(n)an electronic signal that has been reflected back to the radar antenna; contains information about the location and distance of the reflecting object
n. [ acronym from RAdio Detection And Ranging. ] 1. An electronic device designed to detect objects at a distance, and determine their distance from the device, by transmitting a pulse of radio waves and measuring the time required for the echo of the pulse to return to the emitting device; as, the radar showed a plane approaching rapidly. For more information of radar, see the article What is Radar?. [ acronym ] [ PJC ]
2. The method of detecting objects, finding their distance, or determining their speed, by use of a radar{ 1 } device; as, modern radar can detect objects as small as raindrops. [ PJC ]