Moderate squint imaging algorithm for the multiple-hydrophone SAS with receiving hydrophone dependence

摘要

The existing imaging algorithms for the multiple-hydrophone synthetic aperture sonar (SAS) cannot obtain a good imaging result in the moderate squint case where the squint angle is from 10° to 20°, because they do not take the differential range curvature into account, and the existing methods of equivalent spatial sampling cannot work well. This study proposes an imaging algorithm for the moderate squint multiple-hydrophone SAS. First, the range history model of the moderate squint multiple-hydrophone SAS is established. Second, the signal of each hydrophone is processed separately with bistatic imaging algorithm to correct the differential range curvature. Third, the corrected signal of each hydrophone is shifted to the same range bin to compensate the relative range offset, and is added coherently together to remove the azimuth aliasing and to reconstruct the image without loss of resolution. Fourth, a new method of equivalent azimuth sampling is developed, and a PRF adjusted with squint angle is given. Finally, the validity of the proposed algorithm is tested by the simulation and real data.