Hybrid Localization Based on Time of Arrival and Phase Difference of Arrival Fusion

To locate the underwater target moving in a large area with a short trajectory, it is necessary to guarantee the positioning accuracy across the whole area. In the paper, a hybrid distributed underwater acoustic positioning system is employed. A positioning method based on time of arrival (TOA) and phase difference of arrival (PDOA) fusion is proposed. According to the statistical characteristics of the measured parameters, an optimization model is constructed based on the maximum likelihood (ML) criterion. With depth of the target estimated independently, the highly nonlinear optimization problem is solved by differential evolution (DE) algorithm. Complementary observation information is fully fused in the proposed method. Simulation results demonstrate the accuracy improvement of the proposed method throughout the observation area. Lake trial results further verify the effectiveness of the proposed method.