What are Sonobuoys?

Aug. 25, 2024

The United States of America (USA) recently approved a USD 52.8 million government-to-government deal for the sale of Anti-Submarine Warfare (ASW) Sonobuoys that will be integrated with the Indian Navy’s Romeo helicopters.

About Sonobuoys:

  • They are small, expendable devices used in underwater acousticsand sonar systems to detect and analyze sound in the ocean, particularly for tracking submarines and other underwater objects.
  • It is a core technology for anti-submarine warfare.
    • It helps to track potentially hostile submarines operating in the open ocean and in coastal areas.
    • Information from these systems can help enable precision attacks with air-launched torpedoes.
  • They were first used during the Second World War to detect German U-boats.
  • Deployment:
    • Sonobuoys are deployed by dropping them into the ocean from aircraft or launching them from shipsor submarines.
    • They sink to a predetermined depth and begin listening for acoustic signals, helping pin-point potential submarine threats.
    • Multiple sonobuoys can be deployed in a pattern to determine the exact location of a target.
  • There are three types of sonobuoys:
    • Passive Sonobuoys quietly listen for and record sounds without emitting any signals. It uses a hydrophone to listen for sound energy from a target.
    • Active Sonobuoys emit a sound pulse and analyze the return signals (echoes) to detect and locate targets. It uses a transducer to send an acoustic signal.
    • Special Purpose buoys provide information about the environment, such as water temperature, ambient noise level, etc.
  • Components: A typical sonobuoy consists of a cylindrical or spherical buoyant housingsensors for detecting acoustic signals, a battery or power source, and a radio transmitter or other communication system to relay data to the host platform (e.g., aircraft or ship).
  • Other Applications: In addition to anti-submarine warfare, they are used for scientific research and environmental studies, including studying the behavior of whales and other marine creatures.