Ambiguity surface manifestation of downslope converted noise sources

Abstract

Deals with the manifestation of downslope converted continental shelf noise sources (primarily ships) in the matched-field processor (MFP) ambiguity surface. Of interest is how noise sources outside the range of interest leak into the ambiguity surface through the sidelobe structure of the effective MFP beam (or cell) pattern. This study is carried out with simulations using the parabolic equation model. A shallow 18 Hz source is assumed deployed at various locations on the continental slope, 1750 km from a 1000 m long vertical line array. The MFP search window extends in range across 500 km and in depth down to 1000 m. Shallow sources on the slope show up in the MFP ambiguity surface as deep peaks when downslope conversion takes place. Shallow sources at locations on the slope or in deep water adjacent to the slope where downslope conversion does not take place, appear in the MFP ambiguity surface as shallow sources.<>