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Pip-squeak
Pip-squeak was a radio navigation system used by the British Royal Air Force during the early part of World War II. Pip-squeak used an aircraft's voice radio set to periodically send out a 1 kHz tone which was picked up by ground-based high-frequency direction finding (HFDF, "huff-duff") receivers. Using three HFDF measurements, observers could determine the location of friendly aircraft using triangulation. Pip-squeak was used by fighter aircraft during the Battle of Britain as part of the Dowding system, where it provided the primary means of locating friendly forces, and indirectly providing identification friend or foe (IFF). At the time, radar systems were sited on the shore and did not provide coverage over the inland areas, so IFF systems that produced unique radar images were not always useful for directing interceptions. Pip-squeak was added to provide coverage in these areas. As more radar stations were added and over-land areas became widely covered, pip-squeak was ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Identification Friend Or Foe
Identification, friend or foe (IFF) is an identification system designed for command and control. It uses a transponder that listens for an ''interrogation'' signal and then sends a ''response'' that identifies the broadcaster. IFF systems usually use radar frequencies, but other electromagnetic frequencies, radio or infrared, may be used. It enables military and civilian air traffic control interrogation systems to identify aircraft, vehicles or forces as friendly and to determine their bearing and range from the interrogator. IFF is used by both military and civilian aircraft. IFF was first developed during World War II, with the arrival of radar, and several friendly fire incidents. IFF can only positively identify friendly aircraft or other forces. If an IFF interrogation receives no reply or an invalid reply, the object is not positively identified as foe; friendly forces may not properly reply to IFF for various reasons such as equipment malfunction, and parties in the area ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
High-frequency Direction Finding
High-frequency direction finding, usually known by its abbreviation HF/DF or nickname huff-duff, is a type of radio direction finder (RDF) introduced in World War II. High frequency (HF) refers to a radio band that can effectively communicate over long distances; for example, between U-boats and their land-based headquarters. HF/DF was primarily used to catch enemy radios while they transmitted, although it was also used to locate friendly aircraft as a navigation aid. The basic technique remains in use to this day as one of the fundamental disciplines of signals intelligence, although typically incorporated into a larger suite of radio systems and radars instead of being a stand-alone system. Earlier systems used a mechanically rotated antenna or solenoid and an operator listening for peaks or nulls in the signal, which often took considerable time to determine the bearing on the order of a minute or more. Later systems used a set of antennas to receive the same signal in slightly ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
IFF Mark II
IFF Mark II was the first operational identification friend or foe system. It was developed by the Royal Air Force just before the start of World War II. After a short run of prototype Mark Is, used experimentally in 1939, the Mark II began widespread deployment at the end of the Battle of Britain in late 1940. It remained in use until 1943, when it began to be replaced by the standardised IFF Mark III, which was used by all Allied aircraft until long after the war ended. The Mark I was a simple system that amplified the signals of the British Chain Home radar systems, causing the aircraft's "blip" to extend on the radar display, identifying the aircraft as friendly. MarkI had the problem that the Gain (electronics), gain had to be adjusted in flight to keep it working; in the field, it was correct only half the time. Another problem was that it was sensitive to only one frequency and had to be manually tuned to different radar stations. In 1939, Chain Home was the only radar o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pip, Squeak And Wilfred
''Pip, Squeak and Wilfred'' was a British strip cartoon published in the ''Daily Mirror'' from 1919 to 1956 (with a break c. 1940–1950), as well as the '' Sunday Pictorial'' in the early years. It was conceived by Bertram Lamb, who took the role of Uncle Dick, signing himself (B.J.L.) in an early book, and was drawn until c. 1939 by Austin Bowen Payne, who always signed as A. B. Payne. It concerned the adventures of an orphaned family of animals. Pip, who assumed the "father" role, was a dog, while the "mother", Squeak, was a penguin. Wilfred was the "young son" and was a rabbit with very long ears. Character beginnings The characters Pip, Squeak and Wilfred were created by Bertram Lamb, a journalist on the ''Daily Mirror'', who was born in Islington, London, on 14 May 1887 and died in Switzerland in 1938. He never drew the cartoons, but thought up the idea of the characters. The origins of the characters are mentioned in the cartoon strips. Squeak was found in the London Zo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
RAF Biggin Hill
London Biggin Hill Airport is an operational general aviation airport at Biggin Hill in the London Borough of Bromley, located south-southeast of Central London. The airport was formerly a Royal Air Force station RAF Biggin Hill, and a small enclave on the airport still retains that designation. Biggin Hill is best known for its role during the Battle of Britain in the Second World War, when it served as one of the principal fighter bases protecting London and South East England from attack by German Luftwaffe bombers. Over the course of the war, fighters based at Biggin Hill claimed 1,400 enemy aircraft, at the cost of the lives of 453 Biggin Hill based aircrew. The airport has a CAA Ordinary Licence (Number P804) that allows flights for the public transport of passengers or for flying instruction as authorised by the licensee (Regional Airports Limited). It specialises in general aviation, handling a spectrum of traffic from private aviation to large business jets. It c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
RAF Fighter Command
RAF Fighter Command was one of the commands of the Royal Air Force. It was formed in 1936 to allow more specialised control of fighter aircraft. It served throughout the Second World War. It earned near-immortal fame during the Battle of Britain in 1940, when the Few held off the Luftwaffe attack on Britain. The Command continued until 17 November 1943, when it was disbanded and the RAF fighter force was split into two categories; defence and attack. The defensive force became Air Defence of Great Britain (ADGB) and the offensive force became the RAF Second Tactical Air Force. Air Defence of Great Britain was renamed back to Fighter Command in October 1944 and continued to provide defensive patrols around Great Britain. It was disbanded for the second time in 1968, when it was subsumed into the new Strike Command. Origins On 20 May 1926, the forerunner of Fighter Command was established as a group within Inland Area. On 1 June 1926, Fighting Area was transferred to the Air D ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hugh Dowding
Air Chief Marshal Hugh Caswall Tremenheere Dowding, 1st Baron Dowding, (24 April 1882 – 15 February 1970) was an officer in the Royal Air Force. He was Air Officer Commanding RAF Fighter Command during the Battle of Britain and is generally credited with playing a crucial role in Britain's defence, and hence, the defeat of Adolf Hitler's plan to invade Britain. Born in Moffat, Scotland, Dowding was an officer in the British Army in the 1900s and early 1910s. He joined the Royal Flying Corps at the start of the First World War and went on to serve as a fighter pilot and then as commanding officer of No. 16 Squadron. During the inter-war years he became Air Officer Commanding Fighting Area, Air Defence of Great Britain and then joined the Air Council as Air Member for Supply and Research. In July 1936, Dowding was appointed chief of the newly created RAF Fighter Command. During the Battle of Britain in the Second World War, Dowding's Fighter Command successfully defended the ... [...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] |
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] |
Royal Aircraft Establishment
The Royal Aircraft Establishment (RAE) was a British research establishment, known by several different names during its history, that eventually came under the aegis of the Ministry of Defence (United Kingdom), UK Ministry of Defence (MoD), before finally losing its identity in mergers with other institutions. The first site was at Farnborough Airfield ("RAE Farnborough") in Hampshire to which was added a second site RAE Bedford (Bedfordshire) in 1946. In 1988 it was renamed the Royal Aerospace Establishment (RAE) before merging with other research entities to become part of the new Defence Research Agency in 1991. History In 1904–1906 the Army Balloon Factory, which was part of the Army School of Ballooning, under the command of Colonel James Templer (balloon aviator), James Templer, relocated from Aldershot to the edge of Farnborough Common in order to have enough space to inflate the new "dirigible balloon" or airship which was then under construction.Walker, P; Early Avi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sussex
Sussex (), from the Old English (), is a historic county in South East England that was formerly an independent medieval Anglo-Saxon kingdom. It is bounded to the west by Hampshire, north by Surrey, northeast by Kent, south by the English Channel, and divided for many purposes into the ceremonial counties of West Sussex and East Sussex. Brighton and Hove, though part of East Sussex, was made a unitary authority in 1997, and as such, is administered independently of the rest of East Sussex. Brighton and Hove was granted city status in 2000. Until then, Chichester was Sussex's only city. The Brighton and Hove built-up area is the 15th largest conurbation in the UK and Brighton and Hove is the most populous city or town in Sussex. Crawley, Worthing and Eastbourne are major towns, each with a population over 100,000. Sussex has three main geographic sub-regions, each oriented approximately east to west. In the southwest is the fertile and densely populated coastal plain. Nort ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
