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Erstling IFF Transceiver
FuG 25a ''Erstling'' (German: ''"Firstborn"'', ''"Debut"'', sometimes FuGe) was an identification friend or foe (IFF) transponder installed in ''Luftwaffe'' aircraft starting in 1941 in order to allow German Freya radar stations to identify them as friendly. The system was also used as a navigation transponder as part of the EGON night bombing system during 1943 and 1944. It was the second IFF system to be used, replacing the FuG 25 ''Zwilling''. The basic concept of IFF had been introduced in November 1938 but little work was carried out on it initially. In 1939 the Würzburg radar was chosen to replace an earlier fire control radar from Lorenz. This led to the FuG 25 ''Zwilling'' which responded to the Würzburg signals. Meanwhile, the GEMA company introduced the long-range Freya radar and a more advanced IFF system to work with it. This Erstling unit was clearly superior to the Zwilling, but 10,000 Zwilling units had been produced and they were slow to abandon it. Starting i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Germany
Germany,, officially the Federal Republic of Germany, is a country in Central Europe. It is the second most populous country in Europe after Russia, and the most populous member state of the European Union. Germany is situated between the Baltic and North seas to the north, and the Alps to the south; it covers an area of , with a population of almost 84 million within its 16 constituent states. Germany borders Denmark to the north, Poland and the Czech Republic to the east, Austria and Switzerland to the south, and France, Luxembourg, Belgium, and the Netherlands to the west. The nation's capital and most populous city is Berlin and its financial centre is Frankfurt; the largest urban area is the Ruhr. Various Germanic tribes have inhabited the northern parts of modern Germany since classical antiquity. A region named Germania was documented before AD 100. In 962, the Kingdom of Germany formed the bulk of the Holy Roman Empire. During the 16th ce ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Friendly Fire
In military terminology, friendly fire or fratricide is an attack by belligerent or neutral forces on friendly troops while attempting to attack enemy/hostile targets. Examples include misidentifying the target as hostile, cross-fire while engaging an enemy, long range ranging errors or inaccuracy. Accidental fire not intended to attack enemy/hostile targets, and deliberate firing on one's own troops for disciplinary reasons, is not called friendly fire,Regan, Geoffrey (2002) ''Backfire: a history of friendly fire from ancient warfare to the present day'', Robson Books and neither is unintentional harm to civilian or neutral targets, which is sometimes referred to as collateral damage. Training accidents and bloodless incidents also do not qualify as friendly fire in terms of casualty reporting. Use of the term "friendly" in a military context for allied personnel started during the First World War, often when shells fell short of the targeted enemy. The term ''friendly fire'' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plan Position Indicator
A plan position indicator (PPI) is a type of radar display that represents the radar antenna in the center of the display, with the distance from it and height above ground drawn as concentric circles. As the radar antenna rotates, a radial trace on the PPI sweeps in unison with it about the center point. It is the most common type of radar display. Description The radar antenna sends pulses while rotating 360 degrees around the radar site at a fixed elevation angle. It can then change angle or repeat at the same angle according to the need. Return echoes from targets are received by the antenna and processed by the receiver and the most direct display of those data is the PPI. The height of the echoes increases with the distance to the radar, as represented in the adjacent image. This change is not a straight line but a curve as the surface of the Earth is curved and ''sinks'' below the radar horizon. For fixed-site installations, north is usually represented at the top of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ground Controlled Interception
Ground-controlled interception (GCI) is an air defence tactic whereby one or more radar stations or other observational stations are linked to a command communications centre which guides interceptor aircraft to an airborne target. This tactic was pioneered during World War I by the London Air Defence Area organization, which became the Royal Air Force's Dowding system in World War II, the first national-scale system. The ''Luftwaffe'' introduced similar systems during the war, but most other combatants did not suffer the same threat of air attack and did not develop complex systems like these until the Cold War era. Today the term GCI refers to the style of battle direction, but during WWII it also referred to the radars themselves. Specifically, the term was used to describe a new generation of radars that spun on their vertical axis in order to provide a complete 360 degree view of the sky around the station. Previous systems, notably Chain Home (CH), could only be directed alon ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Battle Of The Beams
The Battle of the Beams was a period early in the Second World War when bombers of the German Air Force (''Luftwaffe'') used a number of increasingly accurate systems of radio navigation for night bombing in the United Kingdom. British scientific intelligence at the Air Ministry fought back with a variety of their own increasingly effective means, involving jamming and deception signals. The period ended when the Wehrmacht moved their forces to the East in May 1941, in preparation for the attack on the Soviet Union. The idea of "beam" based navigation was developed during the 1930s, initially as a blind landing aid. The basic concept is to produce two directional radio signals that are aimed slightly to the left and right of a runway's midline. Radio operators in the aircraft listen for these signals and determine which of the two beams they are flying in. This is normally accomplished by sending Morse code signals into the two beams, to identify right and left. For bombing, the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pathfinder (military)
In military organizations, a pathfinder is a specialized soldier inserted or dropped into place in order to set up and operate drop zones, pickup zones, and helicopter landing sites for airborne operations, air resupply operations, or other air operations in support of the ground unit commander. Pathfinders first appeared in World War II, where they served with distinction, and continue to serve an important role in today's modern armed forces, providing commanders with the option of flexibly employing air assets. History United Kingdom During the Second World War small groups of parachute soldiers were formed into pathfinder units, to parachute ahead of the main force. Their tasks were to mark the drop zones (DZ) or landing zones (LZ), set up radio beacons as a guide for the aircraft carrying the main force and to clear and protect the area as the main force arrived. The units were formed into two companies to work with the two British airborne divisions created during th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rennie Whitehead
Rennie is a given name, nickname and surname. People with the surname * Alistair Rennie, Scottish author * Allan Rennie (born 1960), Scottish footballer * Andy Rennie (Scottish footballer) (1901–1938), footballer with Luton Town * Andy Rennie (New Zealand footballer), New Zealand footballer * Bob Rennie (born 1956), Canadian real estate marketer and art collector * Bryan Rennie (historian) (born 1954), British historian of religions * Bryan Rennie (rugby union) (born 1984), South African rugby union player * Callum Keith Rennie (born 1960), Canadian actor * Connor Rennie (born 1991), Scottish footballer * David Rennie (film editor), American film editor * David Rennie (footballer) (born 1964), Scottish footballer * Edward Rennie (1852–1927), Australian scientist * Eliza Rennie (ca. 1813–unknown) Scottish romantic/Gothic short story author * Frank Rennie (1918–1992), New Zealand soldier * Gavin Rennie (born 1976), Zimbabwean cricketer * Gaye Rennie ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neon Lamp
A neon lamp (also neon glow lamp) is a miniature gas discharge lamp. The lamp typically consists of a small glass capsule that contains a mixture of neon and Penning mixture, other gases at a low pressure and two electrodes (an anode and a cold cathode, cathode). When sufficient voltage is applied and sufficient current is supplied between the electrodes, the lamp produces an orange glow discharge. The glowing portion in the lamp is a thin region near the cathode; the larger and much longer neon signs are also glow discharges, but they use the Glow_discharge#Positive_column, positive column which is not present in the ordinary neon lamp. Neon glow lamps were widely used as indicator lamps in the displays of electronic instruments and appliances. They are still sometimes used for their electrical simplicity in high-voltage circuits. History Neon was discovered in 1898 by William Ramsay and Morris W. Travers. The characteristic, brilliant red color that is emitted by gaseous neon ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Intermediate Frequency
In communications and electronic engineering, an intermediate frequency (IF) is a frequency to which a carrier wave is shifted as an intermediate step in transmission or reception. The intermediate frequency is created by mixing the carrier signal with a local oscillator signal in a process called heterodyning, resulting in a signal at the difference or beat frequency. Intermediate frequencies are used in superheterodyne radio receivers, in which an incoming signal is shifted to an IF for amplification before final detection is done. Conversion to an intermediate frequency is useful for several reasons. When several stages of filters are used, they can all be set to a fixed frequency, which makes them easier to build and to tune. Lower frequency transistors generally have higher gains so fewer stages are required. It's easier to make sharply selective filters at lower fixed frequencies. There may be several such stages of intermediate frequency in a superheterodyne receiver; t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pulse Repetition Frequency
The pulse repetition frequency (PRF) is the number of pulses of a repeating signal in a specific time unit. The term is used within a number of technical disciplines, notably radar. In radar, a radio signal of a particular carrier frequency is turned on and off; the term "frequency" refers to the carrier, while the PRF refers to the number of switches. Both are measured in terms of cycle per second, or hertz. The PRF is normally much lower than the frequency. For instance, a typical World War II radar like the Type 7 GCI radar had a basic carrier frequency of 209 MHz (209 million cycles per second) and a PRF of 300 or 500 pulses per second. A related measure is the pulse width, the amount of time the transmitter is turned on during each pulse. After producing a brief pulse of radio signal, the transmitter is turned off in order for the receiver units to hear the reflections of that signal off distant targets. Since the radio signal has to travel out to the target and back ag ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Capacitor
A capacitor is a device that stores electrical energy in an electric field by virtue of accumulating electric charges on two close surfaces insulated from each other. It is a passive electronic component with two terminals. The effect of a capacitor is known as capacitance. While some capacitance exists between any two electrical conductors in proximity in a circuit, a capacitor is a component designed to add capacitance to a circuit. The capacitor was originally known as the condenser, a term still encountered in a few compound names, such as the ''condenser microphone''. The physical form and construction of practical capacitors vary widely and many types of capacitor are in common use. Most capacitors contain at least two electrical conductors often in the form of metallic plates or surfaces separated by a dielectric medium. A conductor may be a foil, thin film, sintered bead of metal, or an electrolyte. The nonconducting dielectric acts to increase the capacitor's c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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