Synthetic aperture sonar processing for the HUGIN AUV

The Norwegian Defence Research Establishment (FFI) and Kongsberg Maritime AS have an ongoing program to develop synthetic aperture sonar (SAS) technology for the HUGIN autonomous underwater vehicle (AUV). This includes the development of a high-resolution multi-aspect interferometric SAS, named SENSOTEK, which has been installed on HUGIN I. During this project, FFI has developed a full suite of software for postprocessing of SAS data, named "FOCUS Synthetic Aperture Sonar Signal Processing Toolbox". The toolbox includes integrated DPCA and INS navigation, beamforming both in time and wavenumber domain, autofocusing by map drift and contrast optimization, and seafloor height estimation by cross correlation techniques and interferometry.