Motion compensation for SAS antenna without iterative method

The sonar is a technique used to observe the underwater scene over large distances. The active sonar is mainly used for imaging or for bathymetry. With the modern sonar both uses are now possible. To form a high resolution three dimensional image, an active side-scan sonar is used. To develop algorithms in order to obtain an image, we need experimental data. One of the difficulties in the analysis of the sonar data is the fact that we don´t know either the seabed or the accurate position of the sonar. The experimental side of studies can be complex. In this paper we describe the compensation of the movements. It exists differents methods to autofocus signals. Here, a first step the estimate micro navigation parameters is need. Motion is compensated in a second step, then a SAS algorithm can be use to obtain the image.