How Useful Is Bathymetric Information in the Classification of High Frequency Sonar Surveys?

In a number of sonar studies, bathymetric information is used to correct and visualise amplitude data. This work proposes a method which combines amplitude features (describing backscattering strength and sonar texture) with bathymetric features (indicating seafloor variability) for sonar classification. Features are selected per window (of user defined size) and areas around grab samples in a survey are used for training. The importance of different features is investigated in this study, and highlighted by feature selection algorithms as well as by scatter plots exploring the training areas. Classification rates are significantly improved when both amplitude and bathymetry features are used. The method is applied to a sidescan bathymetric sonar dataset taken in Hopvågen bay-Norway.