Multipath reduction for bathymetry using adaptive beamforming

Abstract

In this paper we consider adaptive beamforming techniques to suppress the dominant multipath for a multielement interferometric synthetic aperture sonar. We use a broadband variant of the minimum variance (MV) beamformer and apply it to reconstruct bathymetry using data from the KiwiSAS-4 sonar. This has three vertically displaced hydrophone arrays. The MV beamformer is used to estimate the angle of arrival of the backscattered echo from the sea floor, and from that the height of the sea floor. The conventional delay-and-sum (DAS) beamformer is used for comparison.