Radar

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 used to detect and track aircraft, ships, spacecraft, guided missiles, motor vehicles, weather formations and terrain. The term RADAR was coined in 1940 by the United States Navy as an acronym for "radio detection and ranging".

Extends: Radar, [1940s neologisms](https://wikipedia.org.ai/1940s neologisms), [Aircraft instruments](https://wikipedia.org.ai/Aircraft instruments), [Air traffic control](https://wikipedia.org.ai/Air traffic control), Avionics