A robust multiple-receiver Range-Doppler algorithm for synthetic aperture sonar imagery

Synthetic aperture techniques have been of interest to the sonar imaging community of the ocean floor, but suffer from the problem of slow mapping rate. Mapping rate is defined as the product of the swath width and sonar platform velocity, so it can be increased by widening swath or increasing platform velocity. However, wide swath and high platform velocity may cause range and azimuth ambiguities respectively. In many papers, multiple-receiver technique has been adopted to remove these ambiguities, but the image distortion caused by the stop-and-hop approximation (the platform transmits a signal, receives the echoes from targets, and then jumps to the next azimuth sampling location) is ignored or underestimated. For multiple-receiver synthetic aperture imaging with wide swath and high platform velocity, the error introduced by the stop-and-hop approximation must be corrected furthest. In this paper, a robust multiple-receiver Range-Doppler algorithm is proposed to process return data without the stop-and-hop approximation, and the simulation results show the validity of this method.