Abstract: In long baseline positioning system, the error induced by uncertain sound speed is the most damaging factor affecting the positioning accuracy. A long baseline system positioning correction algorithm with uncertain sound speed is proposed by setting the acoustic signal to propagate between the target and different hydrophones at different sound speed. First, a multi-parameter optimization function is built to estimate the effective sound speed using the redundant information in the long baseline system. Then the particle swarm optimization algorithm is utilized to solve the optimization function, and the effective sound speeds between the target and each hydrophones are obtained. Finally, the target is positioned by the resulting effective sound speed. The simulation results show that the proposed algorithm can effectively improve the positioning accuracy of long baseline positioning system compared with the existing algorithms.

Key words: long baseline positioning system, particle swarm optimization, effective sound speed, sound speed correction