Mid-water localization for Autonomous Underwater Vehicles

Abstract :

Survey class Autonomous Underwater Vehicles typically rely on Doppler Velocity Logs (DVL) for precise navigation near the seafloor. In deep-water, the seafloor depth is generally greater than the DVL bottomlock range. In this case, localizing between the surface, where GPS is available, and the seafloor presents a localization problem since both GPS and DVL are unavailable in the mid-water column. This research explores a solution to navigation in the mid-water column that exploits the stability of the water current field in space over the minutes scale. With repeated measurements of these currents with the Acoustic Doppler Current Profiler (ADCP) mode of the DVL during vertical descent, along with sensor fusion of other sensors, position error growth is constrained. This presentation briefly outlines present methods of localization, and how the addition of the ADCP-aided method allows novel capabilities, including application to the Europa Explorer project.