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Foster Scanner
{{Short description, Type of radar system The Foster scanner, or Variable Path scanner, is a type of radar system that produces a narrow beam that rapidly scans an area in front of it. Foster scanners were widely used in post-World War II radar systems used for artillery and mortar spotting. Modern radars in this role normally use electronic scanning in place of a Foster scanner for this purpose. Description The Foster scanner consists of two parts; a box-shaped antenna and the "scanner" itself. These are normally placed in front of a shaped reflector. The antenna consists of a thin rectangular section of a parabolic antenna, as if one cut the sides away from a conventional parabolic antenna, leaving only the thin strip where the feed horn is mounted. Rectangular plates are placed on either side of the "cut", extending forward in the direction of broadcast. The resulting system has the basic size and shape of a large pizza box with the rear side rounded. In the UK, these are kno ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
AN MPQ-4A
An, AN, aN, or an may refer to: Businesses and organizations * Airlinair (IATA airline code AN) * Alleanza Nazionale, a former political party in Italy * AnimeNEXT, an annual anime convention located in New Jersey * Anime North, a Canadian anime convention * Ansett Australia, a major Australian airline group that is now defunct (IATA designator AN) * Apalachicola Northern Railroad (reporting mark AN) 1903–2002 ** AN Railway, a successor company, 2002– * Aryan Nations, a white supremacist religious organization * Australian National Railways Commission, an Australian rail operator from 1975 until 1987 * Antonov, a Ukrainian (formerly Soviet) aircraft manufacturing and services company, as a model prefix Entertainment and media * Antv, an Indonesian television network * '' Astronomische Nachrichten'', or ''Astronomical Notes'', an international astronomy journal * ''Avisa Nordland'', a Norwegian newspaper * ''Sweet Bean'' (あん), a 2015 Japanese film also known as ''An ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
AN/MPQ-4
The Radar Set AN/MPQ-4 was a US Army counter-battery radar primarily used to find the location of enemy mortars and larger artillery in a secondary role. Built by General Electric, it first entered service in 1958, replacing the earlier and much simpler AN/MPQ-10. The MPQ-4 could determine the location of an enemy mortar in as little as 20 seconds by observing a single round, whereas the MPQ-10 required several rounds to be launched and could take 4 to 5 minutes to take a "fix". The MPQ-4 remained one of the primary US counter-battery systems through the late 1970s until it was replaced by passive electronically scanned array radars like the AN/TPQ-36. History During World War II, operators or the newly introduced SCR-584 radar noticed they sometimes could see artillery shells in flight. With considerable effort, they could follow these rounds and then manually estimate the radial trajectory. By looking along that path, they could see the rounds being launched and then forward t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
National Research Council (Canada)
The National Research Council Canada (NRC; french: Conseil national de recherches Canada) is the primary national agency of the Government of Canada dedicated to science and technology research and development, research & development. It is the largest federal research & development organization in Canada. The Minister of Innovation, Science and Industry, Minister of Innovation, Science, and Economic Development (currently, François-Philippe Champagne) is responsible for the NRC. Mandate NRC is an Government agency, agency of the Government of Canada, and its mandate is set out in the ''National Research Council Act''. Under the Act, the NRC is responsible for: * Undertaking, assisting or promoting scientific and industrial research in fields of importance to Canada; * Providing vital scientific and technological services to the research and industrial communities; * Investigating standards and methods of measurement; * Working on the standardization and certification of sc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
MIT Radiation Laboratory
The Radiation Laboratory, commonly called the Rad Lab, was a microwave and radar research laboratory located at the Massachusetts Institute of Technology (MIT) in Cambridge, Massachusetts. It was first created in October 1940 and operated until 31 December 1945 when its functions were dispersed to industry, other departments within MIT, and in 1951, the newly formed MIT Lincoln Laboratory. The use of microwaves for various radio and radar uses was highly desired before the war, but existing microwave devices like the klystron were far too low powered to be useful. Alfred Lee Loomis, a millionaire and physicist who headed his own private laboratory, organized the Microwave Committee to consider these devices and look for improvements. In early 1940, Winston Churchill organized what became the Tizard Mission to introduce U.S. researchers to several new technologies the UK had been developing. Among these was the cavity magnetron, a leap forward in the creation of microwaves that made ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
John Stuart Foster
John Stuart Foster (May 30, 1890 – September 9, 1964) was a Canadian physicist. Biography Born in Clarence, Nova Scotia, he completed his Ph.D. at Yale University with a dissertation on the first measurements of the Stark effect in Helium. In 1924 he gained an appointment as assistant professor at McGill University in Montreal, where he taught physics. He became associate professor in 1930. During World War II he served as a liaison officer for the National Research Council, working at the MIT-run Radiation Laboratory on radar research and development. He developed a fast-scan radar antenna that became known as the "Foster scanner". He returned to McGill in 1944, where he directed the construction of a 100-MeV cyclotron. This instrument was commissioned in 1949. At the time this was the second largest in the world. From 1952 until 1954 he was chairman of the physics department at McGill. He died in Berkeley, California. Legacy The ''John Stuart Foster Radiation Laborator ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Green Archer (radar)
Green Archer, also called Radar, Field Artillery, No 8 was a widely used British mortar locating radar operating in the X band using a Foster scanner. Developed by EMI after an experimental model by the Royal Radar Establishment, it was in British service from 1962 until 1975 with the Royal Artillery. A self-propelled version was designated FV436 or Radar, FA, No 8 Mk 2. It was replaced by Cymbeline starting in 1975. Concept Mortars, using indirect fire, became a major threat to infantry in World War II. It was found that mortar bombs in flight could be detected and tracked by radar. US and UK anti-aircraft radars were used and specialised mortar locating radars appeared at the end of the war, and were used in Korea with varying degrees of success. Hostile mortars had to be accurately located before they could be attacked with indirect fire from guns or mortars. Since hostile mortars moved frequently to avoid return fire it was essential to have a means of locating them to a f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ballistic Calculator
A ballistic table or ballistic chart is a tool which predicts the trajectory of a projectile, and is used to compensate for physical effects in order to increase the probability of the projectile reaching the intended target. Ballistic tables are used in hunting, sport shooting, military and scientific applications. Corrections in ballistic tables are given relative to a zero range. Ballistic charts are often given in angular measurements, with units in either milliradians (mil) or minutes of arc (moa). The tables are usually generated using specifically designed computer programs built on mathematical functions, known as ballistic calculators. The number of inputs to the ballistic calculator can sometimes vary depended on the specific generator, or the user may choose to only input certain variables. For example, a very simple drop table can be made using inputs for the sight adjustment value (in mil or moa), the zero range, intended target ranges, muzzle velocity, caliber, ba ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
B-scope
A radar display is an electronic device to present radar data to the operator. The radar system transmits pulses or continuous waves of electromagnetic radiation, a small portion of which backscatter off targets (intended or otherwise) and return to the radar system. The receiver converts all received electromagnetic radiation into a continuous electronic analog signal of varying (or oscillating) voltage that can be converted then to a screen display. Modern systems typically use some sort of raster scan display to produce a map-like image. Early in radar development, however, numerous circumstances made such displays difficult to produce. People ultimately developed several different display types. Oscilloscopes Early radar displays used adapted oscilloscopes with various inputs. An oscilloscope generally receives three ''channels'' of varying (or oscillating) voltage as input and displays this information on a cathode ray tube. The oscilloscope amplifies the input voltages a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lobe Switching
Lobe switching is a method used on early radar sets to improve tracking accuracy. It uses two slightly separated antenna elements to send the beam slightly to either side of the midline of the antenna. The radar signal switched between the two and produced two "blips" on the display. By comparing the lengths of the blips, the operator could find which one gave the stronger return, thereby indicating which direction the antenna should be moved to point directly at the target. The concept was used only briefly, and was almost completely replaced by conical scanning systems by the end of World War II. The concept is also infrequently referred to as sequential lobing, particularly when the signal steps between several different angles rather than just two. Description Early radar antennas generally consisted of a number of small dipole antennas in front of a passive reflector. The dipoles were placed in order to have them constructively interfere in front of the antenna, thereby "aimi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Counterbattery Radar
A counter-battery radar (alternatively weapon tracking radar or COBRA) is a radar system that detects artillery projectiles fired by one or more guns, howitzers, mortars or rocket launchers and, from their trajectories, locates the position on the ground of the weapon that fired it. Such radars are a subclass of the wider class of target acquisition radars. Early counter-battery radars were generally used against mortars, whose lofted trajectories were highly symmetrical and allowed easy calculation of the launcher's location. Starting in the 1970s, digital computers with improved calculation capabilities allowed more complex trajectories of long-range artillery to also be determined. Normally, these radars would be attached to friendly artillery units or their support units, allowing them to quickly arrange counter-battery fire. With the aid of modern communications systems, the information from a single radar can be rapidly disseminated over long distances. This allows the r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radar
Radar is a detection system that uses radio waves to determine the distance (''ranging''), angle, and radial velocity of objects relative to the site. It can be used to detect aircraft, ships, spacecraft, guided missiles, motor vehicles, weather formations, and terrain. A radar system consists of a transmitter producing electromagnetic waves in the radio or microwaves domain, a transmitting antenna, a receiving antenna (often the same antenna is used for transmitting and receiving) and a receiver and processor to determine properties of the objects. Radio waves (pulsed or continuous) from the transmitter reflect off the objects and return to the receiver, giving information about the objects' locations and speeds. Radar was developed secretly for military use by several countries in the period before and during World War II. A key development was the cavity magnetron in the United Kingdom, which allowed the creation of relatively small systems with sub-meter resolution. Th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
World War II
World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the vast majority of the world's countries—including all of the great powers—forming two opposing military alliances: the Allies and the Axis powers. World War II was a total war that directly involved more than 100 million personnel from more than 30 countries. The major participants in the war threw their entire economic, industrial, and scientific capabilities behind the war effort, blurring the distinction between civilian and military resources. Aircraft played a major role in the conflict, enabling the strategic bombing of population centres and deploying the only two nuclear weapons ever used in war. World War II was by far the deadliest conflict in human history; it resulted in 70 to 85 million fatalities, mostly among civilians. Tens of millions died due to genocides (including the Holocaust), starvation, ma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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