An Improved Navigation Positioning Method for Underwater Moving Target at Long Range

Two conventional positioning methods for an underwater moving target, i.e. ship-borne hydrophone ar-ray-acoustic beacon tracking positioning method and ship-towed hydrophone array-acoustic beacon tracking positioning method, are of low tracking positioning accuracy, and of difficulty in implementation and equipment maintenance. So we presented an integrated guidance technology by equipping underwater target with optical fibre gyro and adopting dif-ferential global positioning system(DGPS) to measure and record in real time the attitude, velocity and position coordi-nates of an underwater moving target. The position coordinate data of the target are converted to synchronous underwa-ter acoustic multi-frequency and multi-pulse time-delay encoded signal for transmission, and the encoded signal is measured by ship-towed hydrophones and real-timely resolved by ship-borne base station, thus the measuring and con-trol ship can be guided to accomplish the tasks of tracking, positioning, and monitoring an underwater target at long range in real time. The sea trial result demonstrates the effectiveness of the proposed positioning technology.