How Does Radar Work?
Radar is a system for determining an object’s location, and how far away it is, even though you can’t see it. To detect airplanes and other objects, a revolving radar antenna sends out beams of radio waves as it sweeps around.
When the waves hit an object, they bounce back to the antenna. The radar measures the time that the waves took traveling out to the object and back again, and automatically figures how far away the object is.
Instantly a bright mark appears on the radar screen showing the distance to the object and the direction in which it is located. 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. 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.