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Alec Reeves
Alec Harley Reeves (10 March 1902 – 13 October 1971) was a British scientist best known for his invention of pulse-code modulation (PCM). He was awarded 82 patents. Early life Alec Reeves was born in Redhill, Surrey in 1902 and was educated at the Reigate Grammar School, followed by a scholarship to the City and Guilds Engineering College in 1918, and then postgraduate studies at Imperial College London in 1921. Career Reeves joined the International Western Electric Company in 1923, and was part of a team of engineers responsible for the first commercial transatlantic telephone link. In 1925 Western Electric's European operations were acquired by ITT, and in 1927 Reeves was transferred to ITT's research laboratories in Paris. Whilst in Paris, he was responsible for a number of projects, including: a short-wave radio link between the telephone networks of Spain and South America, the world's first single-sideband radio telephone system, and for developing a multi-channel carr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pulse-code Modulation
Pulse-code modulation (PCM) is a method used to digitally represent sampled analog signals. It is the standard form of digital audio in computers, compact discs, digital telephony and other digital audio applications. In a PCM stream, the amplitude of the analog signal is sampled regularly at uniform intervals, and each sample is quantized to the nearest value within a range of digital steps. Linear pulse-code modulation (LPCM) is a specific type of PCM in which the quantization levels are linearly uniform. This is in contrast to PCM encodings in which quantization levels vary as a function of amplitude (as with the A-law algorithm or the μ-law algorithm). Though ''PCM'' is a more general term, it is often used to describe data encoded as LPCM. A PCM stream has two basic properties that determine the stream's fidelity to the original analog signal: the sampling rate, which is the number of times per second that samples are taken; and the bit depth, which determines the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Franklin D
Franklin may refer to: People * Franklin (given name) * Franklin (surname) * Franklin (class), a member of a historical English social class Places Australia * Franklin, Tasmania, a township * Division of Franklin, federal electoral division in Tasmania * Division of Franklin (state), state electoral division in Tasmania * Franklin, Australian Capital Territory, a suburb in the Canberra district of Gungahlin * Franklin River, river of Tasmania * Franklin Sound, waterway of Tasmania Canada * District of Franklin, a former district of the Northwest Territories * Franklin, Quebec, a municipality in the Montérégie region * Rural Municipality of Franklin, Manitoba * Franklin, Manitoba, an unincorporated community in the Rural Municipality of Rosedale, Manitoba * Franklin Glacier Complex, a volcano in southwestern British Columbia * Franklin Range, a mountain range on Vancouver Island, British Columbia * Franklin River (Vancouver Island), British Columbia * Franklin Strai ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
George Hockham
George Alfred Hockham FREng FIET (7 December 1938 – 16 September 2013) was a British engineer. He worked for over 40 years in theoretical analysis and design techniques applied to the solution of electromagnetic problems covering many different antenna types for radar, electronic warfare and communication systems. He coauthored the original paper on the application of cladded glass fibre as a transmission medium. Biography Born in Epsom, Surrey, Hockham received a BSc (Eng) degree from the Regent Street Polytechnic in 1961, and a PhD in 1969 from the Queen Mary University of London. He worked for over 40 years in theoretical analysis and design techniques applied to the solution of electromagnetic problems covering many different antenna types for radar, electronic warfare and communication systems. Hockham also contributed significantly to the development of optical fibres for long distance communications systems. He proposed and published, together with a colleague Profe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Charles K
Charles is a masculine given name predominantly found in English and French speaking countries. It is from the French form ''Charles'' of the Proto-Germanic name (in runic alphabet) or ''*karilaz'' (in Latin alphabet), whose meaning was "free man". The Old English descendant of this word was '' Ċearl'' or ''Ċeorl'', as the name of King Cearl of Mercia, that disappeared after the Norman conquest of England. The name was notably borne by Charlemagne (Charles the Great), and was at the time Latinized as ''Karolus'' (as in ''Vita Karoli Magni''), later also as '' Carolus''. Some Germanic languages, for example Dutch and German, have retained the word in two separate senses. In the particular case of Dutch, ''Karel'' refers to the given name, whereas the noun ''kerel'' means "a bloke, fellow, man". Etymology The name's etymology is a Common Germanic noun ''*karilaz'' meaning "free man", which survives in English as churl (< Old English ''ċeorl''), which developed its depr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
RAF Bomber Command
RAF Bomber Command controlled the Royal Air Force's bomber forces from 1936 to 1968. Along with the United States Army Air Forces, it played the central role in the strategic bombing of Germany in World War II. From 1942 onward, the British bombing campaign against Germany became less restrictive and increasingly targeted industrial sites and the civilian manpower base essential for German war production. In total 364,514 operational sorties were flown, 1,030,500 tons of bombs were dropped and 8,325 aircraft lost in action. Bomber Command crews also suffered a high casualty rate: 55,573 were killed out of a total of 125,000 aircrew, a 44.4% death rate. A further 8,403 men were wounded in action, and 9,838 became prisoners of war. Bomber Command stood at the peak of its post-war military power in the 1960s, the V bombers holding the United Kingdom's nuclear deterrent and a supplemental force of Canberra light bombers. In August 2006, a memorial was unveiled at Lincoln Cathe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Royal Air Force
The Royal Air Force (RAF) is the United Kingdom's air and space force. It was formed towards the end of the First World War on 1 April 1918, becoming the first independent air force in the world, by regrouping the Royal Flying Corps (RFC) and the Royal Naval Air Service (RNAS). Following the Allied victory over the Central Powers in 1918, the RAF emerged as the largest air force in the world at the time. Since its formation, the RAF has taken a significant role in British military history. In particular, it played a large part in the Second World War where it fought its most famous campaign, the Battle of Britain. The RAF's mission is to support the objectives of the British Ministry of Defence (MOD), which are to "provide the capabilities needed to ensure the security and defence of the United Kingdom and overseas territories, including against terrorism; to support the Government's foreign policy objectives particularly in promoting international peace and security". The R ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oboe (navigation)
Oboe was a British bomb aiming system developed to allow their aircraft to bomb targets accurately in any type of weather, day or night. Oboe coupled radar tracking with radio transponder technology. The guidance system used two well separated radar stations to track the aircraft. Each Oboe tracking station used radio ranging to define a circle, the radius of which was the distance from the station to the target, the third point in the triangulation. The two circles intersected at the target. Radar pulses from each station were picked up by a transponder mounted in the aircraft. The aircraft transponder transmitted the signals back to the stations, after a slight delay. By assessing the time it took for the signal to return the distance between the station and the aircraft could be determined. One tracking station, the Cat station, was used to adjust the aircraft's flight path. The other station, the Mouse, was used to key the bomb release point. Oboe, in essence, was a ground- ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Francis Jones (physicist)
Francis Edgar Jones MBE FRS, (16 January 1914 – 10 April 1988) was a British physicist who co-developed the Oboe blind bombing system. Education Jones was born in Wolverhampton, the son of a teacher. In 1921 the family moved to Dagenham, Essex, where he attended the Royal Liberty School at Romford. He then attended King's College London. Research During World War II Jones worked in the Telecommunications Research Establishment (TRE) and collaborated with Alec Harley Reeves to develop the Oboe blind bombing system. After the war he directed investigations in the Basic Research Division of TRE on the detection and properties of infra-red and millimetre-wave radiation. He also made very accurate measurements of propagation velocity of electro-magnetic radiation at radio frequencies and studied applications of radar in meteorology. He became Deputy Head of the Division (later renamed the Physics Department, Royal Radar Establishment) In 1953, as Chief Scientific Officer and Depu ... [...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] |
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] |
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] |
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] |
