Underwater acoustic positioning in multipath environment using time-of-flight signal group and database matching.

One of the challenges in underwater acoustic positioning is the occurrence of missing measurements and large errors in multipath environments, such as shallow water and harbor areas. In this paper, we propose a new underwater positioning method for multipath environments by using direct wave arrival time groups and database matching. The proposed method accurately measures baseline length from the impulse response of the underwater channel by calculating time window groups that cover the propagation time from the sound source to each hydrophone in advance and then extracting only the impulse response around the propagation time of the direct waves when the sound source exists in a certain region of the measurement space. The performance of the proposed method was experimentally evaluated in a static environment. The results showed that the proposed method achieved an accuracy of 0.03 m and a precision of 0.02 m in a test tank. [ABSTRACT FROM AUTHOR]