What is backscatter in the context of sonar?

Backscatter in the context of sonar refers specifically to the amount of energy that is reflected back to the sensor after being transmitted into the water column and interacting with the seabed or objects underwater. This phenomenon occurs when sound waves emitted by the sonar system encounter surfaces, which cause a portion of the sound energy to bounce back towards the sonar unit.

The strength and characteristics of the backscatter can provide valuable information about the type of materials on the seabed, such as sediment type, roughness, and even biological features. Different materials reflect sound waves differently, and analyzing the backscatter can assist hydrographic surveyors in creating accurate maps of the underwater terrain.

Understanding backscatter is crucial for interpreting sonar data effectively, allowing surveyors to differentiate between various seabed types and make informed decisions based on that information.