'Sonar' is an acronym: SOund NAvigation and Ranging — modeled after 'radar.' Nature did it first with dolphins.
A system for the detection of objects under water by emitting sound pulses and detecting or measuring their return after being reflected.
An acronym of 'SOund NAvigation and Ranging,' modeled directly after 'radar' and coined in the 1940s, though the underlying technology — using sound waves to detect objects underwater — had been developed since World War I. The component words have deep roots: 'sound' from Old French 'son,' from Latin 'sonus' (a noise, a sound), from PIE *swenh₂- (to sound, to resound); 'navigation' from Latin 'nāvigāre' (to sail, to travel by ship), a compound of 'nāvis' (ship), from PIE *néh₂us (boat), and 'agere' (to drive, to set in motion), from PIE *h₂eǵ- (to drive); 'ranging' from Old French 'rengier' (to arrange in rows). Sonar thus means literally 'finding
'Sonar' was modeled after 'radar' — substituting 'sound' for 'radio.' The technology itself predates the acronym: underwater sound detection was developed during World War I (initially called 'ASDIC' by the British — an acronym whose exact expansion remains debated and possibly deliberately obscured for secrecy). Dolphins, bats, and whales use natural sonar (echolocation) — the technology humans spent decades developing, nature perfected