Frequency domain beamformer for a 3-D sediment volume imaging synthetic aperture sonar

A frequency domain beamforming approach is described for 3-D sediment volume imaging synthetic aperture sonars (SAS). The beamformer, designed for systems with receiver arrays oriented transverse to the vehicle, performs standard delay and sum processing for each ping in the across-track direction followed by multi-ping synthetic aperture processing of elevation planes in the along-track direction. The beamformer can be run repeatedly with varying along-track squint angles revealing aspect-dependent target features. The collection of elevation planes, independently computed by the frequency domain beamformer, can be processed simultaneously on multiple threads of execution, in order to take advantage of multi-CPU machines.