New motion error estimation method based on images correlation for multi-hydrophone SAS

A new method for estimating yaw and sway of a multi-hydrophone synthetic aperture sonar (SAS) using images correlation which is applicable to homogeneous scene was proposed. With this method, the multi-hydrophone SAS may travel at the maximum allowable speed as determined by the spatial sampling theorem. The images from adjacent two ping echoes were reconstructed firstly, and then they were transformed to polar coordinates for yaw estimation by images correlation. The sway was estimated after yaw compensation. In view of discrete data, a method for image transformation from Cartesian coordinates to polar coordinates was given. The method analyzed the resolution of image in polar coordinates and bounded the polar coordinates span according to the area of images from adjacent two ping echoes, so the computing load was reduced. Some simulation results show that the new algorithm estimates the yaw and sway effectively and the image quality is improved.