Reconstructing seafloor bathymetry with a multichannel broadband InSAS using Belief Propagation

Synthetic Aperture Sonar (SAS) provides high resolution imagery with range independent resolution. However, imagery has been limited to two-dimensions, showing acoustic reflectivity for a given scene. To further enhance the usefulness of a SAS system this needs to be combined with a topographical height map of the same scene. This paper presents a novel technique to obtain the third-dimension by first remapping on to a set of common ground-planes, with the most likely surface through this volume found using Belief Propagation. This technique allows any a priori information to be incorporated and thus provides a maximum a posteriori (MAP) estimate of the seafloor height. Results are presented from a rough seafloor simulator with height reconstructions using this technique.