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Leonard George Chapman
Squadron Leader Leonard George Chapman (28 March 1910 – 25 July 1975) was an inventor, radio engineer and Royal Air Force officer. While serving in the Royal Air Force he invented the 'Chapman Method' in 1937–1938.Burns, Russell, ed. Chapter 8Bawdsey Research Station, :File:Len Chapman Method Award.jpg, Memorandum This method accurately determines the location of an object from the time difference of arrival of a signal (possibly radio echo) emitted from that object to three or more receivers. A method commonly used in civil and military surveillance applications, and also known as Multilateration. Thus it has been suggested that Chapman be nominated as the father of Multilateration.Nicholas J. Willis, Hugh D. GriffithsPages 20–22 especially Note 10/ref> Chapman was in charge of installing 5 radar stations as part of the Chain Home system. Including the Netherbutton station in the parish of Holm, Mainland Orkney, Holm, Orkney Islands, the installation of which Chapman p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Squadron Leader
Squadron leader (Sqn Ldr in the RAF ; SQNLDR in the RAAF and RNZAF; formerly sometimes S/L in all services) is a commissioned rank in the Royal Air Force and the air forces of many countries which have historical British influence. It is also sometimes used as the English translation of an equivalent rank in countries which have a non-English air force-specific rank structure. An air force squadron leader ranks above flight lieutenant and immediately below wing commander and it is the most junior of the senior officer ranks. The air force rank of squadron leader has a NATO ranking code of OF-3, equivalent to a lieutenant-commander in the Royal Navy or a major in the British Army or the Royal Marines. The equivalent rank in the Women's Auxiliary Air Force, Women's Royal Air Force (until 1968) and Princess Mary's Royal Air Force Nursing Service (until 1980) was "squadron officer". Squadron leader has also been used as a cavalry command appointment (UK) and rank (France) since ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alan Turing
Alan Mathison Turing (; 23 June 1912 – 7 June 1954) was an English mathematician, computer scientist, logician, cryptanalyst, philosopher, and theoretical biologist. Turing was highly influential in the development of theoretical computer science, providing a formalisation of the concepts of algorithm and computation with the Turing machine, which can be considered a model of a general-purpose computer. He is widely considered to be the father of theoretical computer science and artificial intelligence. Born in Maida Vale, London, Turing was raised in southern England. He graduated at King's College, Cambridge, with a degree in mathematics. Whilst he was a fellow at Cambridge, he published a proof demonstrating that some purely mathematical yes–no questions can never be answered by computation and defined a Turing machine, and went on to prove that the halting problem for Turing machines is undecidable. In 1938, he obtained his PhD from the Department of Mathemati ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bletchley Park
Bletchley Park is an English country house and estate in Bletchley, Milton Keynes ( Buckinghamshire) that became the principal centre of Allied code-breaking during the Second World War. The mansion was constructed during the years following 1883 for the financier and politician Sir Herbert Leon in the Victorian Gothic, Tudor, and Dutch Baroque styles, on the site of older buildings of the same name. During World War II, the estate housed the Government Code and Cypher School (GC&CS), which regularly penetrated the secret communications of the Axis Powersmost importantly the German Enigma and Lorenz ciphers. The GC&CS team of codebreakers included Alan Turing, Gordon Welchman, Hugh Alexander, Bill Tutte, and Stuart Milner-Barry. The nature of the work at Bletchley remained secret until many years after the war. According to the official historian of British Intelligence, the "Ultra" intelligence produced at Bletchley shortened the war by two to four years, and without it th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Winifred Margaret Chapman
Winifred is a feminine given name, an anglicization of Welsh ''Gwenffrewi'', from ''gwen'', "fair", and ''ffrew'', "stillness". It may refer to: People * Saint Winifred * Winifred Atwell (1914–1983), a pianist who enjoyed great popularity in Britain in the 1950s with a series of boogie woogie and ragtime hits * Winifred Mitchell Baker (born 1957), better known simply as Mitchell Baker, the "Chief Lizard Wrangler" and the President of the Mozilla Corporation * Winifred, Countess of Dundonald, wife of Douglas Cochrane, 12th Earl of Dundonald * Winifred Brunton (1880-1959), a painter from South Africa most famous for her haunting portraits of Egyptian pharaohs * Winifred Cavendish-Bentinck, Duchess of Portland (née ''Dallas-Yorke;'' 1863–1954), wife of William Cavendish-Bentinck, 6th Duke of Portland * Winifred Copperwheat (19051976), English violist *Winifred Starr Dobyns (18861963), American suffragist and landscape designer * Dr. Winifred Margaret 'Winnie' Ewing (born 1929 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Satellite Watching
Satellite watching or satellite spotting is a hobby which consists of the observation and tracking of artificial satellites that are orbiting Earth. People with this hobby are variously called satellite watchers, trackers, spotters, observers, etc. Since satellites outside Earth's shadow reflect sunlight, those especially in low Earth orbit may visibly glint (or "flare") as they traverse the observer's sky, usually during twilight. History Amateur satellite spotting traces back to the days of early artificial satellites when the Smithsonian Astrophysical Observatory launched the Operation Moonwatch program in 1956 to enlist amateur astronomers in an early citizen science effort to track Soviet ''sputniks''. The program was an analog to the World War II Ground Observer Corps citizen observation program to spot enemy bombers. Moonwatch was crucial until professional stations were deployed in 1958. The program was discontinued in 1975. The people who had been involved continu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Winifred Leonard And Dora
Winifred is a feminine given name, an anglicization of Welsh ''Gwenffrewi'', from ''gwen'', "fair", and ''ffrew'', "stillness". It may refer to: People * Saint Winifred * Winifred Atwell (1914–1983), a pianist who enjoyed great popularity in Britain in the 1950s with a series of boogie woogie and ragtime hits * Winifred Mitchell Baker (born 1957), better known simply as Mitchell Baker, the "Chief Lizard Wrangler" and the President of the Mozilla Corporation * Winifred, Countess of Dundonald, wife of Douglas Cochrane, 12th Earl of Dundonald * Winifred Brunton (1880-1959), a painter from South Africa most famous for her haunting portraits of Egyptian pharaohs * Winifred Cavendish-Bentinck, Duchess of Portland (née ''Dallas-Yorke;'' 1863–1954), wife of William Cavendish-Bentinck, 6th Duke of Portland * Winifred Copperwheat (19051976), English violist *Winifred Starr Dobyns (18861963), American suffragist and landscape designer * Dr. Winifred Margaret 'Winnie' Ewing (born 1929 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Satellite
A satellite or artificial satellite is an object intentionally placed into orbit in outer space. Except for passive satellites, most satellites have an electricity generation system for equipment on board, such as solar panels or radioisotope thermoelectric generators (RTGs). Most satellites also have a method of communication to ground stations, called Transponder (satellite communications), transponders. Many satellites use a Satellite bus, standardized bus to save cost and work, the most popular of which is small CubeSats. Similar satellites can work together as a group, forming Satellite constellation, constellations. Because of the high launch cost to space, satellites are designed to be as lightweight and robust as possible. Most communication satellites are radio Broadcast relay station, relay stations in orbit and carry dozens of transponders, each with a bandwidth of tens of megahertz. Satellites are placed from the surface to orbit by launch vehicles, high enough to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Operation Sea Lion
Operation Sea Lion, also written as Operation Sealion (german: Unternehmen Seelöwe), was Nazi Germany's code name for the plan for an invasion of the United Kingdom during the Battle of Britain in the Second World War. Following the Battle of France, Adolf Hitler, the German Führer and Supreme Commander of the Armed Forces, hoped the British government would accept his offer to end the war, and he reluctantly considered invasion only as a last resort if all other options failed. As a precondition, Hitler specified the achievement of both air and naval superiority over the English Channel and the proposed landing sites, but the German forces did not achieve either at any point during the war, and both the German High Command and Hitler himself had serious doubts about the prospects for success. Nevertheless, both the German Army and Navy undertook a major programme of preparations for an invasion: training troops, developing specialised weapons and equipment, and modifyin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
