How Does a Sonobuoy Work?

A sonobuoy is a specialized piece of equipment used for sonar in particular situations. The name is derived by putting together the two words that describe it, sonar and buoy. Essentially, it is an information collection device that uses sonar and can float. It can be used in several industries, but is mainly utilized in military applications and oil and gas exploration. Most people will never directly use a sonobuoy, but many benefit from the core technology that can detect, triangulate, or track things in difficult to reach water environments.

Sonobuoys can easily be dropped or ejected from ships or airplanes over the body of water that needs to be explored. When they hit the water, an inflatable device keeps the top portion on the surface of the water. There, a radio transmitter is able to communicate with the station that deployed it. Below the water, stabilizing equipment and hydrophone sensors descend to a predetermined depth to collect information and take readings. The depth chosen depends on the type of data being gleaned, the overall depth of the water in that spot, and the weather conditions. Using sound waves, the information being gathered is relayed back to a sonar operator, satellite, or computer to be analyzed and stored.

The three types of sonobuoys are active, passive, and special purpose. The active varieties emit a ping. Sometimes the pings are programed to stop after a particular time period, but they can also be controlled in real time by an operator through radio waves. The sound wave from the ping travels out and away from the device, then bounces off of surrounding structures and returns, like an echo. This provides information about the contents of the water in which they are deployed. A passive sonobuoy does not emit any pings, but rather waits for sound energy to come to it from surrounding structures, ships, or animals. Special purpose options are used for data collection about the ocean salinity or temperatures, for search and rescue operations, or to act as a down-link for communication at sea.

If you would like to learn more about a Sonobuoy, click here.