Marine Dictionary & Glossary of Boating Terms

Radar

RADAR is an acronym for radio detection and ranging, coined by the U.S. Navy in 1940. It is the use of electromagnetic waves - specifically radio waves - to determine the range, altitude, direction, or speed of both moving and fixed objects.

The RADAR device broadcasts a specific, or range of frequencies and detects the returning wave of the same frequency, bounced off an object. Using digital signal processing these returning radio waves are used to plot distance, direction and speed of the object that caused the returning signal. Since most radio waves are able to pass through fog, clouds, rain, falling snow, and sleet, RADAR is used in marine and aeronautical settings over and above infared or UV light methods for distance object detection.