A propagating field approach to modal decomposition and source localization

Matched-mode processing provides a promising alternative to matched-field processing for locating a source in an acoustic waveguide. The successful application of this method relies on the accurate modal decomposition (mode filtering) of the pressure data received on a vertical line array. Estimates of source range are constructed from the measured phases and wavenumbers of the (resolved) modes, whereas estimates of source depth are constructed from the corresponding mode amplitudes and mode shapes. The authors describe a decomposition method based on the parabolic equation propagation model for recovering all the modal information needed to localize an underwater source by the matched-mode processing approach. The effectiveness of this propagation-based decomposition/localization scheme is demonstrated using simulated hydrophone data that were generated for a narrowband acoustic source operating in a shallow-water environment