Building qualitative elevation maps from side scan sonar data for autonomous underwater navigation

Abstract data. Some previous work in this arcs hns bccn donc by Cuschieri Deriving a terrain model from sensor data is an important task for the autonomous navigation of a mobile robot. This paper describes an approach for autonomous underwater vehicles using a side scan sonar system. First. some general aspects of the type of data and filtering techniques to improve it are discussed. We then proceed to derive an estimated bottom contour, using a geomemc reflection model and information about shadows and highlights. Sevcral techniques of surface reconstruction and their limitations are presented. We also describe a method of feature exrraction which is important for future data matching/fusion procedures. and fleberr [4] and Sfeworf [lo]. Rigaud and.%force dcvclopcd in [9] a mcthod of acoustic data accumulition/fusion in ordcr to determine the absolutc location of an ROV. Currently we use data obtaincd by a sidc scan sonar sys tcm. Th