Design of high accuracy ultra short baseline underwater acoustic position system

The traditional position of ultra-short baseline (USBL) adopts single-frequency CW signal and phase difference to resolve. This method leaves the problem of phase difference measurement ambiguity. And its position accuracy cannot meet the requirement of engineering. Therefore, this system adopts the broadband signal as the responsive signal. This approach achieves position via measuring the time delay difference of the responsive signal reach different array elements. The position accuracy is influenced by the accuracy of measuring time delay. As a result, the system uses the method, estimate of correlation peak and correction of three-point interpolation, to improve the estimation accuracy of time delay. The hardware platform of the system exploits 3 DSP+FPGA as the core. It completes high-accuracy time measurement by the receive signals and resolves geodetic coordinate real-time. The motion trails will be displayed on the upper computer finally. This system has the features of high data processing ability, strong real-time control, good expand-ability and etc. It contents with the requirement of engineering and has practical significance for engineering application.