Sæbø, Torstein O.; Synnes, Stig A. V.; Hansen, Roy E. (Norwegian Defence Research Establishment (FFI), P. O. Box 25, NO-2027 Kjeller, Norway)
Synthetic aperture sonar (SAS) interferometry can provide bathymetric maps of the seafloor with high resolution over large swaths. Traditional narrowband interferometry relies on advanced phase unwrapping techniques to resolve phase ambiguities. For wideband systems there are alternative techniques to estimate the absolute (or ambiguity-free) phase difference. We consider complex cross correlation, split-spectrum algorithm, and the multi-chromatic approach. In addition, we develop a weighted split-spectrum algorithm. We benchmark these techniques on simulated data and demonstrate the techniques on real data from the HISAS wideband interferometric SAS on a HUGIN autonomous underwater vehicle.