Simultaneous estimation of sea level and underwater vehicle location

This paper proposes an UKF (unscented Kalman filter) method for localization and sea level estimation of an underwater vehicle. The method uses the information of both the seabed geometry and depth of the vehicle from sea surface. Since the sea level fluctuates with time due to tide, wave, and precipitation, depth of the vehicle and range data to seabed sometimes mislead the location estimation. If sea level is estimated simultaneously, the ambiguity of location estimation will be reduced and the depth and range data become sufficient for localization of an underwater vehicle.