The calibration of the USBL transducer array for Long-range precision underwater positioning

This paper addresses a problem of estimating the additional phase shift between the transducers of the USBL array. The additional phase directly affects phase shift measurements due to the manufacturing technology of the transducer array, especially for the Long-range positioning system. Employing a least-squares method, the additional phase shift is considered to be determined experimentally by rotating the USBL array in an acoustic test tank. The results of the trials show that the proposed method can effectively measure the additional phase shift, and the positioning system can achieve with good accuracy after the calibration.