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::Radar

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Radar::signal    Radar::antenna    Range::systems    Target::which    Radio::title    Aircraft::signals

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Radar is an object-detection system that uses radio waves to determine the range, angle, or velocity of objects. It can be used to detect aircraft, ships, spacecraft, guided missiles, motor vehicles, weather formations, and terrain. A radar transmits radio waves or microwaves that reflect from any object in their path. A receive radar, which is typically the same system as the transmit radar, receives and processes these reflected waves to determine properties of the object(s).

Radar was secretly developed by several nations in the period before and during World War II. The term RADAR was coined in 1940 by the United States Navy as an acronym for RAdio Detection And Ranging.<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref><ref>McGraw-Hill dictionary of scientific and technical terms / Daniel N. Lapedes, editor in chief. Lapedes, Daniel N. New York ; Montreal : McGraw-Hill, 1976. [xv], 1634, A26 p.</ref> The term radar has since entered English and other languages as a common noun, losing all capitalization.

The modern uses of radar are highly diverse, including air and terrestrial traffic control, radar astronomy, air-defense systems, antimissile systems; marine radars to locate landmarks and other ships; aircraft anticollision systems; ocean surveillance systems, outer space surveillance and rendezvous systems; meteorological precipitation monitoring; altimetry and flight control systems; guided missile target locating systems; and ground-penetrating radar for geological observations. High tech radar systems are associated with digital signal processing and are capable of extracting useful information from very high noise levels.

Other systems similar to radar make use of other parts of the electromagnetic spectrum. One example is "lidar", which uses ultraviolet, visible, or near infrared light from lasers rather than radio waves.


Radar sections
Intro   History   Applications  Principles  Radar signal processing  Engineering  See also  Notes and references    Bibliography   External links  

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