Sonobuoy

A sonobuoy is a small expendable sonar buoy dropped from aircraft or ships for anti-submarine warfare or underwater acoustic research. The name is a portmanteau of sonar and buoy. Sonobuoys are typically around 13 cm (5 in) in diameter and 91 cm (3 ft) long. When floating on the water, sonobuoys have both a radio transmitter above the surface and hydrophone sensors underwater. Sonobuoys are mission-critical platforms for enhancing Undersea Domain Awareness (UDA), providing an effective means to detect, locate, and track submarines and other underwater threats. Playing a key role in anti-submarine warfare (ASW) and other naval operations, they support in maintaining naval security and in protecting naval carrier strike groups.