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Early-warning Radar
An early-warning radar is any radar system used primarily for the long-range detection of its targets, i.e., allowing defences to be alerted as ''early'' as possible before the intruder reaches its target, giving the air defences the maximum time in which to operate. This contrasts with systems used primarily for tracking or gun laying, which tend to offer shorter ranges but offer much higher accuracy. EW radars tend to share a number of design features that improve their performance in the role. For instance, EW radar typically operates at lower frequencies, and thus longer wavelengths, than other types. This greatly reduces their interaction with rain and snow in the air, and therefore improves their performance in the long-range role where their coverage area will often include precipitation. This also has the side-effect of lowering their optical resolution, but this is not important in this role. Likewise, EW radars often use much lower pulse repetition frequency to maximi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
PAVE PAWS Radar Clear AFS Alaska
PAVE is a United States Air Force program identifier relating to electronic systems. Prior to 1979, Pave was said to be a code word for the Air Force unit responsible for the project. ''Pave'' was used as an inconsequential prefix identifier for a wide range of different programs, though backronyms and alternative meanings have been used. For example, in the helicopters Pave Low and Pave Hawk it was said to mean ''Precision Avionics Vectoring Equipment'', but in PAVE PAWS it was said to mean ''Precision Acquisition Vehicle Entry''. PAVE systems * Pave Eagle – Modified Beechcraft Bonanza drone aircraft for low altitude sensor monitoring. * Pave Hawk – Sikorsky HH-60 Pave Hawk special operations and combat search and rescue helicopter. * Pave Nail - OV-10 Bronco with Pave Spot target laser designator pod. * Pave Knife – Ford Aerospace AN/AVQ-10 Pave Knife early laser targeting pod. * Pave Low – Sikorsky MH-53 Pave Low special ops and combat search and rescue helicopt ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shortwave Radio
Shortwave radio is radio transmission using radio frequencies in the shortwave bands (SW). There is no official definition of the band range, but it always includes all of the High frequency, high frequency band (HF), which extends from 3 to 30 MHz (approximately 100 to 10 metres in wavelength). It lies between the Medium frequency, medium frequency band (MF) and the bottom of the Very high frequency, VHF band. Radio waves in the shortwave band can be reflected or refracted from a layer of electrically charged atoms in the atmosphere called the ionosphere. Therefore, short waves directed at an angle into the sky can be reflected back to Earth at great distances, beyond the horizon. This is called skywave or "skip" radio propagation, propagation. Thus shortwave radio can be used for communication over very long distances, in contrast to radio waves of higher frequency, which travel in straight lines (line-of-sight propagation) and are generally limited by the visual horizon, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
AMES Type 80
The Air Ministry Experimental Station, AMES Type 80, sometimes known by its development rainbow code Green Garlic, was a powerful early-warning radar, early warning (EW) and ground-controlled interception (GCI) radar developed by the Telecommunications Research Establishment (TRE) and built by Decca Radar, Decca for the Royal Air Force (RAF). It could reliably detect a large fighter aircraft, fighter or small bomber at ranges over , and large, high-flying aircraft were seen out to the radar horizon. It was the primary military ground-based radar in the UK from the mid-1950s into the late 1960s, providing coverage over the entire British Isles. In the late 1940s, the RAF developed the ROTOR plan to provide radar coverage over the UK in a phased rollout. As part of Stage 2, a new EW radar with long range would be deployed starting in 1957. A TRE research project, Green Garlic, appeared to be able to fill this role years earlier. The first examples of the Type 80 were being install ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Duga Radar
''Duga'' (, ) was an over-the-horizon radar (OTH) system used in the Soviet Union as part of its early-warning radar network for missile defense. It operated from July 1976 to December 1989. Two operational ''duga'' radars were deployed, with one near Chernobyl and Liubech in the Ukrainian SSR, and the other in eastern Siberia. The ''duga'' system was extremely powerful, reaching over 10 MW, and emitted in the shortwave radio bands. It was given the nickname Russian Woodpecker by shortwave listeners for its emissions randomly appearing and sounding like sharp, repetitive tapping noises at a frequency of 10 Hz. The random frequency hops often disrupted legitimate broadcasts, amateur radio operations, oceanic, commercial, aviation communications, and utility transmissions, resulting in thousands of complaints from many countries worldwide. The signal became such a nuisance that some communications receivers began including "Woodpecker Blankers" in their circuit designs. The u ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
AN/CPS-1
The AN/CPS-1, also known as the Microwave Early Warning (MEW) radar, was a semi-mobile, S band, early-warning radar developed by the MIT Radiation Laboratory during World War II. It was one of the first projects attempted by the Lab and was intended to build equipment to transition from the British long-wave radar to the new microwave centimeter-band radar made possible by the cavity magnetron. The project was led by Luis Walter Alvarez. Deployed to the European Theater in 1944, the MEW proved to be an extremely effective radar against German V-1 flying bombs and V-2 rockets. After the war, the AN/CPS-1 was adopted for use by civil aviation becoming the first radar used to track aircraft on civil air routes in the United States. The designation "CPS" under the JETDS system means “Fixed, Radar, Search” electronic device. Background In 1940, Vannevar Bush, head of the National Defense Research Committee, established the "Microwave Committee" (section D-1) and the "Fire Contro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chain Home Low
Chain Home Low (CHL) was the name of a British early warning radar system operated by the RAF during World War II. The name refers to CHL's ability to detect aircraft flying at altitudes below the capabilities of the original Chain Home (CH) radars, where most CHL radars were co-located. CHL could reliably detect aircraft flying as low as . The official name was AMES Type 2, referring to the Air Ministry Experimental Station at Bawdsey Manor where it was developed, but this name was almost never used in practice. The system had originally been developed by the British Army's research group, also based at Bawdsey, as a system for detecting enemy shipping in the English Channel. It was built using the electronics being developed for the aircraft interception radar systems, which worked on the 1.5 m band. This high frequency (200 MHz), for the era, allowed it to use smaller antennas that could be swung back and forth to look for returns, in contrast to the enormous fixed ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ballistic Missile Early Warning System
The RCA 474L Ballistic Missile Early Warning System (BMEWS, 474L System, Project 474L) was a United States Air Force Cold War early warning radar, computer, and communications system, for ballistic missile detection. The network of twelve radars, which was constructed beginning in 1958 and became operational in 1961, was built to detect a mass ballistic missile attack launched on northern approaches or15 to 25 minutes' warning time also provided Project Space Track satellite data (e.g., about one-quarter of SPADATS observations). It was replaced by the Solid State Phased Array Radar System in 2001. Background The Ballistic Missile Early Warning System (BMEWS) was a radar system built by the United States (with the cooperation of Canada and Denmark on whose territory some of the radars were sited) during the Cold War to give early warning of a Soviet intercontinental ballistic missile (ICBM) nuclear strike, to allow time for US bombers to get off the ground and land-based U ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Airborne Early Warning And Control
An airborne early warning and control (AEW&C) system is an airborne radar early warning system designed to detect aircraft, ships, vehicles, missiles and other incoming projectiles at long ranges, as well as performing command and control of the battlespace in aerial warfare, aerial engagements by informing and directing friendly fighter aircraft, fighter and attack aircraft. AEW&C units are also used to carry out aerial surveillance airborne ground surveillance, over ground and maritime surveillance, maritime targets, and frequently perform battle management command and control (BMC2). When used at altitude, the radar system on AEW&C aircraft allows the operators to detect, track and prioritize targets and identify friendly aircraft from hostile ones in real-time and from much farther away than ground-based radars. Like ground-based radars, AEW&C systems can be detected and targeted by opposing forces, but due to aircraft mobility and extended sensor range, they are much less vul ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
RAF Fylingdales Radar
The Royal Air Force (RAF) is the air and space force of the United Kingdom, British Overseas Territories and Crown Dependencies. It was formed towards the end of the First World War on 1 April 1918, on the merger of 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 played History of the Royal Air Force, a significant role in Military history of the United Kingdom, British military history. In particular, during the Second World War, the RAF established Air supremacy, air superiority over Nazi Germany's Luftwaffe during the Battle of Britain, and led the Allied strategic bombing effort. The RAF's mission is to support the objectives of the British Ministry of Defence (United Kingdom), Ministry of Defence (MOD), which are to "provide the capabilities needed to ensure the security and defence of the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ionosphere
The ionosphere () is the ionized part of the upper atmosphere of Earth, from about to above sea level, a region that includes the thermosphere and parts of the mesosphere and exosphere. The ionosphere is ionized by solar radiation. It plays an important role in atmospheric electricity and forms the inner edge of the magnetosphere. It has practical importance because, among other functions, it influences radio propagation to distant places on Earth. Travel through this layer also impacts GPS signals, resulting in effects such as deflection in their path and delay in the arrival of the signal. History of discovery As early as 1839, the German mathematician and physicist Carl Friedrich Gauss postulated that an electrically conducting region of the atmosphere could account for observed variations of Earth's magnetic field. Sixty years later, Guglielmo Marconi received the first trans-Atlantic radio signal on December 12, 1901, in St. John's, Newfoundland (now in Canada) usin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Over-the-horizon Radar
Over-the-horizon radar (OTH), sometimes called beyond the horizon radar (BTH), is a type of radar system with the ability to detect targets at very long ranges, typically hundreds to thousands of kilometres, beyond the radar horizon, which is the distance limit for ordinary radar. Several OTH radar systems were deployed starting in the 1950s and 1960s as part of early-warning radar systems, but Airborne early warning and control, airborne early warning systems have generally replaced these. OTH radars have recently been making a comeback, as the need for accurate long-range tracking has become less important since the ending of the Cold War, and less-expensive ground-based radars are once again being considered for roles such as maritime reconnaissance and drug enforcement. Technology The frequency of radio waves used by most radars, in the form of microwaves, propagate in straight lines. This generally limits the detection range of radar systems to objects on their Radar horizo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Canada
Canada is a country in North America. Its Provinces and territories of Canada, ten provinces and three territories extend from the Atlantic Ocean to the Pacific Ocean and northward into the Arctic Ocean, making it the world's List of countries and dependencies by area, second-largest country by total area, with the List of countries by length of coastline, world's longest coastline. Its Canada–United States border, border with the United States is the world's longest international land border. The country is characterized by a wide range of both Temperature in Canada, meteorologic and Geography of Canada, geological regions. With Population of Canada, a population of over 41million people, it has widely varying population densities, with the majority residing in List of the largest population centres in Canada, urban areas and large areas of the country being sparsely populated. Canada's capital is Ottawa and List of census metropolitan areas and agglomerations in Canada, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
