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Outpost To Bletchley Park
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 Army, Navy and 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 encrypted, passed for processing initially ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Signals Intelligence
Signals intelligence (SIGINT) is the act and field of intelligence-gathering by interception of ''signals'', whether communications between people (communications intelligence—abbreviated to COMINT) or from electronic signals not directly used in communication (electronic intelligence—abbreviated to ELINT). As classified and sensitive information is usually encrypted, signals intelligence may necessarily involve cryptanalysis (to decipher the messages). Traffic analysis—the study of who is signaling to whom and in what quantity—is also used to integrate information, and it may complement cryptanalysis. History Origins Electronic interceptions appeared as early as 1900, during the Boer War of 1899–1902. The British Royal Navy had installed wireless sets produced by Marconi on board their ships in the late 1890s, and the British Army used some limited wireless signalling. The Boers captured some wireless sets and used them to make vital transmissions. Since the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Landline
A landline is a physical telephone connection that uses metal wires or optical fiber from the subscriber's premises to the network, allowing multiple phones to operate simultaneously on the same phone number. It is also referred to as plain old telephone service (POTS), twisted pair, telephone line, or public switched telephone network (PSTN). Landline services are traditionally provided via an analogue copper wire to a telephone exchange. ''Landline service'' is usually distinguished from more modern forms of telephone services which use Internet Protocol based services over optical fiber ( Fiber-to-the-x), or other broadband services ( VDSL/Cable) using Voice over IP. However, sometimes modern fixed phone services delivered over a fixed internet connection are referred to as a "landline" (i.e., non-cellular service). Characteristics Landline service is typically provided through the outside plant of a telephone company's central office, or wire center. The outside plant ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Goonhavern
Goonhavern () is a village in Cornwall, England, in the civil parish of Perranzabuloe. It is located along the A3075 road, about two miles east of Perranporth. As well as a village store and post office, a garden centre and several campsites, there is a public house named 'The New Inn' in the centre of the village. Until recently, a model village was a visitor attraction beside the B3285 southeast of Goonhavern. A traditional village show is held in the community hall in July, with prizes awarded for the local produce, flower arrangements, art, craft and photography. The name Goonhavern comes from the Cornish words ''goon'', meaning 'downs', and ''havar'', meaning 'summer fallow land'. History A railway branch-line to Perranporth and St Agnes ran through Goonhavern from c.1905 but the line was closed as part of the Beeching cuts and today there is little sign of its route through the village centre. On 12 July 1940, during the Battle of Britain, three bombs were dropped ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Goniometer
A goniometer is an instrument that either measures an angle or allows an object to be rotated to a precise angular position. The term goniometry derives from two Greek words, γωνία (''gōnía'') 'angle' and μέτρον (''métron'') ' measure'. The protractor is a commonly used type in the fields of mechanics, engineering, and geometry. The first known description of a goniometer, based on the astrolabe, was by Gemma Frisius in 1538. Protractor A protractor is a measuring instrument, typically made of transparent plastic, for measuring angles. Some protractors are simple half-discs or full circles. More advanced protractors, such as the bevel protractor, have one or two swinging arms, which can be used to help measure the angle. Most protractors measure angles in degrees (°). Radian-scale protractors measure angles in radians. Most protractors are divided into 180 equal parts. Some precision protractors further divide degrees into arcminutes. A protractor divided ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Points Of The Compass
The points of the compass are a set of horizontal, Radius, radially arrayed compass directions (or Azimuth#In navigation, azimuths) used in navigation and cartography. A ''compass rose'' is primarily composed of four cardinal directions—north, east, south, and west—each separated by 90 degree (angle), degrees, and secondarily divided by four ordinal (intercardinal) directions—northeast, southeast, southwest, and northwest—each located halfway between two cardinal directions. Some disciplines such as meteorology and navigation further divide the compass with additional azimuths. Within European tradition, a fully defined compass has 32 "points" (and any finer subdivisions are described in fractions of points). Compass points or compass directions are valuable in that they allow a user to refer to a specific azimuth in a Colloquialism, colloquial fashion, without having to compute or remember degrees. Designations The names of the compass point directions follow these r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Adcock Antenna
The Adcock antenna is an antenna array consisting of four equidistant vertical elements which can be used to transmit or receive directional radio waves. The Adcock array was invented and patented by British engineer Frank Adcock and since his August 1919 British Patent No. 130,490, the 'Adcock Aerial' has been used for a variety of applications, both civilian and military. (Note: The patent lawyer's name appears as inventor, with "F. Adcock" in parentheses, since Lt. Adcock, Royal Engineers(RE) Service Number 33962 was serving in wartime France at the time.) Although originally conceived for receiving low frequency (LF) waves, it has also been used for transmitting, and has since been adapted for use at much higher frequencies, up to ultra high frequency (UHF). In the early 1930s, the Adcock antenna (transmitting in the LF/MF bands) became a key feature of the newly created radio navigation system for aviation. The low frequency radio range (LFR) network, w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Allies In World War II
The Allies, formally referred to as the United Nations from 1942, were an international military coalition formed during World War II (1939–1945) to oppose the Axis powers. Its principal members were the " Big Four" – the United Kingdom, United States, Soviet Union, and China. Membership in the Allies varied during the course of the war. When the conflict broke out on 1 September 1939, the Allied coalition consisted of the United Kingdom, France, and Poland, as well as their respective dependencies, such as British India. They were joined by the independent dominions of the British Commonwealth: Canada, Australia, New Zealand and South Africa. Consequently, the initial alliance resembled that of the First World War. As Axis forces began invading northern Europe and the Balkans, the Allies added the Netherlands, Belgium, Norway, Greece, and Yugoslavia. The Soviet Union, which initially had a nonaggression pact with Germany and participated in its invasion of Poland, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Admiral Dönitz
Admiral is one of the highest ranks in many navies. In the Commonwealth nations and the United States, a "full" admiral is equivalent to a "full" general in the army or the air force. Admiral is ranked above vice admiral and below admiral of the fleet, or fleet admiral. Etymology The word in Middle English comes from Anglo-French , "commander", from Medieval Latin , . These evolved from the Arabic () – () (), "king, prince, chief, leader, nobleman, lord, a governor, commander, or person who rules over a number of people" and (), the Arabic definite article meaning "the." In Arabic, admiral is also represented as (), where al-Baḥr (البحر) means the sea. The 1818 edition of Samuel Johnson's ''A Dictionary of the English Language'', edited and revised by the Rev. Henry John Todd, states that the term "has been traced to the Arab. emir or amir, lord or commander, and the Gr. , the sea, q. d. ''prince of the sea''. The word is written both with and without the d, in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
U-boats
U-boats are naval submarines operated by Germany, including during the First and Second World Wars. The term is an anglicized form of the German word , a shortening of (), though the German term refers to any submarine. Austro-Hungarian Navy submarines were also known as U-boats. U-boats are most known for their unrestricted submarine warfare in both world wars, trying to disrupt merchant traffic towards the UK and force the UK out of the war. In World War I, Germany intermittently waged unrestricted submarine warfare against the UK: a first campaign in 1915 was abandoned after strong protests from the US but in 1917 the Germans, facing deadlock on the continent, saw no other option than to resume the campaign in February 1917. The renewed campaign failed to achieve its goal mainly because of the introduction of convoys. Instead the campaign ensured final defeat as the campaign was a contributing factor to the entry of the US in the First World War. In World War II, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Battle Of The Atlantic
The Battle of the Atlantic, the longest continuous military campaign in World War II, ran from 1939 to the defeat of Nazi Germany in 1945, covering a major part of the naval history of World War II. At its core was the Allies of World War II, Allied naval Blockade of Germany (1939–1945), blockade of Germany, announced the day after the declaration of war, and Germany's subsequent counter-blockade. The campaign peaked from mid-1940 to the end of 1943. The Battle of the Atlantic pitted U-boats and other warships of the German (navy) and aircraft of the (air force) against the Royal Navy, Royal Canadian Navy, United States Navy, and Merchant Navy (United Kingdom), Allied merchant shipping. Convoys, coming mainly from North America and predominantly going to the United Kingdom and the Soviet Union, were protected for the most part by the British and Canadian navies and air forces. These forces were aided by ships and aircraft of the United States beginning on 13 September 1941. ... [...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 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. In earlier RDF systems, the operator mechanically rotated a loop antenna or solenoid and listened for peaks or nulls in the signal to determine the bearing to the transmitter. This took considerable time, on the order of a minute or more. Radio operators could avoid being located by keeping their messag ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Delhi
Delhi, officially the National Capital Territory (NCT) of Delhi, is a city and a union territory of India containing New Delhi, the capital of India. Straddling the Yamuna river, but spread chiefly to the west, or beyond its Bank (geography), right bank, Delhi shares borders with the state of Uttar Pradesh in the east and with the state of Haryana in the remaining directions. Delhi became a union territory on 1 November 1956 and the NCT in 1995. The NCT covers an area of . According to the 2011 census, Delhi's city proper population was over 11 million, while the NCT's population was about 16.8 million. The topography of the medieval fort Purana Qila on the banks of the river Yamuna matches the literary description of the citadel Indraprastha in the Sanskrit epic ''Mahabharata''; however, excavations in the area have revealed no signs of an ancient built environment. From the early 13th century until the mid-19th century, Delhi was the capital of two major empires, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
