Definition
An electronic detection and ranging system that transmits sound waves through water and measures the time and direction of their returning echoes to locate and determine the distance of underwater objects.
Plain English
A system that sends out sound pulses underwater and listens for the echoes bouncing back, using the timing of those echoes to figure out where things are and how far away.
Context Anchor
Seen in search and rescue, naval aviation, and discussions of equipment used to find objects below the surface of water.
Derivation
An acronym formed from SOund Navigation And Ranging, built on the same naming pattern as radar (RAdio Detection And Ranging). Knowing this helps you remember that sonar is the underwater sound version of radar.
Why Pilots Care
Maritime pilots use sonar data to locate targets or debris that cannot be seen from the surface.
Intuition Check
Sonar is not radar. Radar uses radio waves; sonar uses sound waves, usually in water.
Example Sentence 1
The patrol aircraft dropped a pattern of sonobuoys, each containing a small sonar unit, to listen for the submarine.
Example Sentence 2
Sonar contact allowed the search team to pinpoint the submerged wreckage quickly.