Abstract：The paper introduced the system construction,positioning principle and control flow of secondary acoustic positioning system,analyzed in detail the error of GPS measuring system produced in the process of secondary acoustic positioning and 3-D correlation in the zenith coordinate system of antenna phase center,the error resulted from GPS system and transmitting/receiving transducer position,positioning flow and time-delay error and error existed in computation of acoustic velocity,implemented qualitative and quantitative study on their size and direction and gave the methods reducing and eliminating various errors and thus further improving positioning precision.
