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The history of radar (where radar stands for radio detection and ranging) started with experiments by Heinrich Hertz in the late 19th century that showed that radio waves were reflected by metallic objects. This possibility was suggested in James Clerk Maxwell 's seminal work on electromagnetism.
Radar is a system that uses radio waves to determine the distance (ranging), direction (azimuth and elevation angles), and radial velocity of objects relative to the site. It is a radiodetermination method [1] used to detect and track aircraft, ships, spacecraft, guided missiles, motor vehicles, map weather formations, and terrain.
Doppler effect. The emitted signal toward the car is reflected back with a variation of frequency that depends on the speed away/toward the radar (160 km/h). This is only a component of the real speed (170 km/h). The Doppler effect (or Doppler shift), named after Austrian physicist Christian Doppler who proposed it in 1842, is the difference ...
Christian Hülsmeyer. Christian Hülsmeyer (Huelsmeyer) (25 December 1881 – 31 January 1957) was a German inventor, physicist and entrepreneur. He is credited with the invention of radar, although his apparatus, called the "Telemobiloscope," could not directly measure distance to a target. The Telemobiloscope was, however, the first patented ...
After the United States entered World War I in 1917, Loomis volunteered for military service. He was commissioned as a captain, and rose to the rank of lieutenant colonel. He worked in ballistics at the Aberdeen Proving Ground in Maryland, where he invented the Aberdeen Chronograph, the first instrument to measure accurately the muzzle velocity of artillery shells, and portable enough to be ...
A radar detector is an electronic device used by motorists to detect if their speed is being monitored by police or law enforcement using a radar gun. Most radar detectors are used so the driver can reduce the car's speed before being ticketed for speeding. In general sense, only emitting technologies, like doppler RADAR, or LIDAR can be detected.
Radar in World War II greatly influenced many important aspects of the conflict. [1] This revolutionary new technology of radio-based detection and tracking was used by both the Allies and Axis powers in World War II, which had evolved independently in a number of nations during the mid 1930s. [2] At the outbreak of war in September 1939, both ...
Watson-Watt [a][5] was born in Brechin, Angus, Scotland, on 13 April 1892. He claimed to be a descendant of James Watt, the famous engineer and inventor of the practical steam engine, but no evidence of any family relationship has been found. [6] After attending Damacre Primary School and Brechin High School, [7] he was accepted at University ...