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LORAN
LORAN, short for long range navigation, was a hyperbolic radio navigation system developed in the United States during World War II. It was similar to the UK's Gee system but operated at lower frequencies in order to provide an improved range up to with an accuracy of tens of miles. It was first used for ship convoys crossing the Atlantic Ocean, and then by long-range patrol aircraft, but found its main use on the ships and aircraft operating in the Pacific theater during World War II. LORAN, in its original form, was an expensive system to implement, requiring a cathode ray tube (CRT) display. This limited use to the military and large commercial users. Automated receivers became available in the 1950s, but the same improved electronics also opened the possibility of new systems with higher accuracy. The U.S. Navy began development of Loran-B, which offered accuracy on the order of a few tens of feet, but ran into significant technical problems. The U.S. Air Force worked on a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Loran-C
Loran-C is a hyperbolic radio navigation system that allows a receiver to determine its position by listening to low frequency radio signals that are transmitted by fixed land-based radio beacons. Loran-C combined two different techniques to provide a signal that was both long-range and highly accurate, features that had been incompatible. Its disadvantage was the expense of the equipment needed to interpret the signals, which meant that Loran-C was used primarily by militaries after it was introduced in 1957. By the 1970s, the cost, weight and size of electronics needed to implement Loran-C had been dramatically reduced because of the introduction of solid-state electronics and, from the mid-1970s, early microcontrollers to process the signal. Low-cost and easy-to-use Loran-C units became common from the late 1970s, especially in the early 1980s, and the earlier LORAN system was discontinued in favor of installing more Loran-C stations around the world. Loran-C became one of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
LORAN AN-APN-4 Receiver Set
LORAN, short for long range navigation, was a Hyperbolic navigation, hyperbolic radio navigation system developed in the United States during World War II. It was similar to the UK's Gee (navigation), Gee system but operated at lower frequencies in order to provide an improved range up to with an accuracy of tens of miles. It was first used for ship convoys crossing the Atlantic Ocean, and then by long-range patrol aircraft, but found its main use on the ships and aircraft operating in the Pacific theater during World War II. LORAN, in its original form, was an expensive system to implement, requiring a cathode ray tube (CRT) display. This limited use to the military and large commercial users. Automated receivers became available in the 1950s, but the same improved electronics also opened the possibility of new systems with higher accuracy. The U.S. Navy began development of Loran-B, which offered accuracy on the order of a few tens of feet, but ran into significant technical p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
LORAN R-65 APN-9
LORAN, short for long range navigation, was a hyperbolic radio navigation system developed in the United States during World War II. It was similar to the UK's Gee system but operated at lower frequencies in order to provide an improved range up to with an accuracy of tens of miles. It was first used for ship convoys crossing the Atlantic Ocean, and then by long-range patrol aircraft, but found its main use on the ships and aircraft operating in the Pacific theater during World War II. LORAN, in its original form, was an expensive system to implement, requiring a cathode ray tube (CRT) display. This limited use to the military and large commercial users. Automated receivers became available in the 1950s, but the same improved electronics also opened the possibility of new systems with higher accuracy. The U.S. Navy began development of Loran-B, which offered accuracy on the order of a few tens of feet, but ran into significant technical problems. The U.S. Air Force worked on a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
LORAN Display In Canso
LORAN, short for long range navigation, was a hyperbolic radio navigation system developed in the United States during World War II. It was similar to the UK's Gee system but operated at lower frequencies in order to provide an improved range up to with an accuracy of tens of miles. It was first used for ship convoys crossing the Atlantic Ocean, and then by long-range patrol aircraft, but found its main use on the ships and aircraft operating in the Pacific theater during World War II. LORAN, in its original form, was an expensive system to implement, requiring a cathode ray tube (CRT) display. This limited use to the military and large commercial users. Automated receivers became available in the 1950s, but the same improved electronics also opened the possibility of new systems with higher accuracy. The U.S. Navy began development of Loran-B, which offered accuracy on the order of a few tens of feet, but ran into significant technical problems. The U.S. Air Force worked on a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hyperbolic Navigation
Hyperbolic navigation is a class of radio navigation systems in which a navigation receiver instrument is used to determine location based on the difference in timing (phase) of radio waves received from radio navigation beacon transmitters. Such systems rely on the ability of two widely separated stations to broadcast a signal that is highly correlated in time. Typical systems either broadcast short pulses at the same time, or continual signals that are identical in phase. A receiver located at the midpoint between the two stations will receive the signals at the same time or have identical phase, but at any other location the signal from the closer station will be received first or have a different phase. Determining the location of a receiver requires that the two synchronized stations be tuned in at the same time so the signals can be compared. This reveals a ''difference'' in time, corresponding to a relative distance closer to one station or the other. Plotting all the loc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radio Navigation
Radio navigation or radionavigation is the application of radio frequencies to determine a position of an object on the Earth, either the vessel or an obstruction. Like radiolocation, it is a type of radiodetermination. The basic principles are measurements from/to electric beacons, especially * Angular directions, e.g. by bearing, radio phases or interferometry, * Distances, e.g. ranging by measurement of time of flight between one transmitter and multiple receivers or vice versa, * Distance ''differences'' by measurement of times of arrival of signals from one transmitter to multiple receivers or vice versa * Partly also velocity, e.g. by means of radio Doppler shift. Combinations of these measurement principles also are important—e.g., many radars measure range and azimuth of a target. Bearing-measurement systems These systems used some form of directional radio antenna to determine the location of a broadcast station on the ground. Conventional navigation techniques a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
160-meter Band
160-meter band refers to the band of radio frequencies between 1.8 and 2 MHz, just above the medium wave broadcast band. For many decades the lowest radio frequency band allocated for use by amateur radio, before the adoption, at the beginning of the 21st century in most countries, of the 630- and 2200-meter bands. Amateur operators often refer to 160 meters as the Top Band"Top band" possibly refers to the position of 2 MHz very nearly at the top of the medium frequency band (MF); it is the highest amateur band within MF. It is also sometimes nicknamed the "Gentleman's Band" in contrast to the often-freewheeling activity in the 80-, 40- and 20-meter bands. Frequency allocations The International Telecommunication Union currently allocates all frequencies from 1.81–2 MHz to amateur radio operations in ITU Region 1 (Europe, Greenland, Africa, the Middle East west of the Persian Gulf and including Iraq, the former Soviet Union and Mongolia) and 1.8 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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] |
Alfred Lee Loomis
Alfred Lee Loomis (November 4, 1887 – August 11, 1975) was an American attorney, investment banker, philanthropist, scientist, physicist, inventor of the LORAN Long Range Navigation System and a lifelong patron of scientific research. He established the Loomis Laboratory in Tuxedo Park, New York, and his role in the development of radar and the atomic bomb contributed to the Allied victory in World War II. He invented the Aberdeen Chronograph for measuring muzzle velocities, contributed significantly (perhaps critically, according to Luis Alvarez) to the development of a ground-controlled approach technology for aircraft, and participated in preliminary meetings of the Manhattan Project. Loomis also made contributions to biological instrumentation. Working with Edmund Newton Harvey he co-invented the microscope centrifuge, and pioneered techniques for electroencephalography. In 1937, he discovered the sleep K-complex brainwave. During the Great Depression, Loomis anonymousl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gee (navigation)
Gee, sometimes written GEE, was a radio navigation system used by the Royal Air Force during World War II. It measured the time delay between two radio signals to produce a fix, with accuracy on the order of a few hundred metres at ranges up to about . It was the first hyperbolic navigation system to be used operationally, entering service with RAF Bomber Command in 1942. Gee was devised by Robert Dippy as a short-range blind landing system to improve safety during night operations. During development by the Telecommunications Research Establishment (TRE) at Swanage, the range was found to be far better than expected. It then developed into a long-range, general navigation system. For large, fixed targets, such as the cities that were attacked at night, Gee offered enough accuracy to be used as an aiming reference without the need to use a bombsight or other external references. Jamming reduced its usefulness as a bombing aid, but it remained in use as a navigational aid in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Telecommunications Research Establishment
The Telecommunications Research Establishment (TRE) was the main United Kingdom research and development organization for radio navigation, radar, infra-red detection for heat seeking missiles, and related work for the Royal Air Force (RAF) during World War II and the years that followed. It was regarded as "the most brilliant and successful of the English wartime research establishments" under "Rowe, who saw more of the English scientific choices between 1935 and 1945 than any single man." The name was changed to Radar Research Establishment in 1953, and again to the Royal Radar Establishment in 1957. This article covers the precursor organizations and the Telecommunications Research Establishment up to the time of the name change. The later work at the site is described in the separate article about RRE. History TRE is best known for work on defensive and offensive radar. TRE also made substantial contributions to radio-navigation and to jamming enemy radio-navigation. Rad ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cathode Ray Tube
A cathode-ray tube (CRT) is a vacuum tube containing one or more electron guns, which emit electron beams that are manipulated to display images on a phosphorescent screen. The images may represent electrical waveforms ( oscilloscope), pictures (television set, computer monitor), radar targets, or other phenomena. A CRT on a television set is commonly called a picture tube. CRTs have also been used as memory devices, in which case the screen is not intended to be visible to an observer. The term ''cathode ray'' was used to describe electron beams when they were first discovered, before it was understood that what was emitted from the cathode was a beam of electrons. In CRT television sets and computer monitors, the entire front area of the tube is scanned repeatedly and systematically in a fixed pattern called a raster. In color devices, an image is produced by controlling the intensity of each of three electron beams, one for each additive primary color (red, green, and bl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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