Results of synthetic aperture sonar experiments

Results are presented from synthetic aperture sonar (SAS) experiments with three different test systems: one oriented toward mine detection; one toward buried UXO detection; and one toward buried cable detection. The first two systems share hydrophone arrays of 32-10-cm long elements. Results are presented that demonstrate key features of SAS images: azimuth resolution independent of range, grating lobe suppression by spatial sampling, synthetic filling of sparse array, and seafloor elevation from interferometric SAS. Results demonstrate resolutions of 10 to 20 cm at ranges up to 1000 m. Interferometric results compare SAS bathymetry and multi-beam echo sounder bathymetry.