Matched field processing: source localization in waveguides

Matched field processing (MFP), a generalized beamforming method which uses the complexity of an acoustic file in the ocean to localize sources in range, depth, and azimuth and to estimate parameters of the waveguide itself, is discussed. MFP exploits the coherence of the modal/multipath structure of the signals by using the full-field Green´s function for the signal propagation. It is especially effective at low frequencies where the ocean supports very coherent propagation over very long ranges. It has been successfully demonstrated in several experiments with sources localized with accuracies exceeding by two orders of magnitude the Rayleigh limit for depth and the Fresnel limit for range by two orders