Quality assessment of synthetic aperture sonar images based on a single ping reference

Abstract

The formation of high resolution Synthetic Aperture Sonar (SAS) images requires precise position information of sensors over the whole synthetic aperture in order to coherently combine the reverberated signals. Due to an insufficient accuracy of the on-board navigation system additional means are necessitated. The state-of-the-art approach is to exploit the correlation structure of received echoes of overlapping phase centers between succeeding pings. This is well-known as the Displaced Phase Center Antenna (DPCA) or Redundant Phase Center (RPC) algorithm. We propose to use a quality metric to recursively assess the reconstructed images against a single ping reference image. This approach obtains a focused image with the maximum resolution by automatically selecting the maximum number of consecutive pings for which unwanted motion has completely been compensated.