radar
1. Acronym for radio detection and ranging.
1. A radio detection system that transmits short bursts (pulses) of rf energy and detects their echoes from objects (targets) such as aircraft or ships.
Note: The round-trip propagation time for the echo return may be used to determine the target’s range (distance from the radar’s antenna). If the transmitting antenna has a narrow beam (the usual case), the azimuth or elevation of the target may also be determined. Synonym primary radar.
2. A radio detection device that provides information on range, azimuth, and/or elevation of objects. [JP 1-02]
3. A radiodetermination system based on the comparison of reference signals with radio signals reflected, or retransmitted, from the position to be determined. [NTIA] [RR]