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Altazimuth Mount
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 primar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Telescope Mount
A telescope mount is a mechanical structure which supports a telescope. Telescope mounts are designed to support the mass of the telescope and allow for accurate pointing of the instrument. Many sorts of mounts have been developed over the years, with the majority of effort being put into systems that can track the motion of the fixed stars as the Earth rotates. Fixed mounts Fixed telescope mounts are entirely fixed in one position, such as Zenith telescopes that point only straight up and the National Radio Astronomy Observatory's Green Bank fixed radio ' horn' built to observe Cassiopeia A. Fixed altitude mounts Fixed-altitude mounts usually have the primary optics fixed at an altitude angle while rotating horizontally (in azimuth). They can cover the whole sky but only observe objects for the short time when that object passes a specific altitude and azimuth. Transit mounts Transit mounts are single axis mounts fixed in azimuth while rotating in altitude, usually ori ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dobson Class
Dobson may refer to: People : ''For a listing of people with the surname "Dobson", see Dobson (surname).'' Places * Dobson High School in Arizona, US * Dobson, Mississippi, a ghost town in Rankin County, Mississippi, US * Dobson, North Carolina, US * Mount Dobson, New Zealand * Dobson, New Zealand Things * ''Dobson (Litigation Guardian of) v. Dobson'', [1999] 2 S.C.R. 753 (Supreme Court of Canada decision)) * Dobson Communications * Dobson ozone spectrophotometer * Dobson Pipe Organ Builders, a pipe organ manufacturer based in Iowa * Dobsonian telescope invented by amateur astronomer John Lowry Dobson * Dobson unit, a unit of measurement of atmospheric ozone named after British physicist Gordon M. B. Dobson {{disambig ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Newtonian Reflectors
The Newtonian telescope, also called the Newtonian reflector or just a Newtonian, is a type of reflecting telescope invented by the English scientist Sir Isaac Newton, using a concave primary mirror and a flat diagonal secondary mirror. Newton's first reflecting telescope was completed in 1668 and is the earliest known functional reflecting telescope. The Newtonian telescope's simple design has made it very popular with amateur telescope makers. Description 
A Newtonian telescope is composed of a
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John Dobson (astronomer)
John Lowry Dobson (14 September 1915 – 15 January 2014) was an American amateur astronomer and is best known for the Dobsonian telescope, a portable, low-cost Newtonian reflector telescope. He was also known for his efforts to promote awareness of astronomy (and his unorthodox views of physical cosmology) through public lectures including his performances of " sidewalk astronomy". Dobson was also the co-founder of the amateur astronomical group, the San Francisco Sidewalk Astronomers. Biography Dobson was born to Methodist missionary parents in China, but moved with his family back to the U.S. as a young child. He was a “belligerent atheist” as a young man. After earning a master's in chemistry, he encountered a teacher of a Vedanta monastic order, which seeks to integrate Veda-based religious precepts with rational inquiry, and joined the order, where he served as a Vedantan monk for 23 years. After leaving the order (in part because the time he surreptitiously ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dobsonian Telescope
A Dobsonian telescope is an altazimuth mount, altazimuth-mounted Newtonian telescope design popularized by John Dobson (amateur astronomer), John Dobson in 1965 and credited with vastly increasing the size of telescopes available to amateur astronomy, amateur astronomers. Dobson's telescopes featured a simplified mechanical design that was easy to manufacture from readily available components to create a large, portable, low-cost telescope. The design is optimized for observing faint deep-sky objects such as nebulae and galaxies. This type of observation requires a large Objective (optics), objective diameter (i.e. Optical telescope#Light-gathering power, light-gathering power) of relatively short focal length and portability for travel to less light pollution, light-polluted locations. Dobsonians are intended to be what is commonly called a "light bucket". Operating at low magnification, the design therefore omits features found in other amateur telescopes such as Equatorial moun ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Largest Optical Reflecting Telescopes
This list of the largest optical reflecting telescopes with Objective (optics), objective diameters of or greater is sorted by aperture, which is a measure of the light-gathering power and resolution of a reflecting telescope. The mirrors themselves can be larger than the aperture, and some telescopes may use aperture synthesis through interferometry. Telescopes designed to be used as optical astronomical interferometers such as the Keck I and II used together as the Keck Interferometer (up to 85 m) can reach higher resolutions, although at a narrower range of observations. When the two mirrors are on one mount, the combined mirror spacing of the Large Binocular Telescope (22.8 m) allows fuller use of the aperture synthesis. Largest does not always equate to being the best telescopes, and overall light gathering power of the optical system can be a poor measure of a telescope's performance. space observatory, Space-based telescopes, such as the Hubble Space Telescope, t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zenith
The zenith (, ) is the imaginary point on the celestial sphere directly "above" a particular location. "Above" means in the vertical direction (Vertical and horizontal, plumb line) opposite to the gravity direction at that location (nadir). The zenith is the "highest" point on the celestial sphere. The direction opposite of the zenith is the nadir. Origin The word ''zenith'' derives from an inaccurate reading of the Arabic language, Arabic expression (), meaning "direction of the head" or "path above the head", by Medieval Latin scribes in the Middle Ages (during the 14th century), possibly through Old Spanish. It was reduced to ''samt'' ("direction") and miswritten as ''senit''/''cenit'', the ''m'' being misread as ''ni''. Through the Old French ''cenith'', ''zenith'' first appeared in the 17th century. Relevance and use The term ''zenith'' sometimes means the culmination, highest point, way, or level reached by a celestial body on its daily apparent path around a given poi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gimbal Lock
Gimbal lock is the loss of one degree of freedom (mechanics), degree of freedom in a multi-dimensional mechanism at certain alignments of the axes. In a three-dimensional three-gimbal mechanism, gimbal lock occurs when the axes of two of the gimbals are driven into a parallel configuration, "locking" the system into rotation in a degenerate two-dimensional space. The term can be misleading in the sense that none of the individual gimbals is actually restrained. All three gimbals can still rotate freely about their respective axes of suspension. Nevertheless, because of the parallel orientation of two of the gimbals' axes, there is no gimbal available to accommodate rotation about one axis, leaving the suspended object effectively locked (i.e. unable to rotate) around that axis. The problem can be generalized to other contexts, where a coordinate system loses definition of one of its variables at certain values of the other variables. Gimbals A gimbal is a ring that is suspen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Setting Circles
Setting circles are used on telescopes equipped with an equatorial mount to find celestial objects by their equatorial coordinates, often used in star charts and ephemerides. Description Setting circles consist of two graduated disks attached to the axes – right ascension (RA) and declination (DEC) – of an equatorial mount. The RA disk is graduated into hours, minutes, and seconds. The DEC disk is graduated into degrees, arcminutes, and arcseconds. Since the RA coordinates are fixed onto the celestial sphere, the RA disk is usually driven by a clock mechanism in sync with sidereal time. Locating an object on the celestial sphere using setting circles is similar to finding a location on a terrestrial map using latitude and longitude. Sometimes the RA setting circle has two scales on it: one for the Northern Hemisphere and one for the Southern. Application Research telescopes Historically setting circles have rivaled the telescopes optics as far as difficulty in constructio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
