Synthetic Aperture Sonar Tomography: A Preliminary Study

Synthetic aperture sonar (SAS) interferometry can provide bathymetric maps of the seafloor with high resolution over large swaths. Traditional single-pass interferometry using two vertically separated receiver arrays is limited to only estimate a single off-nadir angle per range resolution cell. This means that only the depth of the effective phase center is measured in layover regions. In synthetic aperture radar (SAR) it has been suggested to use multibaseline data and tomographic imaging to resolve depth ambiguities in layover regions. In this paper, we will describe and test a tomographic imaging algorithm on simulated SAS data. We will also evaluate the feasibility for using the tomography technique on real data from the HISAS wideband interferometric SAS on a HUGIN autonomous underwater vehicle.