Sonar
TECHNIQUE THAT USES SOUND PROPAGATION
SONAR; ASDIC; Asdic; Active sonar; Lfas; Passive sonar; Upward looking sonar; Sonars; Acoustic radar; Sound navigation and ranging; Active acoustics; Low Frequency Active Sonar; Passive Sonar; Sonar Projector; Anti-Submarine Detection and Identification Commission; So.n.a.r.; Variable depth sonar; Sonar system; Low frequency active sonar; Ping (sound); Sonar projector; History of sonar; Dipping sonar; Surface duct; Limpet mine imaging sonar; LIMIS; Dunking sonar; Imaging sonar; Military applications of sonar; Sonic navigation and ranging; Fisheries sonar; Net location sonar; Net sonar
Sonar (sound navigation and ranging) is a technique that uses sound propagation (usually underwater, as in submarine navigation) to navigate, measure distances (ranging), communicate with or detect objects on or under the surface of the water, such as other vessels. Two types of technology share the name "sonar": passive sonar is essentially listening for the sound made by vessels; active sonar is emitting pulses of sounds and listening for echoes.