Compact Long-Range Underwater Velocity Sensor

Undersea Gliders and other high-persistence UUV’s face a significant challenge in meeting the low power consumption requirements for missions covering many months while at the same time suffering from reduced navigational accuracy. Most UUV payload systems require high navigational accuracy for target localization. This in turn requires accurate knowledge of ground speed. Typically, this is achieved by a GPS fix at the surface to initialize the navigation solution. Once the vehicle dives from the surface, it is dependent upon the inertial sensors and velocity log to maintain navigational accuracy. Existing velocity log devices suffer from several shortcomings: Large size and weight High cost Large power consumption Robustness to changes in ocean environment A three prong approach is proposed for this work: 1) Automatic tuning of the DVL corrections for depth, temperature, salinity and bottom type 2) Model based speed observer for estimating speed through the water 3) GPS/ACOMMS in two gliders (UUV’s) for estimating ground speed VCT will head the proposed team utilizing two separate universities and a private company to carry out the research in each approach.