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Mersenne-Schmidt
A three-mirror anastigmat is an anastigmat telescope built with three curved mirrors, enabling it to minimize all three main optical aberrations – spherical aberration, coma (optics), coma, and Astigmatism (optical systems), astigmatism. This is primarily used to enable wide fields of view, much larger than possible with telescopes with just one or two curved surfaces. A telescope with only one curved mirror, such as a Newtonian telescope, will always have aberrations. If the mirror is spherical, it will suffer from spherical aberration. If the mirror is made parabolic, to correct the spherical aberration, then it must necessarily suffer from coma and off-axis astigmatism. With two curved mirrors, such as the Ritchey–Chrétien telescope, coma can be minimized as well. This allows a larger useful field of view, and the remaining astigmatism is symmetrical around the distorted objects, allowing astrometry across the wide field of view. However, the astigmatism can be reduced by ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Applied Optics
''Applied Optics'' is a peer-reviewed scientific journal published by Optica three times a month. It was established in 1962 with John N. Howard as founding editor-in-chief and Patricia Wakeling as managing editor. Wakeling worked on the journal for over three decades. The editor-in-chief is Gisele Bennett. The journal covers all aspects of optics, photonics, imaging, and sensing. According to the ''Journal Citation Reports'', the journal has a 2023 impact factor The impact factor (IF) or journal impact factor (JIF) of an academic journal is a type of journal ranking. Journals with higher impact factor values are considered more prestigious or important within their field. The Impact Factor of a journa ... of 1.7. References External links * Optics journals Optica (society) academic journals English-language journals Academic journals established in 1962 Journals published between 27 and 51 times per year {{optics-journal-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NASA
The National Aeronautics and Space Administration (NASA ) is an independent agencies of the United States government, independent agency of the federal government of the United States, US federal government responsible for the United States's civil list of government space agencies, space program, aeronautics research and outer space, space research. National Aeronautics and Space Act, Established in 1958, it succeeded the National Advisory Committee for Aeronautics (NACA) to give the American space development effort a distinct civilian orientation, emphasizing peaceful applications in space science. It has since led most of America's space exploration programs, including Project Mercury, Project Gemini, the 1968–1972 Apollo program missions, the Skylab space station, and the Space Shuttle. Currently, NASA supports the International Space Station (ISS) along with the Commercial Crew Program and oversees the development of the Orion (spacecraft), Orion spacecraft and the Sp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Future Imagery Architecture
Future Imagery Architecture (FIA) was a program awarded to Boeing to design a new generation of optical and radar imaging US reconnaissance satellites for the National Reconnaissance Office (NRO). In 2005 NRO director Donald Kerr recommended the project's termination, and the optical component of the program was finally cancelled in September 2005 by Director of National Intelligence John Negroponte. FIA has been called by ''The New York Times'' "perhaps the most spectacular and expensive failure in the 50-year history of American spy satellite projects." Despite the optical component's cancellation, the radar component, known as Topaz, has continued, with four satellites in orbit . History Contractors In May 1999 Raytheon was awarded the contract for the deployment and integration of the ground infrastructure portion of FIA, the Mission Integration and Development (MIND) Program. In September 1999 the contract for the development, launch integration, and operations of FIA w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
KH-11 Kennen
The KH-11 KENNEN (later renamed CRYSTAL,p.199-200 then Evolved Enhanced CRYSTAL System, and codenamed 1010 and Key Hole) is a type of reconnaissance satellite first launched by the American National Reconnaissance Office (NRO) in December 1976. Manufactured by Lockheed Corporation, Lockheed in Sunnyvale, California, the KH-11 was the first American spy satellite to use Optoelectronics, electro-optical digital imaging, and to offer real-time optical observations. Later KH-11 satellites have been referred to by outside observers as KH-11B or KH-12, and by the names "Advanced KENNEN", "Improved Crystal" and "Ikon". Official budget documents refer to the latest generation of electro-optical satellites as ''Evolved Enhanced CRYSTAL System''. The Key Hole series was officially discontinued in favor of a random numbering scheme after repeated public references to KH-7 Gambit, KH-7 GAMBIT, KH-8 Gambit 3, KH-8 GAMBIT 3, KH-9 Hexagon, KH-9 HEXAGON, and KH-11 KENNEN satellites. The ca ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vera C
Vera may refer to: Names *Vera (surname), a surname (including a list of people with the name) *Vera (given name), a given name (including a list of people and fictional characters with the name) **Vera (), archbishop of the archdiocese of Tarragona Places Spain *Vera, AlmerĂa, a municipality in the province of AlmerĂa, Andalusia * Vera de Bidasoa, a municipality in the autonomous community of Navarra *La Vera, a comarca in the province of Cáceres, Extremadura United States * Vera, Illinois, an unincorporated community * Vera, Kansas, a ghost town * Vera, Missouri, an unincorporated community * Vera, Oklahoma, a town * Vera, Texas, an unincorporated community * Vera, Virginia, an unincorporated community * Veradale, Washington, originally known as Vera, CDP Elsewhere * Vera, Santa Fe, a city in the province of Santa Fe, Argentina * Vera Department, an administrative subdivision (departamento) of the province of Santa Fe * Vera, Mato Grosso, Brazil, a municipality * Cape Ve ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Euclid (spacecraft)
''Euclid'' is a wide-angle space telescope with a 600-megapixel camera to record visible light, a near-infrared spectrometer, and photometer, to determine the redshift of detected galaxies. It was developed by the European Space Agency (ESA) and the Euclid Consortium and was launched on 1 July 2023 from Cape Canaveral in Florida. The mission is named after the ancient Greek mathematician Euclid. After approximately one month, it reached its destination, a halo orbit around the Sun-Earth second Lagrange point L2, at an average distance of 1.5million kilometres beyond Earth's orbit. There the telescope is to remain operational for at least six years. The objective of the ''Euclid'' mission is to better understand dark energy and dark matter by accurately measuring the accelerating expansion of the universe. The Korsch-type telescope will measure the shapes of galaxies at varying distances from Earth and investigate the relationship between distance and redshift. ''Euclid'' i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
James Webb Space Telescope
The James Webb Space Telescope (JWST) is a space telescope designed to conduct infrared astronomy. As the largest telescope in space, it is equipped with high-resolution and high-sensitivity instruments, allowing it to view objects too old, List of the most distant astronomical objects, distant, or faint for the Hubble Space Telescope. This enables investigations across many fields of astronomy and cosmology, such as observation of the Population III star, first stars and the Galaxy formation and evolution, formation of the first galaxies, and detailed atmospheric characterization of potentially habitable exoplanets. Although the Webb's mirror diameter is 2.7 times larger than that of the Hubble Space Telescope, it produces images of comparable optical resolution, resolution because it observes in the longer-wavelength infrared spectrum. The longer the wavelength of the spectrum, the larger the information-gathering surface required (mirrors in the infrared spectrum or antenna a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vignetting
In photography and optics, vignetting ( ) is a reduction of an image's brightness or saturation toward the periphery compared to the image center. The word '' vignette'', from the same root as ''vine'', originally referred to a decorative border in a book. Later, the word came to be used for a photographic portrait that is clear at the center and fades off toward the edges. A similar effect is visible in photographs of projected images or videos off a projection screen, resulting in a so-called "hotspot" effect. Vignetting is often an unintended and undesired effect caused by camera settings or lens limitations. However, it is sometimes deliberately introduced for creative effect, such as to draw attention to the center of the frame. A photographer may deliberately choose a lens that is known to produce vignetting to obtain the effect, or it may be introduced with the use of special filters or post-processing procedures. When using zoom lenses, vignetting may occur ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Total Internal Reflection
In physics, total internal reflection (TIR) is the phenomenon in which waves arriving at the interface (boundary) from one medium to another (e.g., from water to air) are not refracted into the second ("external") medium, but completely reflected back into the first ("internal") medium. It occurs when the second medium has a higher wave speed (i.e., lower refractive index) than the first, and the waves are incident at a sufficiently oblique angle on the interface. For example, the water-to-air surface in a typical fish tank, when viewed obliquely from below, reflects the underwater scene like a mirror with no loss of brightness (Fig.1). TIR occurs not only with electromagnetic waves such as light and microwaves, but also with other types of waves, including sound and water waves. If the waves are capable of forming a narrow beam (Fig.2), the reflection tends to be described in terms of " rays" rather than waves; in a medium whose properties are independent of direction, such ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eisenberg Solid Three Mirror Anastigmat
Eisenberg is a German name in geography and a surname. Literally translated it means ″iron mountain″. ''Eisenberg'' may refer to: Mountains * Eisenberg (Knüll), a mountain in Hesse * Eisenberg (Korbach), a mountain in Hesse * Eisenberg (Ore Mountains), a mountain in Saxony Populated places In Germany *Eisenberg, Thuringia, a town in the Saale-Holzland district, Thuringia *Eisenberg, Rhineland-Palatinate, a town in the Donnersbergkreis, Rhineland-Palatinate * Eisenberg (Verbandsgemeinde), a collective municipality in the Donnersbergkreis, Rhineland-Palatinate *Eisenberg, Bavaria, a municipality in the district of Ostallgäu in Bavaria * Eisenberg Castle, Korbach, Hesse, former seat of the House of Waldeck In Austria *Eisenberg an der Raab, a town in Burgenland. *Deutsch Schützen-Eisenberg, a municipality in Burgenland. in Poland * Eisenberg, Kreis Sprottau/Schlesien, today Rudawica * Eisenberg, Kreis Heiligenbeil/Ostpreußen, today Żelazna Góra * Eisenberg, Kreis Str ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
