Research of ultrashort baseline positioning method based on depth information

In order to propose a efficient, accurate and structure-simplified positioning system, the positioning method based on depth information was studied upon the foundation of the research on existing traditional ultrashort baseline(USBL) positioning system (method based on range). According to the formulas derivation, the positioning error of the depth method and the range method were compared. The numerical simulation analysis of the positioning error was carried out, under the combination of positioning error and Cramer-Rao lower bound(CRLB) theory of the delay estimation and the phase estimation. The results show that, in the case of long range positioning, the positioning accuracy based on depth information is higher than that of the range method, especially at high signal-to-noise ratio(SNR). In addition, the depth-based system also has the advantages of simple structure and fast positioning because the signal round-trip time is unnecessary to be measured.