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Pinetree Line
The Pinetree Line was a series of radar stations located across southern Canada at about the 50th parallel north, along with a number of other stations located on the Atlantic and Pacific coasts. Run by North American Aerospace Defense Command (NORAD) (after its creation), over half were staffed by United States Air Force personnel with the balance operated by the Royal Canadian Air Force. The line was the first coordinated system for early detection of a Soviet bomber attack on North America. Its radar technology quickly became outdated, and the line was in full operation only for a short time. History Plans for what would become the Pinetree Line were underway as early as 1946 within the Permanent Joint Board on Defense (PJBD), a Canadian-U.S. organization. However, the costs of running such a system in the post-war era was too high, and instead Canada concentrated on the areas around Ontario and Quebec, while the United States set up stations in the Midwest and alon ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Royal Canadian Air Force
The Royal Canadian Air Force (RCAF; ) is the air and space force of Canada. Its role is to "provide the Canadian Forces with relevant, responsive and effective airpower". The RCAF is one of three environmental commands within the unified Canadian Armed Forces. As of 2020, the Royal Canadian Air Force consists of 12,074 Regular Force and 1,969 Primary Reserve personnel, supported by 1,518 civilians, and operates 258 manned aircraft and nine unmanned aerial vehicles. Lieutenant-General Eric Kenny is the current Commander of the Royal Canadian Air Force and Chief of the Air Force Staff. The Royal Canadian Air Force is responsible for all aircraft operations of the Canadian Forces, enforcing the security of Canada's airspace and providing aircraft to support the missions of the Royal Canadian Navy and the Canadian Army. The RCAF is a partner with the United States Air Force in protecting continental airspace under the North American Aerospace Defense Command (NORAD). The RCA ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
53rd Parallel North
Following are circles of latitude between the 50th parallel north and the 55th parallel north: 51st parallel north The 51st parallel north is a circle of latitude that is 51 degree (angle), degrees true north, north of the Earth, Earth's equator, equatorial plane. It crosses Europe, Asia, the Pacific Ocean, North America, and the Atlantic Ocean. At this latitude the sun is visible for 16 hours, 33 minutes during the summer solstice and 7 hours, 55 minutes during the winter solstice. Capital cities between the 51st and 52nd parallels are London and Astana. Russian America 1799–1824/25 In 1799 Paul I of Russia, Paul I, Tsar of the Russian Empire, issued a ''ukase'' creating the Russian-American Company (RAC). It was granted monopolistic control north of the 55th parallel north, which had been the Russian claim since 1790, as well as the right to operate and occupy territory to the south as long as the lands had not been previously occupied, or dependent on any other nation. In ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Distant Early Warning Line
The Distant Early Warning Line, also known as the DEW Line or Early Warning Line, was a system of radar stations in the northern Arctic region of Canada, with additional stations along the north coast and Aleutian Islands of Alaska (see List of White Alice Communications System sites#Project Stretchout sites, Project Stretchout and List of White Alice Communications System sites#Project Bluegrass sites, Project Bluegrass), in addition to the Faroe Islands, Greenland, and Iceland. It was set up to detect incoming bombers of the Soviet Union during the Cold War, and provide early warning of any sea-and-land invasion. The DEW Line was the northernmost and most capable of three radar lines in Canada and Alaska. The first of these was the joint Canadian-United States Pinetree Line, which ran from Newfoundland (island), Newfoundland to Vancouver Island just north of the Canada–United States border, but even while it was being built there were concerns that it would not provide enou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alaska
Alaska ( ) is a non-contiguous U.S. state on the northwest extremity of North America. Part of the Western United States region, it is one of the two non-contiguous U.S. states, alongside Hawaii. Alaska is also considered to be the northernmost, westernmost, and easternmost (the Aleutian Islands cross the 180th meridian into the eastern hemisphere) state in the United States. It borders the Canadian territory of Yukon and the province of British Columbia to the east. It shares a western maritime border, in the Bering Strait, with Russia's Chukotka Autonomous Okrug. The Chukchi and Beaufort Seas of the Arctic Ocean lie to the north, and the Pacific Ocean lies to the south. Technically, it is a semi-exclave of the U.S., and is the largest exclave in the world. Alaska is the largest U.S. state by area, comprising more total area than the following three largest states of Texas, California, and Montana combined, and is the seventh-largest subnational division i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Northern Canada
Northern Canada (), colloquially the North or the Territories, is the vast northernmost region of Canada, variously defined by geography and politics. Politically, the term refers to the three Provinces_and_territories_of_Canada#Territories, territories of Canada: Yukon, Northwest Territories and Nunavut. This area covers about 48 per cent of Canada's total land area, but has less than 0.5 per cent of demographics of Canada, Canada's population. The terms "northern Canada" or "the North" may be used in contrast with ''the far north'', which may refer to the Canadian Arctic, the portion of Canada that lies north of the Arctic Circle, east of Alaska and west of Greenland. However, in many other uses the two areas are treated as a single unit. Capitals The capital cities of the three northern territories, from west to east, are: * Yukon - Whitehorse * Northwest Territories - Yellowknife * Nunavut - Iqaluit Definitions Subdivisions As a social rather than political region, the C ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mid-Canada Line
The Mid-Canada Line (MCL), also known as the McGill Fence, was a line of radar stations running east–west across the middle of Canada, used to provide early warning of a Soviet bomber attack on North America. It was built to supplement the Pinetree Line, which was located farther south. The majority of Mid-Canada Line stations were used only briefly from the late 1950s to the mid-1960s, as the attack threat changed from bombers to ICBMs. As the MCL was closed down, the early warning role passed almost entirely to the newer and more capable DEW Line farther north. The MCL was based on the bistatic radar principle, using separated transmitters and receivers. An aircraft flying anywhere between the stations would reflect some of the transmitted signal towards the receiver, where it would mix with the signal travelling directly from the transmitter. The mixing of the two signals produces a pattern that is very easy to detect using simple electronics. As the transmitter is not ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bistatic Radar
Bistatic radar is a radar system comprising a transmitter and receiver that are separated by a distance comparable to the expected target distance. Conversely, a conventional radar in which the transmitter and receiver are co-located is called a monostatic radar. A system containing multiple spatially diverse monostatic or bistatic radar components with a shared area of coverage is called '' multistatic radar''. Many long-range air-to-air and surface-to-air missile systems use semi-active radar homing, which is a form of bistatic radar. Types Pseudo-monostatic radars Some radar systems may have separate transmit and receive antennas, but if the angle subtended between transmitter, target and receiver (the bistatic angle) is close to zero, then they would still be regarded as monostatic or pseudo-monostatic. For example, some very long range HF radar systems may have a transmitter and receiver which are separated by a few tens of kilometres for electrical isolation, but as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Doppler Radar
A Doppler radar is a specialized radar that uses the Doppler effect to produce velocity data about objects at a distance. It does this by bouncing a microwave signal off a desired target and analyzing how the object's motion has altered the frequency of the returned signal. This variation gives direct and highly accurate measurements of the radial component of a target's velocity relative to the radar. The term applies to radar systems in many domains like aviation, police radar detectors, navigation, meteorology, etc. Concept Doppler effect The Doppler effect (or Doppler shift), named after Austrian physicist Christian Doppler who proposed it in 1842, is the difference between the observed frequency and the emitted frequency of a wave for an observer moving relative to the source of the waves. It is commonly heard when a vehicle sounding a siren approaches, passes and recedes from an observer. The received frequency is higher (compared to the emitted frequency) during ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jet Engine
A jet engine is a type of reaction engine, discharging a fast-moving jet (fluid), jet of heated gas (usually air) that generates thrust by jet propulsion. While this broad definition may include Rocket engine, rocket, Pump-jet, water jet, and hybrid propulsion, the term typically refers to an internal combustion airbreathing jet engine, air-breathing jet engine such as a turbojet, turbofan, ramjet, pulse jet engine, pulse jet, or scramjet. In general, jet engines are internal combustion engines. Air-breathing jet engines typically feature a Axial compressor, rotating air compressor powered by a turbine, with the leftover power providing thrust through the propelling nozzle—this process is known as the Brayton cycle, Brayton thermodynamic cycle. Jet aircraft use such engines for long-distance travel. Early jet aircraft used turbojet engines that were relatively inefficient for subsonic flight. Most modern subsonic jet aircraft use more complex High-bypass turbofan, high-bypas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carcinotron
A backward wave oscillator (BWO), also called carcinotron or backward wave tube, is a vacuum tube that is used to generate microwaves up to the Terahertz radiation, terahertz range. Belonging to the traveling-wave tube family, it is an electronic oscillator, oscillator with a wide electronic tuning range. An electron gun generates an electron beam that interacts with a slow-wave structure. It sustains the oscillations by propagating a traveling wave backwards against the beam. The generated electromagnetic wave power has its group velocity directed oppositely to the direction of motion of the electrons. The output power is coupled out near the electron gun. It has two main subtypes, the M-type (M-BWO), the most powerful, and the O-type (O-BWO). The output Power (physics), power of the O-type is typically in the range of 1 Watt, mW at 1000 GHz to 50 mW at 200 Hertz, GHz. Carcinotrons are used as powerful and stable microwave sources. Due to the good quality wavefront ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Clutter (radar)
Clutter is the unwanted return (echoes) in electronic systems, particularly in reference to radars. Such echoes are typically returned from ground, sea, rain, animals/insects, chaff and atmospheric turbulences, and can cause serious performance issues with radar systems. What one person considers to be unwanted clutter, another may consider to be a wanted target. However, targets usually refer to point scatterers and clutter to extended scatterers (covering many range, angle, and Doppler cells). The clutter may fill a volume (such as rain) or be confined to a surface (like land). A knowledge of the volume or surface area illuminated is required to estimated the echo per unit volume, η, or echo per unit surface area, σ° (the radar backscatter coefficient). Causes Clutter may be caused by man-made objects such as buildings and — intentionally — by radar countermeasures such as chaff. Other causes include natural objects such as terrain features, sea, precipitation, hail ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Saint Anthony Air Station Aerial View July 1961
In Christian belief, a saint is a person who is recognized as having an exceptional degree of holiness, likeness, or closeness to God. However, the use of the term ''saint'' depends on the context and denomination. In Anglican, Oriental Orthodox, and Lutheran doctrine, all of their faithful deceased in Heaven are considered to be saints, but a selected few are considered worthy of greater honor or emulation. Official ecclesiastical recognition, and veneration, is conferred on some denominational saints through the process of canonization in the Catholic Church or glorification in the Eastern Orthodox Church after their approval. In many Protestant denominations, and following from Pauline usage, ''saint'' refers broadly to any holy Christian, without special recognition or selection. While the English word ''saint'' (deriving from the Latin ) originated in Christianity, historians of religion tend to use the appellation "in a more general way to refer to the state of special h ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
