Baseline Estimation for Repeat-Pass Interferometric Synthetic Aperture Sonar

Abstract:
Synthetic aperture sonar has the potential to create extremely detailed maps of seafloor topography when repeated passes are flown at different altitudes to create a long interferometric baseline. However, navigation uncertainty typically limits the accuracy of the baseline measurement which is required to convert interferometric phase to seafloor depth. We present a data-driven baseline estimator and experimental results for the case where repeated passes are flown with an interferometric sonar consisting of two vertically displaced arrays. It is shown that co-registration of repeat-pass imagery and bathymetry alleviates the need to post-process data from a high grade inertial navigation system.