Abstract: Synthetic Aperture Sonar (SAS) is the high-resolution acoustic imaging technique which allows to improve the cross-range resolution. The main possibilities of SAS data gathering are the stripmap and spotlight modes. The stripmap system is only considered and analyzed in this paper. However, the results can be easily copied to the last one. In this specific mode, the sonar beam always points in the same direction (e.g. perpendicular to the direction of the travel) during imaging. The fundamental problem with the extraction of the echoes from the finite seafloor area appears in such a system. In order to deal with this inconvenience, we can take advantage of the well-known polar formatting, what is done in this paper. After that, the Omega-k algorithm is used to show some results of the numerical stripmap SAS system simulation. The outcomes confirm the possibility of the usage of the polar format processing to filter out the SAS signal from the undesirable contributions.