Matched field processing using a large aperture planar towed array

Abstract

Passive detection and localization in shallow water is complicated by high transmission loss and coherent multipath generated by bottom interaction. To compensate for this loss, one must achieve as much array gain as possible. The seismic community has developed large aperture arrays designed for low-frequency operation, which are on the order of 3–10 km by 0.5 km in size. This presentation explores the applicability of these arrays to passive detection and localization of underwater targets using matched field processing (MFP). This approach offers the advantages of a high number of sensors, large gain focusing, and three-dimensional localization through MFP when the propagation environment is well known. This talk presents simulated results of conventional MFP using planar arrays in the presence of surface interferers. This presentation continues showing improvement through adaptive MFP. It then examines the problem of target motion. For these large arrays, robustness to target motion becomes a significant challenge. [This work was sponsored by the Defense Advanced Research Projects Agency under Air Force Contract No. F19628-00-C-0002. Opinions, interpretations, conclusions, and recommendations are those of the authors and not necessarily endorsed by the United States Air Force.]