An under water navigation supporting system for a 2000 m-deep oceanographic submersible ordered by JAMSTEC is described with special emphasis on its acoustic navigation system. The main function of the acoustic navigation system is to locate the mother ship relative to bottom-moored transponders and to locate the submersible relative to the transponders and/or the mother ship. An acoustic navigation technique is used for positioning. The system contains a long base line (LBL), a short base line (SBL), and a super short base line (SSBL) receiver. An advanced technique is applied to the SSBL acoustic positioning receiver : preformed beam technique with 16-element planar hydrophone array. Kalman filter is used for tracking and transponder calibration.
