Image enhancement by motion compensation of a moving array for underwater target detection

Abstract

Recently synthetic aperture sonar is widely used for precise seafloor exploration or underwater target detection. In order to acquire clearer sonar images, accurate measurement of the platform motion is absolutely required. Various approach has been studied for the motion estimation and compensation for sonar image generation. A tank test for underwater target detection has been done using an array mounted on a vertical bar attached on a horizontally moving platform. The array was vibrating when moving and the motion was measured using asynchronous navigational sensors installed just beside the array. In this study images constructed by synthetic aperture processing before and after motion compensation are compared. Across track array movement as well as translational motion with tilt angle was applied during the experiment. Additional numerical analysis of target detection with various motion parameters are performed. The effect of the motion estimation error and the installation offset are also analyzed.