Background

MBES backscatter refers to the reflection or scattering of sound waves back to their source, as measured by a Multibeam Echosounder System (MBES). This data describes the portion of sound waves emitted by the echosounder that are reflected back from the seafloor or other underwater objects. The intensity and nature of MBES backscatter are influenced by the properties of the reflecting surface, such as its roughness, texture, and material composition, as well as the frequency and incident angle of the sound waves.

MBES backscatter is extensively used in marine surveying to map the seafloor and detect objects. It helps determine the composition and type of seafloor materials, such as sand, mud, and rock, and assists in identifying habitats and studying marine ecosystems. By analysing the strength of the backscatter signal, researchers can infer the properties of the reflecting surface and create detailed images and maps of the seafloor. Thus, MBES backscatter is crucial for mapping, surveying, and understanding the seafloor and underwater environments.

Despite efforts to unify MBES backscatter acquisition, processing and delivery, there are no globally recognised standards to adhere to. Currently, there are many organisations using various acquisition systems and parameters, processing strategies and data formats that limit the usability and interoperability of MBES backscatter data, particularly when attempting to combine datasets to map large regions of the seabed. Therefore, defining MBES backscatter specifications for L3 products (Table 1) is an important step towards standardisation and data optimisation.

Table 1. AusSeabed data level L3 definition.