Optimising collection geometry for long-range synthetic aperture sonar interferometry

Abstract

Interferometric synthetic aperture sonar (SAS) is a technique to image and map theseabed in very high resolution. For large area coverage rate systems with hundreds ofmetres swath width, the achievable performance varies significantly over the swath. Theperformance is a function of system, collection geometry, and seabed type. A model issuggested to optimise the collection geometry for maximising area coverage rate givencertain optimisation criteria, such as observation geometry, signal‐to‐noise ratio, depthmeasurement accuracy, and coverage within swath. The model is fitted to measurements(or calibrated) through a simple procedure. Specifically, the effect of vehicle altitudeduring the interferometric SAS data collection is studied. A novel model on data collectedby a HUGIN Superior autonomous underwater vehicle carrying a HISAS 1032 Dual Rxinterferometric SAS is demonstrated. The authors show that optimising the collectiongeometry, and in this case specifically the vehicle altitude, significantly improves theoverall performance.