Motion compensation method based on image and receiving-data for multi-hydrophone SAS

The multi-hydrophone synthetic aperture sonar (SAS) may increase mapping rate, and sway and yaw are the key factors which results in image blurring. Based on the receiving-data-based motion compensation method for a collocated SAS, a new motion compensation method for a multi-hydrophone SAS was proposed which allowed the multi-hydrophone SAS to travel at the maximum allowable speed as determined by the spatial sampling theorem. With this method, the yaw was estimated by the image from each ping echo firstly, and then the sway was estimated by cross-correlating two adjacent ping echoes. A method for estimating time delay accurately with minor computing load was given. Simulation results using the proposed algorithm show that the proposed algorithm estimates the sway and yaw effectively and the image quality is improved.