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Most of today's radar detectors detect signals across a variety of wavelength bands: usually X, K, and K a. In Europe the K u band is common as well. The past success of radar detectors was based on the fact that radio-wave beams can not be narrow-enough, so the detector usually senses stray and scattered radiation, giving the driver time to ...
Hedy Lamarr (/ ˈ h ɛ d i /; born Hedwig Eva Maria Kiesler; November 9, 1914 [a] – January 19, 2000) was an Austrian-born American actress and inventor. After a brief early film career in Czechoslovakia, including the controversial erotic romantic drama Ecstasy (1933), she fled from her first husband, Friedrich Mandl, and secretly moved to Paris.
Joan, Lady Curran (born Joan Elizabeth Strothers; 26 February 1916 – 10 February 1999) was a Welsh physicist who played important roles in the development of radar and the atomic bomb during the Second World War. She devised a method of releasing chaff, a radar countermeasure technique credited with reducing losses among Allied bomber crews.
As radar was being developed, astronomers considered its application in making observations of the Moon and other near-by extraterrestrial objects. In 1944, Zoltán Lajos Bay had this as a major objective as he developed a radar in Hungary. His radar telescope was taken away by the conquering Soviet army and had to be rebuilt, thus delaying the ...
Radar detectors are built around a superheterodyne receiver, which has a local oscillator that radiates slightly. It is therefore possible to build a radar-detector detector, which detects such emissions (usually the frequency of the radar type being detected, plus about 10 MHz for the intermediate frequency).
The AI Mk.IV radar was the first operational aircraft interception (AI) radar.It was used experimentally in April 1940, and entered widespread service in early 1941. These systems used a set of four receiver antennas that were arranged so they were most sensitive in different directions; two were sensitive above or below the aircraft, and the other two to the left and right.
The radar had a fairly crude display but was able to give the range and an approximate direction within an arc either side of the aircraft heading. Returns were lost in sea clutter once the aircraft was within about 1 mi (1.6 km) of the U-boat but usually by then, the aircraft was within visual range and the U-boat was well into a crash dive.
The FuG 227 Flensburg was a German passive radar receiver developed by Siemens & Halske and introduced into service in early 1944. It used wing and tail-mounted dipole antennae and was sensitive to the mid-VHF band frequencies of 170–220 MHz, subharmonics of the Monica radar's 300 MHz transmissions.