Results of a three-row synthetic aperture sonar for multipath rejection

Synthetic aperture sonar (SAS) is an emerging technology for seafloor imaging, which has an appealing property of range- and frequency-independent spatial processing resolution. However, for a low-frequency SAS system operated in shallow water environments, there are often strong sea surface and bottom reflected multipath components that interfere with the desired echo signals. Previously a steered robust Capon beamforming method (SRCB) suitable for wideband SAS signals is developed to mitigate the effect of those interferences with a small vertically-displaced hydrophone array. In this paper, we apply this approach to experimental data of a prototype SAS imaging system. The results verify the performance improvements on output image quality over conventional processing in terms of both ghost target removal and contrast enhancement.