Abstract:
Matched-field processing (MFP) is a generalized beamforming. Instead of using plane-wave replica vectors in the plane-wave beamforming, in MFP, an acoustic model is used to calculate replica vectors in a search space. In addition to azimuthal and elevation information, which can be obtained by plane-wave beamforming, MFP also provides range and depth information. In active systems, scattered signals are usually modeled by two-way, source-to-scatterer and scatterer-to-receiver, propagation. Assuming that scatterers are illuminated and reradiate energy as point sources, the scattering field can be characterized by using just one-way, scatterer-to-receiver propagation. Passive MFP can then be used to map the spatial distribution of the scatterers. A shallow-water experiment took place off the Gulf of Mexico in November 1995; reverberation was measured on an L-shaped array from a bottomed cw source. Passive MFP was used to characterize the spatial distribution of the measured reverberation. [Work supported by U.S. Navy.]