|
MOD Chicksands
Ministry of Defence Chicksands, or more simply MOD Chicksands, is a tri-service British Armed Forces facility in Bedfordshire, approximately north of London. It is named after Chicksands Priory, a 12th-century Gilbertine monastery located within the perimeter of the camp. The site was formerly RAF Chicksands, which closed in 1997, handing over control of the site to the British Army. Today, the Defence Intelligence Training Group (DITG) is based at MOD Chicksands, and is the Headquarters of the Intelligence Corps. The base will close and be disposed of in 2030. Site history RAF Chicksands The Crown Commissioners bought the Chicksands estate on 15 April 1936, later renting it to Gerald Bagshawe, who lived there until it was requisitioned by the Royal Navy. After nine months the RAF took over operations and established a signal intelligence collection (SIGINT) unit there, known as a Y Station. The site operated as a SIGINT collection site throughout the Second World War, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shefford, Bedfordshire
Shefford is a town and civil parishes in England, civil parish in the Central Bedfordshire district of Bedfordshire, England. At the 2021 census it had a population of 7,311. It lies south-east of Bedford. Toponymy The name Shefford means "sheep ford", referencing the fords over the River Flit and River Hit. The name was recorded as "Shipford" in 1229, with the modern spelling being recorded from as early as 1262. The town gives its name to Shefford, Quebec. History Roman remains were discovered in Shefford in the early nineteenth century. Shefford grew up between a pair of fords on the main road from Bedford to Hitchin where it crosses the River Flit and River Hit. Another road leading west from that main road, heading towards Ampthill, became the town's High Street. Both fords were later replaced by bridges; North Bridge over the Flit and South Bridge over the Hit. A market was being held at Shefford by 1225, with a formal market charter being issued in 1229. In 1312, ano ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Y-stations
The "Y" service was a network of British signals intelligence collection sites, the Y-stations. The service was established during the First World War and used again during the Second World War. The sites were operated by a range of agencies including the British Army, Army, Royal Navy, Navy and Royal Air Force, RAF, and the Foreign Office (MI6 and MI5). The General Post Office and the Marconi Company provided some receiving stations, ashore and afloat. There were more than 600 receiving sets in use at Y-stations during the Second World War. Role The "Y" name derived from Wireless Interception (WI). The stations tended to be one of two types, for intercepting the signals and for identifying where they were coming from. Sometimes both functions were operated at the same site, with the direction finding (D/F) hut being a few hundred metres from the main interception building to minimise interference. The sites collected radio traffic which was then either analysed locally or, if e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
A Medium View Of The Royal Air Force Chicksands Main Gate - DPLA - Faef88f91fefd4ca7d20306dc93ca398
A, or a, is the first letter and the first vowel letter of the Latin alphabet, used in the modern English alphabet, and others worldwide. Its name in English is '' a'' (pronounced ), plural ''aes''. It is similar in shape to the Ancient Greek letter alpha, from which it derives. The uppercase version consists of the two slanting sides of a triangle, crossed in the middle by a horizontal bar. The lowercase version is often written in one of two forms: the double-storey and single-storey . The latter is commonly used in handwriting and fonts based on it, especially fonts intended to be read by children, and is also found in italic type. In English, '' a'' is the indefinite article, with the alternative form ''an''. Name In English, the name of the letter is the ''long A'' sound, pronounced . Its name in most other languages matches the letter's pronunciation in open syllables. History The earliest known ancestor of A is ''aleph''—the first letter of the Phoenician ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Direction Finding
Direction finding (DF), radio direction finding (RDF), or radiogoniometry is the use of radio waves to determine the direction to a radio source. The source may be a cooperating radio transmitter or may be an inadvertent source, a naturally-occurring radio source, or an illicit or enemy system. Radio direction finding differs from radar in that only the direction is determined by any one receiver; a radar system usually also gives a distance to the object of interest, as well as direction. By triangulation, the location of a radio source can be determined by measuring its direction from two or more locations. Radio direction finding is used in radio navigation for ships and aircraft, to locate emergency transmitters for search and rescue, for tracking wildlife, and to locate illegal or interfering transmitters. During the Second World War, radio direction finding was used by both sides to locate and direct aircraft, surface ships, and submarines. RDF systems can be used w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
High Frequency
High frequency (HF) is the ITU designation for the band of radio waves with frequency between 3 and 30 megahertz (MHz). It is also known as the decameter band or decameter wave as its wavelengths range from one to ten decameters (ten to one hundred meters). Frequencies immediately below HF are denoted '' medium frequency'' (MF), while the next band of higher frequencies is known as the '' very high frequency'' (VHF) band. The HF band is a major part of the shortwave band of frequencies, so communication at these frequencies is often called ''shortwave radio''. Because radio waves in this band can be reflected back to Earth by the ionosphere layer in the atmosphere – a method known as "skip" or "skywave" propagation – these frequencies can be used for long-distance communication across intercontinental distances and for mountainous terrains which prevent line-of-sight communications. The band is used by international shortwave broadcasting stations (3.95–25.8 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antenna (electronics)
In radio-frequency engineering, an antenna (American English) or aerial (British English) is an electronic device that converts an alternating current, alternating electric current into radio waves (transmitting), or radio waves into an electric current (receiving). It is the interface between radio waves Radio propagation, propagating through space and electric currents moving in metal Electrical conductor, conductors, used with a transmitter or receiver (radio), receiver. In transmission (telecommunications), transmission, a radio transmitter supplies an electric current to the antenna's Terminal (electronics), terminals, and the antenna radiates the energy from the current as electromagnetic radiation, electromagnetic waves (radio waves). In receiver (radio), reception, an antenna intercepts some of the power of a radio wave in order to produce an electric current at its terminals, that is applied to a receiver to be amplifier, amplified. Antennas are essential components ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
AN/FLR-9
The AN/FLR-9 is a type of very large circularly disposed antenna array, built at eight locations during the Cold War for HF/DF direction finding of high priority targets. The worldwide network, known collectively as "''Iron Horse''", could locate HF communications almost anywhere on Earth. Because of the exceptionally large size of its outer reflecting screen (1056 vertical steel wires supported by 96 towers), the FLR-9 was commonly referred to by the nickname "Elephant Cage." Constructed in the early to mid 1960s, in May 2016 the last operational FLR-9 at Joint Base Elmendorf-Richardson in Alaska was decommissioned. It can be confused with the US Navy's AN/FRD-10, which also used a circularly disposed antenna array. Description In accordance with the Joint Electronics Type Designation System (JETDS), the "''AN/FLR-9''" designation represents the 9th design of an Army-Navy electronic device for fixed ground countermeasures passive detection equipment. The JETDS system al ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cold War
The Cold War was a period of global Geopolitics, geopolitical rivalry between the United States (US) and the Soviet Union (USSR) and their respective allies, the capitalist Western Bloc and communist Eastern Bloc, which lasted from 1947 until the dissolution of the Soviet Union in 1991. The term ''Cold war (term), cold war'' is used because there was no direct fighting between the two superpowers, though each supported opposing sides in regional conflicts known as proxy wars. In addition to the struggle for ideological and economic influence and an arms race in both conventional and Nuclear arms race, nuclear weapons, the Cold War was expressed through technological rivalries such as the Space Race, espionage, propaganda campaigns, Economic sanctions, embargoes, and sports diplomacy. After the end of World War II in 1945, during which the US and USSR had been allies, the USSR installed satellite state, satellite governments in its occupied territories in Eastern Europe and N ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lorenz Cipher
The Lorenz SZ40, SZ42a and SZ42b were German Rotor machine, rotor stream cipher machines used by the German Army (Wehrmacht), German Army during World War II. They were developed by C. Lorenz AG in Berlin. The model name ''SZ'' is derived from ''Schlüssel-Zusatz'', meaning ''cipher attachment''. The instruments implemented a Gilbert Vernam#The Vernam cipher, Vernam stream cipher. British cryptanalysts, who referred to encrypted German Electrical telegraph, teleprinter traffic as Fish (cryptography), ''Fish'', dubbed the machine and its traffic ''Tunny'' (meaning tunafish) and deduced its logical structure three years before they saw such a machine. The SZ machines were in-line attachments to standard teleprinters. An experimental link using SZ40 machines was started in June 1941. The enhanced SZ42 machines were brought into substantial use from mid-1942 onwards for high-level communications between the Oberkommando der Wehrmacht, German High Command in Wünsdorf close to Berlin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Enigma (machine)
The Enigma machine is a cipher device developed and used in the early- to mid-20th century to protect Commerce, commercial, diplomatic, and military communication. It was employed extensively by Nazi Germany during World War II, in all branches of the Wehrmacht, German military. The Enigma machine was considered so secure that it was used to encipher the most top-secret messages. The Enigma has an electromechanical Rotor machine, rotor mechanism that scrambles the 26 letters of the alphabet. In typical use, one person enters text on the Enigma's keyboard and another person writes down which of the 26 lights above the keyboard illuminated at each key press. If plaintext is entered, the illuminated letters are the ciphertext. Entering ciphertext transforms it back into readable plaintext. The rotor mechanism changes the electrical connections between the keys and the lights with each keypress. The security of the system depends on machine settings that were generally changed dail ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Axis Powers
The Axis powers, originally called the Rome–Berlin Axis and also Rome–Berlin–Tokyo Axis, was the military coalition which initiated World War II and fought against the Allies of World War II, Allies. Its principal members were Nazi Germany, Fascist Italy, Kingdom of Italy and the Empire of Japan. The Axis were united in their far-right positions and general opposition to the Allies, but otherwise lacked comparable coordination and ideological cohesion. The Axis grew out of successive diplomatic efforts by Germany, Italy, and Japan to secure their own specific expansionist interests in the mid-1930s. The first step was the Italo-German protocol of 23 October 1936, protocol signed by Germany and Italy in October 1936, after which Italian leader Benito Mussolini declared that all other European countries would thereafter rotate on the Rome–Berlin axis, thus creating the term "Axis". The following November saw the ratification of the Anti-Comintern Pact, an anti-communis ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
