Underwater precise navigation using multiple sensor fusion

This paper introduces the implementation of a precise underwater navigation solution using multi-sensor fusion technique, which is based on USBL, DGPS, DVL and AHRS measurements. To realize the accurate, precise and frequent update rate underwater navigation solution, three strategies are chosen. The first one is the heading angle calibration to enhance the performance of standalone dead-reckoning algorithm. The second one is introduction of effective outlier rejection algorithm. The third one is that absolute position is fused timely to prevent error accumulation of dead-reckoning, where the absolute position can be acquired from USBL or DGPS measurements considering predefined finite state machine. The performance of the developed algorithm is verified with experimental data of UUV(Unmanned underwater vehicle) at Sea with various operation scenario.