030+00:00
instance: kb-cron
parent: automated-planet-finder-20260505-0
summary:
The Automated Planet Finder (APF) Telescope a.k.a. Rocky Planet Finder, is a fully robotic 2.4-meter optical telescope at Lick Observatory, situated on the summit of Mount Hamilton, east of San Jose, California, USA. It is designed to search for extrasolar planets in the range of five to twenty times the mass of the Earth. The instrument will examine about 10 stars per night. Over the span of a decade, the telescope is expected to study 1,000 nearby stars for planets. Its estimated cost was $10 million. The total cost-to-completion of the APF project was $12.37 million. First light was originally scheduled for 2006, but delays in the construction of the major components of the telescope pushed this back to August 2013. It was commissioned in August 2013. The telescope uses high-precision radial velocity measurements to measure the gravitational reflex motion of nearby stars caused by the orbiting of planets. The design goal is to detect stellar motions as small as one meter per second, comparable to a slow walking speed. The main targets will be stars within about 100 light years of the Earth. Early tests show that the performance of the Ken and Gloria Levy Doppler Spectrometer is meeting


id: bahtinov-mask-20260505-0
file: data/en.wikipedia.org/wiki/Bahtinov_mask-0.md
category: reference
title: Bahtinov mask
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Bahtinov_mask
date_saved: 2026-05-05T09:47:04.393446+00:00
instance: kb-cron
parent: bahtinov-mask-20260505-0
summary:
The Bahtinov mask is a device used to focus small astronomical telescopes accurately. Although masks have long been used as focusing aids, the distinctive pattern was invented by Russian amateur astrophotographer Pavel Bahtinov (Russian: Павел Бахтинов) in 2005. Precise focusing of telescopes and astrographs is critical to performing astrophotography. The telescope is pointed at a bright star, and a mask is placed in front of the telescope's objective (or in front of the aperture). The mask consists of three separate grids, positioned in such a way that the grids produce three angled diffraction spikes at the focal plane of the instrument for each bright image element. As the instrument's focus is changed, the central spike appears to move from one side of the star to the other. In reality, all three spikes move, but the central spike moves in the opposite direction to the two spikes forming the "X". Optimal focus is achieved when the middle spike is centered between the other two spikes. Small deviations from optimal focus are easily visible. For astrophotography, a digital image can be analyzed by software to locate the alignment of the spikes to sub-pixel resolution. The direction of this displacement indicates the direction


id: birmingham-solar-oscillations-network-20260505-0
file: data/en.wikipedia.org/wiki/Birmingham_Solar_Oscillations_Network-0.md
category: reference
title: Birmingham Solar Oscillations Network
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Birmingham_Solar_Oscillations_Network
date_saved: 2026-05-05T09:47:05.609315+00:00
instance: kb-cron
parent: birmingham-solar-oscillations-network-20260505-0
summary:
The Birmingham Solar Oscillations Network (BiSON) consists of a network of six remote solar observatories monitoring low-degree solar oscillation modes. It is operated by the High Resolution Optical Spectroscopy group of the School of Physics and Astronomy at the University of Birmingham, UK, in collaboration with Sheffield Hallam University, UK. They are funded by the Science and Technology Facilities Council (STFC). The BiSON has been collecting data continuously on solar oscillations since 1976, making it the longest running helioseismology network with data covering three solar cycles. == Team == === Academic staff === Professor Yvonne Elsworth (Head of project) Professor Bill Chaplin === Research staff === Anne-Marie Broomhall — Helioseismology Andrea Miglio Steven Hale === Technical staff === Mr Ian Barnes — Electronics Mr Barry Jackson — Mechanics == Remote observatories == BiSON operates automated resonant scattering spectrometers in astronomical domes or mirror fed systems. The network was established in 1976 with two permanent stations; the addition of several more sites culminated with the addition of a sixth in 1992. The current sites are: Mount Wilson Observatory, California, USA Las Campanas Observatory, Region IV, Chile Observatorio del Teide, Tenerife, Canary Islands, Spain South African Astronomical Observatory, Sutherland, South Africa OTC


id: carey-mask-20260505-0
file: data/en.wikipedia.org/wiki/Carey_mask-0.md
category: reference
title: Carey mask
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Carey_mask
date_saved: 2026-05-05T09:47:06.765661+00:00
instance: kb-cron
parent: carey-mask-20260505-0
summary:
A Carey mask (named after the inventor, George F. Carey) is a focusing aid for astronomical telescopes. The mask is in the form of a thin card or sheet that is placed over the front aperture of the telescope. There are four series of slits in the mask which form a diffraction pattern in the image plane. In this example the two sets of slits on the left are angled at 12 degrees to each other. Those on the right are angled at 10 degrees to each other. Different telescope and imaging combinations may require slightly different angles. The diffraction pattern caused by the left hand slits will be in the form of an 'X'. The right hand slits will also form an 'X' shape, but the lines forming the 'X' will cross at a narrower angle. When perfect focus is achieved the two 'X's will be superimposed and be perfectly symmetrical. Any slight error in focus will cause the 'X's to be offset, and this is very noticeable to the naked eye. In the example images below, focus error is obvious in the first two images. The third image is very close to perfect focus as shown by the


id: chabot-space-and-science-center-20260505-0
file: data/en.wikipedia.org/wiki/Chabot_Space_and_Science_Center-0.md
category: reference
title: Chabot Space and Science Center
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Chabot_Space_and_Science_Center
date_saved: 2026-05-05T09:47:07.984471+00:00
instance: kb-cron
parent: chabot-space-and-science-center-20260505-0
summary:
Chabot Space and Science Center (), located in Oakland, California, is a center for learning in Earth and space science, which features interactive exhibits, planetariums, a large screen theater, hands-on activities, and three powerful telescopes. The center is the continuation and expansion of a public observatory that has served San Francisco Bay Area schools and citizens with astronomy and science education programs since 1883. It is named after the father of hydraulic mining and benefactor of the original Oakland Observatory, Anthony Chabot. Since 2000, the center has been located on the western border of Redwoods Regional Park and has partnered with the National Aeronautics and Space Administration, hosting the NASA Ames Visitor Center. == History == The institution began in 1883 as the Oakland Observatory, through a gift from Anthony Chabot to the City of Oakland. The original Oakland Observatory was located near downtown Oakland and provided public telescope viewing for the community. For decades, it also served as the official timekeeping station for the entire Bay Area, measuring time with its transit telescope. The observatory moved to its Mountain Boulevard location near the current State Route 13 (37°47′13″N 122°10′42″W - telescope domes visible in satellite view) in 1915 due


id: comet-seeker-20260505-0
file: data/en.wikipedia.org/wiki/Comet_seeker-0.md
category: reference
title: Comet seeker
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Comet_seeker
date_saved: 2026-05-05T09:47:09.154621+00:00
instance: kb-cron
parent: comet-seeker-20260505-0
summary:
A comet seeker is a type of small telescope adapted especially to searching for comets: commonly of short focal length and large aperture, in order to secure the greatest brilliancy of light. This style of telescope was used to discover the asteroid 9 Metis in 1848. == Design == A comet seeker telescope is a type of optical device that is known for having a short focal length but a wide field of view. == Examples == A comet seeker with about 3.9 inch aperture was installed at the United States Naval Observatory in 1843, and later transferred to the Smithsonian Museum in 1866. It had an aperture of 4 inches (10.2 cm) and was made by Utzschneider & Fraunhofer in Munich. This was operated as part of suite of several other instruments including a larger refractor on an equatorial mounting, a meridian transit, mural circle, etc. Markree Observatory added a 3-inch aperture Comet Seeker on an equatorial mount by Ertel. It was ordered in 1842, and in place until 1874. The Markree Comet Seeker was used to discover 9 Metis in April 1848. It was discovered by Edward Cooper's assistant Andrew Graham, who worked at that observatory until 1860.


id: compton-telescope-20260505-0
file: data/en.wikipedia.org/wiki/Compton_telescope-0.md
category: reference
title: Compton telescope
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Compton_telescope
date_saved: 2026-05-05T09:47:10.283052+00:00
instance: kb-cron
parent: compton-telescope-20260505-0
summary:
A Compton telescope (also known as Compton camera or Compton imager) is a gamma-ray detector which utilizes Compton scattering to determine the origin of the observed gamma rays. Compton cameras are usually applied to detect gamma rays in the energy range where Compton scattering is the dominating interaction process, from a few hundred keV to several MeV. They are applied in fields such as astrophysics, nuclear medicine, and nuclear threat detection. == Principle of operation == The Compton telescope consists of two layers of Compton scattering detectors spaced apart (1.5 m in the case of COMPTEL). A Compton scattering event results in an electron and a photon. Each layer detects the position of a event and the energy of an electron resulting from the Compton event. In addition, the time between events in the upper and lower layers is measured. When the time between two events matches the time it takes for the photon to travel from the upper to lower level, the events are accepted for a image. The direction of the original gamma ray is unknown but the angle of the second photon and the energies of the two electrons allow the angle between the first and second


id: cophasing-20260505-0
file: data/en.wikipedia.org/wiki/Cophasing-0.md
category: reference
title: Cophasing
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Cophasing
date_saved: 2026-05-05T09:47:11.478276+00:00
instance: kb-cron
parent: cophasing-20260505-0
summary:
In astronomy, the term cophasing or phasing describes the process of controlling the individual segments in a segmented mirror or a telescope so that the segments form a larger composite mirroring surface. Cophasing implies precise, active control of three degrees of freedom of each individual segment mirror: translation along the optical axis (piston) and rotation about two axes perpendicular to the optical axis (tip-tilt). Each segment of the segmented telescope is a solid body having 6 degrees of freedom exposed to the gravitation force, wind blowing, and other mechanical forces. If the position of each segment is not controlled the resolution of the whole telescope will be the same as if telescope had the diameter equal to the size of one segment. To achieve a resolution commensurable with that of a monolithic telescope of the same diameter the segmented surface must be controlled with a precision better than λ / 40 {\displaystyle \lambda /40} surface rms. Projects for future extremely large telescopes (ELTs) generally depend on the use of a segmented primary mirror. While the basic technologies required for segmented telescopes have been demonstrated for the 10m Keck telescope or GTC telescope, ELTs of diameters from 50 to 100 m


id: copyscope-20260505-0
file: data/en.wikipedia.org/wiki/Copyscope-0.md
category: reference
title: Copyscope
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Copyscope
date_saved: 2026-05-05T09:47:12.646818+00:00
instance: kb-cron
parent: copyscope-20260505-0
summary:
A copyscope is type of refracting telescope that can be made by hand rather than bought in which the objective lens comes from an old photocopy machine, hence the origin of the name. The lenses usually come from defective or old photocopiers, allowing for the objective to be obtained for free or at a low cost. They are usually modest diameter lenses, ranging from 50mm to 60mm, of short focal length, good for use in a portable, wide-field telescope, but unsuitable for higher magnifications. Given the use of good components, however, a copyscope can become a rich-field instrument capable of reaching many extended objects and even star fields. == History == The way in which copyscopes are constructed was first shown and explained in the May 1986 issue of Astronomy Magazine by Ken Bird. Surplus photocopier lenses from 200 to 300 mm focal length along with PVC pipe components for the tube and lens holder were used to build the copyscope described in the magazine. == Construction == Copyscopes usually use an objective lens sourced from a photocopier. Usually 50mm to 60mm in diameter, these lenses operate at low f/numbers (f-ratio of around f4 to f6) but cover a large


id: coud-spectrograph-20260505-0
file: data/en.wikipedia.org/wiki/Coudé_Spectrograph-0.md
category: reference
title: Coudé Spectrograph
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Coudé_Spectrograph
date_saved: 2026-05-05T09:47:14.150442+00:00
instance: kb-cron
parent: coud-spectrograph-20260505-0
summary:
The Coudé Spectrograph was an instrument attached to the coudé focus of the ESO 1.52-metre telescope (coudé is the French word for elbow). Three cameras equipped with photographic plates as detectors were available. It has two cameras working at f/6 and f/14. Dispersions from 1A/mm to 18a/mm are available with a selection of three gratings, each with ruled areas of 20 x 30 cm. The Coudé Spectrograph was installed at the coudé focus of the ESO 1.52-metre telescope at the La Silla Observatory in May 1969. It was decommissioned from the ESO 1.52-metre telescope in mid 1980s. == References == == External links == Diagram of a Coudé spectrograph.


id: craig-telescope-20260505-0
file: data/en.wikipedia.org/wiki/Craig_telescope-0.md
category: reference
title: Craig telescope
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Craig_telescope
date_saved: 2026-05-05T09:47:15.322173+00:00
instance: kb-cron
parent: craig-telescope-20260505-0
summary:
The Craig telescope was a large telescope built in the 1850s, and while much larger than previous refracting telescopes, it had some problems that hampered its use. Its unique design and potential caused a great deal of excitement in its day. The telescope was ready in August 1852 and was visited by William Parsons, 3rd Earl of Rosse, famous for the Leviathan of Parsonstown, a reflecting telescope and the largest telescope of this age with a six-foot mirror. == Telescope == It was the largest refracting telescope (a telescope with a lens) in the world from 1852 to 1857, erected in south London, England. It was a great refractor, a large refracting telescope with an achromatic doublet with an aperture of 61 cm (2 feet or 24 inches) and was completed in 1852 on Wandsworth Common and dismantled around 1857 (although the brick tower probably survived until 1870). It had a focal length of 76–83 feet. It was named after the Reverend John Craig, who spent a small fortune on it, producing a uniquely designed telescope with nearly double the aperture of the next largest refracting telescopes, making it the largest refracting telescope in the World for the better part


id: dark-energy-spectroscopic-instrument-20260505-0
file: data/en.wikipedia.org/wiki/Dark_Energy_Spectroscopic_Instrument-0.md
category: reference
title: Dark Energy Spectroscopic Instrument
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Dark_Energy_Spectroscopic_Instrument
date_saved: 2026-05-05T09:47:16.561008+00:00
instance: kb-cron
parent: dark-energy-spectroscopic-instrument-20260505-0
summary:
The Dark Energy Spectroscopic Instrument (DESI) is a scientific research instrument for conducting spectrographic astronomical surveys of distant galaxies. Its main components are a focal plane containing 5,000 fiber-positioning robots, and a bank of spectrographs which are fed by the fibers. The instrument enables an experiment to probe the expansion history of the universe and the mysterious physics of dark energy. The main DESI survey started in May 2021. DESI sits at an elevation of 6,880 feet (2,100 m), where it has been retrofitted onto the Mayall Telescope on top of Kitt Peak in the Sonoran Desert, which is located 55 miles (89 km) from Tucson, Arizona, United States. The instrument is operated by the Lawrence Berkeley National Laboratory under funding from the U.S. Department of Energy's Office of Science. Construction of the instrument was principally funded by the U.S. Department of Energy's Office of Science, and by other numerous sources including the U.S. National Science Foundation, the British Science and Technology Facilities Council, France's Alternative Energies and Atomic Energy Commission, Mexico's National Council of Science and Technology, Spain's Ministry of Science and Innovation, by the Gordon and Betty Moore Foundation, by the Heising-Simons Foundation, and by collaborating institutions worldwide.


id: dark-energy-spectroscopic-instrument-20260505-1
file: data/en.wikipedia.org/wiki/Dark_Energy_Spectroscopic_Instrument-1.md
category: reference
title: Dark Energy Spectroscopic Instrument
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Dark_Energy_Spectroscopic_Instrument
date_saved: 2026-05-05T09:47:16.561008+00:00
instance: kb-cron
parent: dark-energy-spectroscopic-instrument-20260505-0
summary:
== Development == The DESI instrument implements a new highly multiplexed optical spectrograph on the Mayall Telescope. The new optical corrector design creates a very large, 8.0 square degree field of view on the sky, which combined with the new focal plane instrumentation weighs approximately 10 tonnes. The focal plane accommodates 5,000 small robotic fiber positioners on a 10.4 millimeter pitch. The entire focal plane can be reconfigured for the next exposure in less than two minutes while the telescope slews to the next field. The DESI instrument is capable of taking 5,000 simultaneous spectra over a wavelength range from 360 nm to 980 nm. The DESI project scope included construction, installation, and commissioning of the new wide-field corrector and corrector support structure for the telescope, the focal plane assembly with 5,000 robotic fiber positioners and ten guide/focus/alignment sensors, a 40-meter optical fiber cabling system that brings light from the focal plane to the spectrographs, ten 3-arm spectrographs, an instrument control system, and a data analysis pipeline. The instrument fabrication was managed by the Lawrence Berkeley National Laboratory and oversees operation of the experiment including a 600-person international scientific collaboration. Cost of construction was $56M from the US Department of


id: dark-energy-spectroscopic-instrument-20260505-2
file: data/en.wikipedia.org/wiki/Dark_Energy_Spectroscopic_Instrument-2.md
category: reference
title: Dark Energy Spectroscopic Instrument
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Dark_Energy_Spectroscopic_Instrument
date_saved: 2026-05-05T09:47:16.561008+00:00
instance: kb-cron
parent: dark-energy-spectroscopic-instrument-20260505-0
summary:
=== Early data release === On 13 June 2023 the DESI Early Data Release (EDR) was announced. The EDR contains spectra of nearly two million galaxies, quasars and stars. One early result of the EDR was announced in February 2023 and described a mass migration of stars into the Andromeda Galaxy. The EDR also revealed very distant quasars and very metal-poor stars. In 2025, a team led by Ragadeepika Pucha of the University of Arizona and the University of Utah reported in The Astrophysical Journal the discovery of the largest number of dwarf galaxies including 2,800 black holes (300 intermediate-mass black holes and 2,500 active black holes) from the EDR. ==== Possibly evolving dark energy levels ==== From the level of detail able to be observed, the largest 3-D map of the universe at this point has been created (2024). From this precise data, DESI Director Michael Levi stated:We’re also seeing some potentially interesting differences that could indicate that dark energy is evolving over time. Those may or may not go away with more data, so we’re excited to start analyzing our three-year dataset soon. === Data Release 1 (DR1) === Data Release 1 (DR1), published on 19 March 2025,


id: diffraction-limited-system-20260505-0
file: data/en.wikipedia.org/wiki/Diffraction-limited_system-0.md
category: reference
title: Diffraction-limited system
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Diffraction-limited_system
date_saved: 2026-05-05T09:47:17.785058+00:00
instance: kb-cron
parent: diffraction-limited-system-20260505-0
summary:
In optics, any optical instrument or system – a microscope, telescope, or camera – has a principal limit to its resolution due to the physics of diffraction. An optical instrument is said to be diffraction-limited if it has reached this limit of resolution performance. Other factors may affect an optical system's performance, such as lens imperfections or aberrations, but these are caused by errors in the manufacture or calculation of a lens, whereas the diffraction limit is the maximum resolution possible for a theoretically perfect, or ideal, optical system. The diffraction-limited angular resolution, in radians, of an instrument is proportional to the wavelength of the light being observed, and inversely proportional to the diameter of its objective's entrance aperture. For telescopes with circular apertures, the size of the smallest feature in an image that is diffraction limited is the size of the Airy disk. As one decreases the size of the aperture of a telescopic lens, diffraction proportionately increases. At small apertures, such as f/22, most modern lenses are limited only by diffraction and not by aberrations or other imperfections in the construction. For microscopic instruments, the diffraction-limited spatial resolution is proportional to the light wavelength, and to the numerical


id: diffraction-limited-system-20260505-1
file: data/en.wikipedia.org/wiki/Diffraction-limited_system-1.md
category: reference
title: Diffraction-limited system
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Diffraction-limited_system
date_saved: 2026-05-05T09:47:17.785058+00:00
instance: kb-cron
parent: diffraction-limited-system-20260505-0
summary:
In the case where the spread of the IRF is small with respect to the spread of the diffraction PSF, in which case the system may be said to be essentially diffraction limited (so long as the lens itself is diffraction limited). In the case where the spread of the diffraction PSF is small with respect to the IRF, in which case the system is instrument limited. In the case where the spread of the PSF and IRF are similar, in which case both impact the available resolution of the system. The spread of the diffraction-limited PSF is approximated by the diameter of the first null of the Airy disk, d / 2 = 1.22 λ N , {\displaystyle d/2=1.22\lambda N,\,} where λ {\displaystyle \lambda } is the wavelength of the light and N {\displaystyle N} is the f-number of the imaging optics, i.e., 2 N A → ( 2.44 N ) − 1 {\displaystyle 2\mathrm {NA} \rightarrow (2.44N)^{-1}} in the Abbe diffraction limit formula. For instance, for an f/8 lens ( N = 8 {\displaystyle N=8} and N A ≈ 2.5 % {\displaystyle \mathrm {NA} \approx 2.5\%} ) and for green light ( λ g = {\displaystyle \lambda _{g}=}


id: diffraction-limited-system-20260505-2
file: data/en.wikipedia.org/wiki/Diffraction-limited_system-2.md
category: reference
title: Diffraction-limited system
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Diffraction-limited_system
date_saved: 2026-05-05T09:47:17.785058+00:00
instance: kb-cron
parent: diffraction-limited-system-20260505-0
summary:
=== Near-field techniques === The diffraction limit is only valid in the far field as it assumes that no evanescent fields reach the detector. Various near-field techniques that operate less than ≈1 wavelength of light away from the image plane can obtain substantially higher resolution. These techniques exploit the fact that the evanescent field contains information beyond the diffraction limit which can be used to construct very high resolution images, in principle beating the diffraction limit by a factor proportional to how well a specific imaging system can detect the near-field signal. For scattered light imaging, instruments such as near-field scanning optical microscopes and nano-FTIR, which are built atop atomic force microscope systems, can be used to achieve up to 10-50 nm resolution. The data recorded by such instruments often requires substantial processing, essentially solving an optical inverse problem for each image. Metamaterial-based superlenses can image with a resolution better than the diffraction limit by locating the objective lens extremely close (typically hundreds of nanometers) to the object. In fluorescence microscopy the excitation and emission are typically on different wavelengths. In total internal reflection fluorescence microscopy a thin portion of the sample located immediately on the cover glass is excited


id: dioptrics-20260505-0
file: data/en.wikipedia.org/wiki/Dioptrics-0.md
category: reference
title: Dioptrics
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Dioptrics
date_saved: 2026-05-05T09:47:18.930263+00:00
instance: kb-cron
parent: dioptrics-20260505-0
summary:
Dioptrics is the branch of optics dealing with refraction, especially by lenses. In contrast, the branch dealing with mirrors is known as catoptrics. Telescopes that create their image with an objective that is a convex lens (refractors) are said to be "dioptric" telescopes. An early study of dioptrics was conducted by Ptolemy in relationship to the human eye as well as refraction in media such as water. The understanding of the principles of dioptrics was further expanded by Alhazen, considered the father of modern optics. == See also == Diopter/Dioptre (unit of measurement) Catoptrics (study of and optical systems utilizing reflection) Catadioptrics (study of and optical systems utilizing reflection and refraction) Optical telescope List of telescope types Image-forming optical system == References ==


id: equatorial-mount-20260505-0
file: data/en.wikipedia.org/wiki/Equatorial_mount-0.md
category: reference
title: Equatorial mount
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Equatorial_mount
date_saved: 2026-05-05T09:47:21.177742+00:00
instance: kb-cron
parent: equatorial-mount-20260505-0
summary:
An equatorial mount is a mount for instruments that compensates for Earth's rotation by having one rotational axis, called polar axis, parallel to the Earth's axis of rotation. This type of mount is used for astronomical telescopes and cameras. The advantage of an equatorial mount lies in its ability to allow the instrument attached to it to stay fixed on any celestial object with diurnal motion by driving one axis at a constant speed. Such an arrangement is called a sidereal drive or clock drive. Equatorial mounts achieve this by aligning their rotational axis with the Earth, a process known as polar alignment. == Astronomical telescope mounts == In astronomical telescope mounts, the equatorial axis (the right ascension) is paired with a second perpendicular axis of motion (known as the declination). The equatorial axis of the mount is often equipped with a motorized "clock drive", that rotates that axis one revolution every 23 hours and 56 minutes in exact sync with the apparent diurnal motion of the sky. They may also be equipped with setting circles to allow for the location of objects by their celestial coordinates. Equatorial mounts differ from mechanically simpler altazimuth mounts, which require variable speed motion


id: equatorial-platform-20260505-0
file: data/en.wikipedia.org/wiki/Equatorial_platform-0.md
category: reference
title: Equatorial platform
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Equatorial_platform
date_saved: 2026-05-05T09:47:22.364105+00:00
instance: kb-cron
parent: equatorial-platform-20260505-0
summary:
An equatorial platform or equatorial table is an equatorial telescope mount in the form of a specially designed platform that allows any device sitting on it to track astronomical objects in the sky on an equatorial axis. They are used to give equatorial tracking to any device sitting on them, from small cameras up to entire observatory buildings. They are often used with altazimuth mounted telescopes, such as the common Dobsonian telescope type, to overcome that type of mount's inability to track the night sky. With careful polar alignment sub-arc second precision CCD imaging is entirely possible. Roeser Observatory, Luxembourg (MPC observatory code 163) have contributed hundreds of astrometric measurements of Near Earth Asteroids to the Minor Planet Center using a home-built 20" Dobsonian telescope on an Osypowski equatorial platform. == Types == Many types of equatorial platform have been used over the years. The mid-1960s saw the introduction of the Russian AFU-75 satellite-tracking camera which consisted of a 3-axis altitude-altitude-azimuth mount mounted on a three-point equatorial platform. Two of the points were aligned on a polar axis while the third was a jackscrew actuator to drive the platform. This gave the mount a few minutes of equatorial tracking to


id: equatorial-room-20260505-0
file: data/en.wikipedia.org/wiki/Equatorial_room-0.md
category: reference
title: Equatorial room
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Equatorial_room
date_saved: 2026-05-05T09:47:23.513200+00:00
instance: kb-cron
parent: equatorial-room-20260505-0
summary:
An equatorial room, in astronomical observatories, is the room which contains an equatorial mounted telescope. It is usually referred to in observatory buildings that contain more than one type of instrument: for example buildings with an "equatorial room" containing an equatorial telescope and a "transit room" containing a transit telescope. Equatorial rooms tend to be large circular rooms to accommodate all the range of motion of a long telescope on an equatorial mount and are usually topped with a dome to keep out the weather. In some cases an observatory would move to a new location, or the equatorial telescope itself would be removed. The space would then be converted, for example, into use as a classroom or library. These peculiar rooms can sometimes be found in buildings at old colleges and towns, with their former use long forgotten. == References == Introduction To Orwell Park Observatory" by James Appleton == Further reading == George Frederick Chambers (1890), A Handbook of Descriptive and Practical Astronomy: Instruments and practical astronomy, Clarendon Press, p. 198 Sir Norman Lockyer (1886), "Detail of the Structure of the Observatory", Nature, XXXIII, Macmillan Journals Limited: 57


id: eyepiece-20260505-0
file: data/en.wikipedia.org/wiki/Eyepiece-0.md
category: reference
title: Eyepiece
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Eyepiece
date_saved: 2026-05-05T09:47:24.682125+00:00
instance: kb-cron
parent: eyepiece-20260505-0
summary:
An eyepiece, or ocular lens, is a type of lens that is attached to a variety of optical devices such as telescopes and microscopes. It is named because it is usually the lens that is closest to the eye when someone looks through an optical device to observe an object or sample. The objective lens or mirror collects light from an object or sample and brings it to focus creating an image of the object. The eyepiece is placed near the focal point of the objective to magnify this image to the eyes. (The eyepiece and the eye together make an image of the image created by the objective, on the retina of the eye.) The amount of magnification depends on the focal length of the eyepiece. An eyepiece consists of several "lens elements" in a housing, with a "barrel" on one end. The barrel is shaped to fit in a special opening of the instrument to which it is attached. The image can be focused by moving the eyepiece nearer and further from the objective. Most instruments have a focusing mechanism to allow movement of the shaft in which the eyepiece is mounted, without needing to manipulate the eyepiece


id: eyepiece-20260505-1
file: data/en.wikipedia.org/wiki/Eyepiece-1.md
category: reference
title: Eyepiece
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Eyepiece
date_saved: 2026-05-05T09:47:24.682125+00:00
instance: kb-cron
parent: eyepiece-20260505-0
summary:
f E {\displaystyle \ f_{\mathsf {E}}\ } is the focal length of the eyepiece. Magnification increases, therefore, when the focal length of the eyepiece is shorter or the focal length of the objective is longer. For example, a 25 mm eyepiece in a telescope with a 1200 mm focal length would magnify objects 48 times. A 4 mm eyepiece in the same telescope would magnify 300 times. Amateur astronomers tend to refer to telescope eyepieces by their focal length in millimeters. These typically range from about 3 mm to 50 mm. Some astronomers, however, prefer to specify the resulting magnification power rather than the focal length. It is often more convenient to express magnification in observation reports, as it gives a more immediate impression of what view the observer actually saw. Due to its dependence on properties of the particular telescope in use, however, magnification power alone is meaningless for describing a telescope eyepiece. For a compound microscope the corresponding formula is M A = D ⋅ D E O f E ⋅ f O = D f E ⋅ D E O f O {\displaystyle \ M_{\mathsf {A}}={\frac {~~~D\ \cdot \ D_{\mathsf {EO}}\ }{\ f_{\mathsf {E}}\ \cdot \ f_{\mathsf


id: eyepiece-20260505-2
file: data/en.wikipedia.org/wiki/Eyepiece-2.md
category: reference
title: Eyepiece
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Eyepiece
date_saved: 2026-05-05T09:47:24.682125+00:00
instance: kb-cron
parent: eyepiece-20260505-0
summary:
True or Telescope's field of view For a telescope or binocular, the actual angular size of the span of sky that can be seen through a particular eyepiece, used with a particular telescope, producing a specific magnification. It ranges typically between 0.1–2 degrees. For a microscope, the actual width of the visible sample on the slide or sample tray, usually given in millimeters, but sometimes given as angular measure, like a telescope. For binoculars it is expressed as the actual field width in feet or in meters at some standard distance (typically either 100 feet or 30 meters, which are very nearly the same: 30 m is only a 2% smaller than 100 feet). Apparent or Eye's field of view For telescopes, microscopes, or binoculars, the apparent field of view is a measure of the angular size of the image seen by the eye, through the eyepiece. In other words, it is how large the image appears (as distinct from the magnification). Unless there is vignetting by the telescope's or microscope's body tube, this is constant for any given eyepiece with a fixed focal length, and may be used to calculate what the true field of view will be when


id: eyepiece-20260505-3
file: data/en.wikipedia.org/wiki/Eyepiece-3.md
category: reference
title: Eyepiece
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Eyepiece
date_saved: 2026-05-05T09:47:24.682125+00:00
instance: kb-cron
parent: eyepiece-20260505-0
summary:
This formula also indicates that, for an eyepiece design with a given apparent field of view, the barrel diameter will determine the maximum focal length possible for that eyepiece, as no field stop can be larger than the barrel itself. For example, a Plössl with 45° apparent field of view in a 1.25 inch barrel would yield a maximum focal length of 35 mm. Anything longer requires larger barrel or the view is restricted by the edge, effectively making the field of view less than 45°. === Barrel diameter === Eyepieces for telescopes and microscopes are usually interchanged to increase or decrease the magnification, and to enable the user to select a type with certain performance characteristics. To allow this, eyepieces come in standardized "Barrel diameters". ==== Telescope eyepieces ==== There are six standard barrel diameters for telescopes. The barrel sizes (usually expressed in inches) are: 0.965 inch (24.5 mm) – This is the smallest standard barrel diameter and is usually found in retail toy store and shopping mall telescopes. Many of these eyepieces that come with such telescopes are plastic, and some even have plastic lenses. High-end telescope eyepieces with this barrel size are no longer manufactured, but you


id: eyepiece-20260505-4
file: data/en.wikipedia.org/wiki/Eyepiece-4.md
category: reference
title: Eyepiece
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Eyepiece
date_saved: 2026-05-05T09:47:24.682125+00:00
instance: kb-cron
parent: eyepiece-20260505-0
summary:
A simple convex lens placed after the focus of the objective lens presents the viewer with a magnified inverted image. This configuration may have been used in the first refracting telescopes from the Netherlands and was proposed as a way to have a much wider field of view and higher magnification in telescopes in Johannes Kepler's 1611 book Dioptrice. Since the lens is placed after the focal plane of the objective it also allowed for use of a micrometer at the focal plane (used for determining the angular size and/or distance between objects observed). === Huygens === Huygens eyepieces consist of two plano-convex lenses with the plane sides towards the eye separated by an air gap. The lens closest to an observer's eye is called the eye lens and the other lens is called field lens. The focal plane is located between the two lenses. It was invented by Christiaan Huygens in the late 1660s and was the first compound (multi-lens) eyepiece. Huygens discovered that two air spaced lenses can be used to make an eyepiece with zero transverse chromatic aberration. If the lenses are made of glass of the same Abbe number, to be used with a relaxed eye


id: eyepiece-20260505-5
file: data/en.wikipedia.org/wiki/Eyepiece-5.md
category: reference
title: Eyepiece
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Eyepiece
date_saved: 2026-05-05T09:47:24.682125+00:00
instance: kb-cron
parent: eyepiece-20260505-0
summary:
=== Orthoscopic or "Abbe" === The 4-element orthoscopic eyepiece consists of a plano-convex singlet eye lens and a cemented convex-convex triplet field lens achromatic field lens. This gives the eyepiece a nearly perfect image quality and good eye relief, but a narrow apparent field of view — about 40°–45°. It was invented by Ernst Abbe in 1880. It is called "orthoscopic" or "orthographic" because of its low degree of distortion and is also sometimes called an "ortho" or "Abbe". Until the advent of multicoating and the popularity of the Plössl, orthoscopic eyepieces were the most popular design for telescope eyepieces. Even today these eyepieces are considered good eyepieces for planetary and lunar viewing. They are preferred for reticle eyepieces, since they are one of the wide-field, long eye-relief designs with an external focal plane; slowly being supplanted by the König. Due to their low degree of distortion and the corresponding globe effect, they are less suitable for applications which require an extensive panning of the instrument. === Monocentric === A Monocentric is an achromatic triplet lens with two pieces of crown glass cemented on both sides of a flint glass element. The elements are thick, strongly curved, and their surfaces


id: eyepiece-20260505-6
file: data/en.wikipedia.org/wiki/Eyepiece-6.md
category: reference
title: Eyepiece
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Eyepiece
date_saved: 2026-05-05T09:47:24.682125+00:00
instance: kb-cron
parent: eyepiece-20260505-0
summary:
Invented by Albert Nagler and patented in 1979, the Nagler eyepiece is a design optimized for astronomical telescopes to give an ultra-wide field of view (82°) that has good correction for astigmatism and other aberrations. Introduced in 2007, the Ethos is an enhanced ultra-wide field design developed principally by Paul Dellechiaie under Albert Nagler's guidance at TeleVue Optics and claims a 100–110° AFOV. This is achieved using exotic high-index glass and up to eight optical elements in four or five groups; there are several similar designs called the Nagler, Nagler type 2, Nagler type 4, Nagler type 5, and Nagler type 6. The newer Delos design is a modified Ethos design with a FOV of 'only' 72 degrees but with a long 20 mm eye relief. The number of elements in a Nagler makes them seem complex, but the idea of the design is fairly simple: every Nagler has a negative doublet field lens, which increases magnification, followed by several positive groups. The positive groups, considered separate from the first negative group, combine to have long focal length, and form a positive lens. That allows the design to take advantage of the many good qualities of low power lenses. In


id: farside-telescope-20260505-0
file: data/en.wikipedia.org/wiki/FARSIDE_telescope-0.md
category: reference
title: FARSIDE telescope
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/FARSIDE_telescope
date_saved: 2026-05-05T09:47:25.858959+00:00
instance: kb-cron
parent: farside-telescope-20260505-0
summary:
FARSIDE (Farside Array for Radio Science Investigations of the Dark Ages and Exoplanets) is a concept for a low-frequency interferometric array that would be placed on the farside of the Moon. == FarView == FarView is another concept for a 20x20 km radio observatory with a total collecting area of 400 kilometers that would also be located on the Moon's far side. == References ==


id: first-light-astronomy-20260505-0
file: data/en.wikipedia.org/wiki/First_light_(astronomy)-0.md
category: reference
title: First light (astronomy)
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/First_light_(astronomy)
date_saved: 2026-05-05T09:47:26.973345+00:00
instance: kb-cron
parent: first-light-astronomy-20260505-0
summary:
In astronomy, first light is the first practical use of a new instrument, typically a telescope to take an astronomical image after it has been constructed. This is often not the first viewing using the telescope because optical tests have likely been performed to adjust the components. == See also == First light (cosmology) == References ==


id: foucault-knife-edge-test-20260505-0
file: data/en.wikipedia.org/wiki/Foucault_knife-edge_test-0.md
category: reference
title: Foucault knife-edge test
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Foucault_knife-edge_test
date_saved: 2026-05-05T09:47:28.166765+00:00
instance: kb-cron
parent: foucault-knife-edge-test-20260505-0
summary:
The Foucault knife-edge test is an optical test to accurately measure the shape of concave curved mirrors. It is commonly used by amateur telescope makers for figuring primary mirrors in reflecting telescopes. It uses a relatively simple, inexpensive apparatus compared to other testing techniques. == Overview == The Foucault knife-edge test was described in 1858 by French physicist Léon Foucault as a way to measure conic shapes of optical mirrors. It measures mirror surface dimensions by reflecting light into a knife edge at or near the mirror's centre of curvature. In doing so, it only needs a tester which in its most basic 19th century form consists of a light bulb, a piece of tinfoil with a pinhole in it, and a razor blade to create the knife edge. The testing device is adjustable along the X-axis (knife cut direction) across the Y-axis (optical axis), and is usually equipped with measurable adjustment to 0.001 inch (25 μm) or better along lines parallel to the optical axis. The test can measure errors in a mirror's curvature to fractions of wavelengths of light (or Angstroms, millionths of an inch, or nanometers). == Foucault test basics == Foucault testing is commonly used by


id: galaxy-h-alpha-fabry-perot-system-20260505-0
file: data/en.wikipedia.org/wiki/Galaxy_H-Alpha_Fabry-Perot_System-0.md
category: reference
title: Galaxy H-Alpha Fabry-Perot System
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Galaxy_H-Alpha_Fabry-Perot_System
date_saved: 2026-05-05T09:47:29.348978+00:00
instance: kb-cron
parent: galaxy-h-alpha-fabry-perot-system-20260505-0
summary:
The Galaxy Hα Fabry-Perot System for WHT (GHaFaS) is an astronomical instrument installed on the 4.2 metre William Herschel Telescope (WHT) at Roque de los Muchachos Observatory on the Canary island of La Palma. First light was on 6 July 2007. Its name is a play on the acronym: Galaxy Hα Fabry-Perot System and the Spanish word "gafas" meaning spectacles. It produces maps, in intensity and velocity, of extended objects in the sky (which could be external galaxies, star forming regions in the Galaxy, planetary nebulae, or supernova remnants, as examples), which radiate in the H-alpha line, emitted by ionized hydrogen in interstellar space. It can also be used for a variety of other lines. The possibility to detect the emission line of interstellar neutral hydrogen at 21 centimeters wavelength revolutionized astronomy in the second half of the 20th century, as a powerful tool to explore the structure and evolution of galaxies and the star formation within them. A second revolution came, when, at millimetre wavelengths, molecular hydrogen could be detected and measured in directly using, above all, the emission from the lines of the CO molecule. Surprisingly, the emission from the third phase of interstellar hydrogen, the ionized phase,


id: goto-telescopes-20260505-0
file: data/en.wikipedia.org/wiki/GoTo_(telescopes)-0.md
category: reference
title: GoTo (telescopes)
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/GoTo_(telescopes)
date_saved: 2026-05-05T09:47:30.542717+00:00
instance: kb-cron
parent: goto-telescopes-20260505-0
summary:
In amateur astronomy, "GoTo" refers to a type of telescope mount and related software that can automatically point a telescope at astronomical objects that the user selects. Both axes of a GoTo mount are driven by a motor and controlled by a computer. It may be either a microprocessor-based integrated controller or an external personal computer. This differs from the single-axis semi-automated tracking of a traditional clock-drive equatorial mount. The user can command the mount to point the telescope to the celestial coordinates that the user inputs, or to objects in a pre-programmed database including ones from the Messier catalogue, the New General Catalogue, and even major Solar System bodies (the Sun, Moon, and planets). Like a standard equatorial mount, equatorial GoTo mounts can track the night sky by driving the right ascension axis. Since both axes are computer controlled, GoTo technology also allows telescope manufacturers to add equatorial tracking to mechanically simpler altazimuth mounts. == How a GoTo mount works == GoTo mounts are pre-aligned before use. When it is powered on, it may ask for the user's latitude, longitude, time, and date. It can also get this data from a GPS receiver connected to the telescope or built


id: greenland-telescope-20260505-0
file: data/en.wikipedia.org/wiki/Greenland_Telescope-0.md
category: reference
title: Greenland Telescope
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Greenland_Telescope
date_saved: 2026-05-05T09:47:31.746296+00:00
instance: kb-cron
parent: greenland-telescope-20260505-0
summary:
The Greenland Telescope is a radio telescope situated at the Pituffik Space Base in north-western Greenland. It will later be deployed at the Summit Station research camp, located at the highest point of the Greenland ice sheet at an altitude of 3,210 meters (10,530 feet). The telescope is an international collaboration between: The Academia Sinica Institute of Astronomy and Astrophysics (Taiwan) (project leaders) The Smithsonian Astrophysical Observatory of the Center for Astrophysics | Harvard & Smithsonian (United States) The National Radio Astronomy Observatory (United States) The Haystack Observatory of the Massachusetts Institute of Technology (United States) In 2011 the U.S. National Science Foundation gave the Smithsonian Astrophysical Observatory a 12-meter radio antenna that had been used as a prototype for the ALMA project in Chile. The antenna was to be deployed in Greenland. Deploying the telescope in the middle of Greenland is ideal for detecting certain radio frequencies. The telescope will be used to study the event horizons of black holes and to test how general relativity behaves in environments with extreme gravity. The Greenland Telescope will become part of the global network of telescopes that makes up the Event Horizon Telescope that will study supermassive black holes and explore


id: hale-telescope-20260505-0
file: data/en.wikipedia.org/wiki/Hale_Telescope-0.md
category: reference
title: Hale Telescope
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Hale_Telescope
date_saved: 2026-05-05T09:47:32.989856+00:00
instance: kb-cron
parent: hale-telescope-20260505-0
summary:
The Hale Telescope is a 200-inch (5.1 m), f/3.3 reflecting telescope at the Palomar Observatory in San Diego County, California, US, named after astronomer George Ellery Hale. With funding from the Rockefeller Foundation in 1928, he orchestrated the planning, design, and construction of the observatory, but with the project ending up taking 20 years he did not live to see its commissioning. The Hale was groundbreaking for its time, with double the diameter of the second-largest telescope, and pioneered many new technologies in telescope mount design and in the design and fabrication of its large aluminum coated "honeycomb" low thermal expansion Pyrex mirror. It was completed in 1949 and is still in active use. The Hale Telescope represented the technological limit in building large optical telescopes for over 30 years. It was the largest telescope in the world from its construction in 1949 until the Soviet BTA-6 was built in 1976, and the second largest until the construction of the Keck Observatory Keck 1 in Hawaii in 1993. == History == Hale supervised the building of the telescopes at the Mount Wilson Observatory with grants from the Carnegie Institution of Washington: the 60-inch (1.5 m) telescope in 1908 and the


id: hale-telescope-20260505-1
file: data/en.wikipedia.org/wiki/Hale_Telescope-1.md
category: reference
title: Hale Telescope
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Hale_Telescope
date_saved: 2026-05-05T09:47:32.989856+00:00
instance: kb-cron
parent: hale-telescope-20260505-0
summary:
The mirror was cast in a mold with 36 raised mold blocks (similar in shape to a waffle iron). This created a honeycomb mirror that cut the amount of Pyrex needed down from over 40 short tons (36 t) to just 20 short tons (18 t), making a mirror that would cool faster in use and have multiple "mounting points" on the back to evenly distribute its weight (note – see external links 1934 article for drawings). The shape of a central hole was also part of the mold so light could pass through the finished mirror when it was used in a Cassegrain configuration (a Pyrex plug for this hole was also made to be used during the grinding and polishing process). While the glass was being poured into the mold during the first attempt to cast the 200-inch mirror, the intense heat caused several of the molding blocks to break loose and float to the top, ruining the mirror. The defective mirror was used to test the annealing process. After the mold was re-engineered, a second mirror was successfully cast. After cooling several months, the finished mirror blank was transported by rail to Pasadena, California. Once in Pasadena


id: hartmann-mask-20260505-0
file: data/en.wikipedia.org/wiki/Hartmann_mask-0.md
category: reference
title: Hartmann mask
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Hartmann_mask
date_saved: 2026-05-05T09:47:34.180616+00:00
instance: kb-cron
parent: hartmann-mask-20260505-0
summary:
Hartmann mask is a tool to help focusing telescopes, mainly used by amateur astronomers. It is named after the German astronomer Johannes Franz Hartmann (1865–1936), who developed it around 1900. == History == Hartmann mask was invented as a tool to check the quality of large optical mirrors. It was especially useful for large non-spherical mirrors for telescopes. For example, the illustration on the right shows the Hartmann mask used to test the Hale Telescope five-meter primary mirror. In today's professional telescope making, it has been completely superseded by interferometric methods. == Theory and practice == Every part of a mirror or lens produces the same image as the whole optical element. The light is focused in the focal point. The light rays, however, go through different points of a plane before or behind the focus. This phenomenon can be used when focusing a telescope. The Hartmann mask is a simple opaque mask containing two or three holes. (This device is called a Hartmann mask if it has multiple holes, or a Scheiner disk if it has two holes.) The mask covers the aperture of the telescope. When the apparatus is out of focus, multiple images can be seen if


id: hatnet-project-20260505-0
file: data/en.wikipedia.org/wiki/HATNet_Project-0.md
category: reference
title: HATNet Project
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/HATNet_Project
date_saved: 2026-05-05T09:47:35.525770+00:00
instance: kb-cron
parent: hatnet-project-20260505-0
summary:
The Hungarian Automated Telescope Network (HATNet) project is a network of six small fully automated "HAT" telescopes. The scientific goal of the project is to detect and characterize extrasolar planets using the transit method. This network is used also to find and follow bright variable stars. The network is maintained by the Center for Astrophysics | Harvard & Smithsonian. The HAT acronym stands for Hungarian-made Automated Telescope, because it was developed by a small group of Hungarians who met through the Hungarian Astronomical Association. The project started in 1999 and has been fully operational since May 2001. == Equipment == The prototype instrument, HAT-1 was built from a 180 mm focal length and 65 mm aperture Nikon telephoto lens and a Kodak KAF-0401E chip of 512 × 768, 9 μm pixels. The test period was from 2000 to 2001 at the Konkoly Observatory in Budapest. HAT-1 was transported from Budapest to the Steward Observatory, Kitt Peak, Arizona, USA, in January 2001. The transportation caused serious damage to the equipment. Later built telescopes use Canon 11 cm diameter f/1.8L lenses for a wide-field of 8°×8°. It is a fully automated instrument with 2K x 2K Charge-coupled device (CCD) sensors. One HAT


id: hexapod-telescope-20260505-0
file: data/en.wikipedia.org/wiki/Hexapod-Telescope-0.md
category: reference
title: Hexapod-Telescope
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Hexapod-Telescope
date_saved: 2026-05-05T09:47:36.717215+00:00
instance: kb-cron
parent: hexapod-telescope-20260505-0
summary:
The Hexapod-Telescope (HPT) was a 1.5-metre (59 in) Ritchey-Chrétien optical telescope, that operated in 2006-2017 in the Cerro Armazones Observatory (OCA) in northern Chile, and is currently decommissioned. The notable feature of the HPT – and the reason for its name – was the design of its mount. Instead of the typical mounting where the telescope moves on two rotating axes, the mirror cell was supported by six extensible (variable-length) struts, an arrangement known as a Stewart platform. This configuration allowed the telescope to move in all six spatial degrees of freedom and provided strong structural integrity. Furthermore, the six-leg structure allowed for a very precise positioning and repeatability. The HPT could have been rotated ±45° around the optical axis in any position. The mount allowed observations up to 30° elevation. Additionally, by using carbon fiber composites, the HPT was lighter by a factor of ten than classical telescopes of the same aperture. As a result, the ratio of bearing pressure and its own weight was very high. The active primary mirror had a diameter of 1.5 meters and – with a thickness of only 50 mm – was mounted on 36 piezo actuators. The secondary mirror was also supported


id: history-of-the-telescope-20260505-0
file: data/en.wikipedia.org/wiki/History_of_the_telescope-0.md
category: reference
title: History of the telescope
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/History_of_the_telescope
date_saved: 2026-05-05T09:47:38.014297+00:00
instance: kb-cron
parent: history-of-the-telescope-20260505-0
summary:
The history of the telescope can be traced to before the invention of the earliest known telescope, which appeared in 1608 in the Netherlands, when a patent was submitted by Hans Lippershey, an eyeglass maker. Although Lippershey did not receive his patent, news of the invention soon spread across Europe. The design of these early refracting telescopes consisted of a convex objective lens and a concave eyepiece. Galileo improved on this design the following year and applied it to astronomy. In 1611, Johannes Kepler described how a far more useful telescope could be made with a convex objective lens and a convex eyepiece lens. By 1655, astronomers such as Christiaan Huygens were building powerful but unwieldy Keplerian telescopes with compound eyepieces. Isaac Newton is credited with building the first reflector in 1668 with a design that incorporated a small flat diagonal mirror to reflect the light to an eyepiece mounted on the side of the telescope. Laurent Cassegrain in 1672 described the design of a reflector with a small convex secondary mirror to reflect light through a central hole in the main mirror. The achromatic lens, which greatly reduced color aberrations in objective lenses and allowed for shorter and more


id: history-of-the-telescope-20260505-1
file: data/en.wikipedia.org/wiki/History_of_the_telescope-1.md
category: reference
title: History of the telescope
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/History_of_the_telescope
date_saved: 2026-05-05T09:47:38.014297+00:00
instance: kb-cron
parent: history-of-the-telescope-20260505-0
summary:
In 1655, the Dutch diplomat William de Boreel tried to solve the mystery of who invented the telescope. He had a local magistrate in Middelburg follow-up on Boreel's childhood and early adult recollections of a spectacle-maker named "Hans", who he remembered as the inventor of the telescope. The magistrate was contacted by a then-unknown claimant– the Middelburg spectacle-maker Johannes Zachariassen, who testified that his father– Zacharias Janssen, invented the telescope and the microscope as early as 1590. This testimony seemed convincing to Boreel, who now recollected that Zacharias and his father– Hans Martens, must have been who he remembered. Boreel's conclusion that Zacharias Janssen invented the telescope a little ahead of another spectacle maker, Hans Lippershey, was adopted by Pierre Borel in his 1656 book De vero telescopii inventore. Discrepancies in Boreel's investigation and Zachariassen's testimony (including Zachariassen misrepresenting his date of birth and role in the invention) has led some historians to consider this claim dubious. The "Janssen" claim would continue over the years and be added on to with Zacharias Snijder in 1841 presenting 4 iron tubes with lenses in them claimed to be 1590 examples of Janssen's telescope and historian Cornelis de Waard's 1906 claim that the


id: history-of-the-telescope-20260505-2
file: data/en.wikipedia.org/wiki/History_of_the_telescope-2.md
category: reference
title: History of the telescope
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/History_of_the_telescope
date_saved: 2026-05-05T09:47:38.014297+00:00
instance: kb-cron
parent: history-of-the-telescope-20260505-0
summary:
Galileo set himself to improving the telescope, producing telescopes of increased magnification. His first telescope had a 3x magnification, but he soon made instruments which magnified 8x, and finally, one nearly a meter long with a 37mm objective (which he would stop down to 16mm or 12mm) and a 23x magnification. With this last instrument, he began a series of astronomical observations in October or November 1609, observing the satellites of Jupiter, hills and valleys on the moon, the phases of Venus and spots on the sun (using the projection method rather than direct observation). Galileo noted that the revolution of the satellites of Jupiter, the phases of Venus, rotation of the sun and the tilted path its spots followed for part of the year pointed to the validity of the sun-centered Copernican system over other Earth-centered systems such as the one proposed by Ptolemy. Galileo's instrument was the first to be given the name "telescope". The name was invented by the Greek poet/theologian Giovanni Demisiani at a banquet held on April 14, 1611, by Prince Federico Cesi to make Galileo Galilei a member of the Accademia dei Lincei. The word was created from the Greek tele = 'far' and


id: history-of-the-telescope-20260505-3
file: data/en.wikipedia.org/wiki/History_of_the_telescope-3.md
category: reference
title: History of the telescope
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/History_of_the_telescope
date_saved: 2026-05-05T09:47:38.014297+00:00
instance: kb-cron
parent: history-of-the-telescope-20260505-0
summary:
In 1636 Marin Mersenne proposed a telescope consisting of a paraboloidal primary mirror and a paraboloidal secondary mirror bouncing the image through a hole in the primary, solving the problem of viewing the image. James Gregory went into further detail in his book Optica Promota (1663), pointing out that a reflecting telescope with a mirror that was shaped like the part of a conic section, would correct spherical aberration as well as the chromatic aberration seen in refractors. The design he came up with bears his name: the "Gregorian telescope"; but according to his own confession, Gregory had no practical skill and he could find no optician capable of realizing his ideas and after some fruitless attempts, was obliged to abandon all hope of bringing his telescope into practical use. In 1666 Isaac Newton, based on his theories of refraction and color, perceived that the faults of the refracting telescope were due more to a lens's varying refraction of light of different colors than to a lens's imperfect shape. He concluded that light could not be refracted through a lens without causing chromatic aberrations, although he incorrectly concluded from some rough experiments that all refracting substances would diverge the prismatic


id: history-of-the-telescope-20260505-4
file: data/en.wikipedia.org/wiki/History_of_the_telescope-4.md
category: reference
title: History of the telescope
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/History_of_the_telescope
date_saved: 2026-05-05T09:47:38.014297+00:00
instance: kb-cron
parent: history-of-the-telescope-20260505-0
summary:
About the year 1774 William Herschel (then a teacher of music in Bath, England) began to occupy his leisure hours with the construction of reflector telescope mirrors, finally devoted himself entirely to their construction and use in astronomical research. In 1778, he selected a 6+1⁄4-inch (16 cm) reflector mirror (the best of some 400 telescope mirrors which he had made) and with it, built a 7-foot (2.1 m) focal length telescope. Using this telescope, he made his early brilliant astronomical discoveries. In 1783, Herschel completed a reflector of approximately 18 inches (46 cm) in diameter and 20 ft (6.1 m) focal length. He observed the heavens with this telescope for some twenty years, replacing the mirror several times. In 1789 Herschel finished building his largest reflecting telescope with a mirror of 49 inches (120 cm) and a focal length of 40 ft (12 m), (commonly known as his 40-foot telescope) at his new home, at Observatory House in Slough, England. To cut down on the light loss from the poor reflectivity of the speculum mirrors of that day, Herschel eliminated the small diagonal mirror from his design and tilted his primary mirror so he could view the formed image directly.


id: history-of-the-telescope-20260505-5
file: data/en.wikipedia.org/wiki/History_of_the_telescope-5.md
category: reference
title: History of the telescope
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/History_of_the_telescope
date_saved: 2026-05-05T09:47:38.014297+00:00
instance: kb-cron
parent: history-of-the-telescope-20260505-0
summary:
From the time of the invention of the first refracting telescopes it was generally supposed that chromatic errors seen in lenses simply arose from errors in the spherical figure of their surfaces. Opticians tried to construct lenses of varying forms of curvature to correct these errors. Isaac Newton discovered in 1666 that chromatic colors actually arose from the un-even refraction of light as it passed through the glass medium. This led opticians to experiment with lenses constructed of more than one type of glass in an attempt to canceling the errors produced by each type of glass. It was hoped that this would create an "achromatic lens"; a lens that would focus all colors to a single point, and produce instruments of much shorter focal length. The first person who succeeded in making a practical achromatic refracting telescope was Chester Moore Hall from Essex, England. He argued that the different humours of the human eye refract rays of light to produce an image on the retina which is free from color, and he reasonably argued that it might be possible to produce a like result by combining lenses composed of different refracting media. After devoting some time to the inquiry


