Textural analyses of multibeam sonar imagery from Stanton Banks, Northern Ireland continental shelf

The mapping of marine habitats mainly relies on acoustic techniques and there is a clear need for reliable classification methods supplementing the interpreter with as much quantitative information as possible. This article presents textural analyses of multibeam sonar imagery from Stanton Banks, on the continental shelf off Northern Ireland. TexAn, originally developed for the textural analysis of sidescan sonar imagery, was tested over an area of ∼72 km² surveyed in 2005 by the European MESH project. The multibeam imagery is affected by several artefacts, including strong uncorrected angular variations in some tracks, and the acquisition of some tracks with very different aspects. The results from unsupervised classification of the imagery, using K-Means, match well the interpretations that can be made using concurrent bathymetric data and visual observations acquired in a later cruise. Textural analyses successfully detect faint trawlmarks and distinguish between the different types of seafloor, including variations within sediments, rocky outcrops and gullied terrains.