Sound navigation and ranging, a technique used at sea for
detecting and determining the position of underwater objects (e.g., submarines,
shoals of fish) and for finding the depth of water under s ship's keel. Sonar works on the principle
of echolocation: high-frequency sound
pulses are beamed from the ship and the direction of and time taken for
any returning echoes are measured to
give the direction and range of the reflecting objects.
|Locating fish with sonar