Target Localization in an Inhomogeneous Medium

摘要

A computer algorithm was developed to determine if an acoustic transmitter can be localized, based on estimates of local angles of arrival of acoustic signals incident upon a receive planar sonar array, knowledge of the deterministic effects of the ocean on sound propagation, and local sound-speed profiles of the ocean. The algorithm was designed to determine azimuthal and elevation/depression angles to the transmitter as well as computing the depth, range, cross range, and line-of-sight range separations between the transmitter and the receive array. The algorithm utilizes ray acoustics and model-based phase weights to determine the transmitter's location relative to the receive array's position. As written, the algorithm is capable of solving localization problems in which the transmitter and receiver are in the same gradient of the local sound-speed profile, provided that the range from transmitter to receiver is not so great that the acoustic signal passes through a turning point prior to reaching the receive array. The results indicate that the method proposed is viable for the class of problems for which it was designed, and accuracies on the order of 0.1 meters are obtained for line-of-sight ranges on the order of several kilometers.