An acoustic positioning of underwater vehicles using synthetic long baseline navigation

Underwater navigation that relies solely on dead reckoning suffers from unbounded position error growth. In traditional positioning method, the cost and trouble of deploying, recovering, and assembly have become insuperable obstacle. Based on combination SLBL with an Argo float, a new positioning method of autonomous navigation is proposed in the paper. In order to improve the ranging accuracy, with the pattern time delay shift coding system, the second correlation method is given for time delay estimation in this paper. The superiority of the second cross-correlation method is that time delay could be estimated in a lower signal-to-noise ratio environment and in the complex multipath channels compared to the first cross-correlation method. At last, some field trial results show that the second correlation method could suppress the multipath interference in underwater channel efficiently, and that the position of moving vehicle is solved from point-to-point based on the estimation of bearing and ranging.