Underwater Gliders Using the A-Star Algorithm for Station Keeping in Currents

Underwater glider (UG) is becoming a reliable tool for continuous data collection due to its low operating cost, long-term observation, and easy deployment and recovery. UGs are a promising option for virtual moorings, because traditional moorings are expensive and cannot be easily transfered to other locations once installed. However, it is difficult for the UG to function like a real mooring and keep a small error distance between the surfacing locations and the surface target location in ocean currents. With the application of Hybrid Coordinate Ocean Model in ocean current prediction, the A-star algorithm is introduce in this study to to pick out the optimal azimuth as much as possible in currents. A sea trial was perfromed with the Petrel-II UGs developed by Tianjin University of China, which were deployed as virtual moorings for the observation of mesoscale eddies. According to the experimental results, it is effective and meaningful for UGs to adopt the A-star algorithm for station keeping in currents.