Lidar vs. Sonar — What's the Difference?

Lidar (, also LIDAR, or LiDAR; sometimes LADAR) is a method for determining ranges (variable distance) by targeting an object with a laser and measuring the time for the reflected light to return to the receiver. Lidar can also be used to make digital 3-D representations of areas on the earth's surface and ocean bottom, due to differences in laser return times, and by varying laser wavelengths.

Sonar (sound navigation and ranging) is a technique that uses sound propagation (usually underwater, as in submarine navigation) to navigate, 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.

An optical sensing technology used to determine the position, velocity, or other characteristics of distant objects by analysis of pulsed laser light reflected from their surfaces.

A system using transmitted and reflected underwater sound waves to detect and locate submerged objects or measure the distance to the floor of a body of water.

The equipment used in such detection. In both senses also called laser radar.

An apparatus, as one in a submarine, using sonar.

The optical analogue of radar, using intense pulses of laser light to measure the composition and structure of the atmosphere.

Echolocation.

A measuring system that detects and locates objects on the same principle as radar but uses light from a laser; a potential technology for detecting air turbulence that can affect aircraft

(nautical) echolocation

(nautical) A device that uses hydrophones (in the same manner as radar) to locate objects underwater.

A measuring instrument that sends out an acoustic pulse in water and measures distances in terms of the time for the echo of the pulse to return; sonar is an acronym for sound navigation ranging; asdic is an acronym for anti-submarine detection investigation committee