Underwater sensors localization with matched multipath time delay in the deep ocean

Underwater sensors will diverge from the initial position because of the ocean current when the underwater sensors are deployed in the deep ocean. Assuming that the xy-plane coincides with the sea surface, a local Cartesian x-y coordinates system is set up in such a way that, when the sensors and sources are projected onto the local xy-plane, its origin coincides with the initial point of the sensors and the x-axis is parallel with east direction and positive y-axis is parallel with north direction. The depth of sensors can be obtained from press transducers, and the accurate position of the sources can be obtained from the GPS receiver attached to the ship and depths of the sources are preset. When the minimum time arrivals are snapped to a certain name, multipath time delay arrivals relative to the minimum time arrivals can be extracted from the measured signal and results of standard ray approach. The horizontal distance between the sensors and the sources can be estimated by matched time delays measured with ones calculated by BELLHOP model. Then the position of underwater sensors can be estimated by three points distance intersection method. Simulations and experiments are performed to demonstrate the feasibility of the method in the deep ocean. With the proposed method, the position of the underwater sensors can be localized in the deep ocean successfully.