Document Library

The methods of bottom classification implemented in the BioSonics VBT Seabed Classifier are discussed in this paper. The objective is to help users to understand the physical principles of bottom classification methods implemented in the VBT software, using a simple intuitive approach without complex mathematics.

The information about bottom type, bottom sediments and aquatic plants is encoded in the echo signal. The signal can be stored and acquired simultaneously with GPS data. The echo signal can be decoded and information about the bottom can be projected onto a digital chart. In order to verify the results, either physical sampling of the bottom should occur or observation by divers or underwater camera should be recorded as acoustic data are acquired. Once verified, the results are saved so that unknown bottom types may be compared with this known and verified data set. The echo signal parameters depend on the type of bottom (in particular its hardness and roughness), but they also depend on the equipment parameters (i.e. frequency, transducer’s beamwidth and others). Therefore, the verified results will be valid only for the specific acoustic system that was used for verification.