What are Sonobuoys?

About Sonobuoys:

• Sonobuoys are small, expendable devices used in underwater acoustics and 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 ships or 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 buoyanthousing, sensors 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.

Q1. What is a transducer?

A transducer is an electronic device that converts energy from one form to another. Common examples include microphones, loudspeakers, thermometers, position and pressure sensors, and antenna.

Source: During Rajnath Singh’s ongoing visit, US approves sale of anti-submarine warfare sonobuoys to India