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 NW 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 using K-Means match well concurrent bathymetric data and later (2006) visual observations. Textural analyses successfully detect faint trawlmarks and distinguish the different types of seafloor, including variations within sediments, rocky outcrops and gullied terrains.