What tool is used for SONAR?

SONAR (Sound Navigation and Ranging) primarily uses sonar systems that include transducers, which emit sound waves and receive echoes. These systems can be categorized into active and passive sonar. Active sonar sends out sound pulses and listens for their return, while passive sonar detects sounds made by objects in the water without emitting sound waves. Common tools used in sonar applications include echo sounders, hydrophones, and sonar arrays.