Image reconstruction for synthetic aperture sonar (SAS) system with Vernier array technique

To overcome the blurring problem caused by displaced phase center (DPC) approximation, a modification of the standard range-Doppler (R-D) algorithm is proposed to process the Vernier array data based on the bistatic sonar model, and to reconstruct the target area from the data of the individual transmitter/receiver pair. If there are H receivers, H individual images are obtained. All the individual images are then coherently added to form the final high resolution SAS image. Simulation results by the DPC approximation processing, modified R-D algorithm and coherent addition are presented. They show that the image blurring caused by DPC approximation can be removed by using the modified R-D algorithm, both the range resolution and azimuth resolution can be obviously improved after coherent addition. The simulation results validate the feasibility and validity of the new method.