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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 * Beechcraft Bonanza#QU-22 Pave Eagle, 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. * OV-10 Bronco, 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 spec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wavelength
In physics, the wavelength is the spatial period of a periodic wave—the distance over which the wave's shape repeats. It is the distance between consecutive corresponding points of the same phase on the wave, such as two adjacent crests, troughs, or zero crossings, and is a characteristic of both traveling waves and standing waves, as well as other spatial wave patterns. The inverse of the wavelength is called the spatial frequency. Wavelength is commonly designated by the Greek letter ''lambda'' (λ). The term ''wavelength'' is also sometimes applied to modulated waves, and to the sinusoidal envelopes of modulated waves or waves formed by interference of several sinusoids. Assuming a sinusoidal wave moving at a fixed wave speed, wavelength is inversely proportional to frequency of the wave: waves with higher frequencies have shorter wavelengths, and lower frequencies have longer wavelengths. Wavelength depends on the medium (for example, vacuum, air, or water) that a wav ... [...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 Chernihiv in the Ukrainian SSR (present-day Ukraine), and the other in eastern Siberia (present-day Russia). The ''duga'' system was extremely powerful, reaching over 10 MW, and broadcast 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 by many countries worldwide. The signal became such a nuisance that some communications receivers began including "Woodpecker ... [...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. This project, led by Luis Walter Alvarez, became the world's first microwave phased-array antenna. 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. Background In 1940, Vannevar Bush, head of the National Defense Research Committee, established the "Microwave Committee" (section D-1) and the "Fire Control" division (D-2) to develop a more advanced ... [...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 Airborne 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 anten ... [...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). 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 US ICBMs to be launched, to reduce the chances that a preemptive str ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Airborne Early Warning And Control
Airborne or Airborn may refer to: Arts, entertainment, and media Films * ''Airborne'' (1962 film), a 1962 American film directed by James Landis * ''Airborne'' (1993 film), a comedy–drama film * ''Airborne'' (1998 film), an action film starring Steve Guttenberg * ''Airborne'' (2012 film), a horror film Games * ''Airborne!'', a 1985 computer game by Silicon Beach Software * ''Airborne Ranger'', a 1987 computer game by Microprose * '' Asphalt 8: Airborne'', a 2013 video game * '' Medal of Honor: Airborne'', a 2007 video game Literature * ''Airborn'' (novel), a 2004 young adult novel by Kenneth Oppel *''Airborn'' (''Hijos del aire''), a poetry collection by Octavio Paz, English translation Charles Tomlinson 1981 Music Groups * Airbourne (band), an Australian hard rock band * The Airborne Toxic Event, an indie rock band Albums * ''Airborn'' (album) * ''Airborne'' (Curved Air album), 1976 * ''Airborne'' (Don Felder album) * ''Airborne'' (The Flying Burrito Brothers albu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
RAF Fylingdales Radar
The Royal Air Force (RAF) is the United Kingdom's Air force, air and space force. It was formed towards the end of the World War I, First World War on 1 April 1918, becoming the first independent air force in the world, by regrouping the Royal Flying Corps (RFC) and the Royal Naval Air Service (RNAS). Following the Allies of World War I, 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 taken History of the Royal Air Force, a significant role in Military history of the United Kingdom, British military history. In particular, it played a large part in the Second World War where it fought its most famous campaign, the Battle of Britain. 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 United Kingdom and overseas territor ... [...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. 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) using a kite-supported antenna for reception. The transmitting station in Poldhu, Cornwall, used a spark-gap transmitter to produce a signal with a freq ... [...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 these have generally been replaced by airborne early warning systems. OTH radars have recently been making a comeback, as the need for accurate long-range tracking becomes less important with 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, travel in straight lines. This generally limits the detection range of radar systems to objects on their horizon (generally referred to as "line of sig ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Canada
Canada is a country in North America. Its ten provinces and three territories extend from the Atlantic Ocean to the Pacific Ocean and northward into the Arctic Ocean, covering over , making it the world's second-largest country by total area. Its southern and western border with the United States, stretching , is the world's longest binational land border. Canada's capital is Ottawa, and its three largest metropolitan areas are Toronto, Montreal, and Vancouver. Indigenous peoples have continuously inhabited what is now Canada for thousands of years. Beginning in the 16th century, British and French expeditions explored and later settled along the Atlantic coast. As a consequence of various armed conflicts, France ceded nearly all of its colonies in North America in 1763. In 1867, with the union of three British North American colonies through Confederation, Canada was formed as a federal dominion of four provinces. This began an accretion of provinces an ... [...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 pul ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
