Single sensor source tracking and environmental inversion

A method is introduced for using a single underwater sensor and knowledge o f a shallow water environment to track a moving, multi-frequency, acoustic source. The motion of the source creates a synthetic aperture that is adapt ively matched against an acoustic propagation model in a manner similar to matched held processing. However, in this case, many more unknowns must sim ultaneously be determined. Results are presented for tracking using experim ental data subject to unknown source speed, heading, level, and initial pos ition. A new parallel adaptive method manages these simultaneous unknowns. Perturbations in the sound speed based on empirical orthogonal functions ar e used to extend the approach to operating when there also is uncertainty i n this parameter. The performance of the tracking process with hydrophone d ata for various signal-to-noise cases is considered. (C) 1999 Acoustical So ciety of America. [S0001-4966(99)01209-6].