Precision Hybrid Inertial/Acoustic Navigation System for a Long‐Range Autonomous Underwater Vehicle

: The Canadian Department of National Defence has developed an autonomous underwater vehicle (AUV) capable of performing long-range missions in ice-covered waters. Autonomous operations in such an extreme environment, where a priori knowledge of the bathymetry is frequently limited, requires a navigation system that is precise, reliable, and repeatable. A hybrid navigation system has been developed that provides precise navigation by combining data from two different types of sensors—inertial and acoustic. This navigation system has been integrated into a large AUV, and for mission lengths of up to 200 km has demonstrated horizontal navigational accuracies of better than 0.05 percent of distance traveled. This paper describes the AUV and its mission, the specific navigation sensors selected, and how the overall navigation solution is mechanized. It also describes the behavior of the navigation system during field experiments and during a successful long-range under-ice mission in the High Arctic.