Current submarine acoustic intercept receivers provide inadequate detection and localization performance against active target emissions and are also highly susceptible to false alarms from clutter sources such as biologics. The proposed system will overcome these limitations by utilizing data from all available sensor suites, employing advanced signal processing and classification algorithms, and applying modern localization techniques. This system will exploit "wavefront curvature processing" techniques by using a suite of multisensor correlators, operating in parallel, to determine the time differences in an active signal arriving at the various submarine sensors. The multichannel correlators include a leading-edge detector for CW signal detection and a broadband correlator for FM-type signals (e.g., hyperbolic frequency modulated). Utilizing data from hydrophones located along the length of the submarine (e.g., AN/BQA-8, CRH, and WLR-9) sensor aperture will be maximized, thus improving target localization measurements such as bearing and range. Furthermore, detection ranges will be increased by using beamformed data from the wide-aperture array and/or spherical array. The proposed system will provide the United States Navy with a unique and cost-effective method of automatically detecting, localizing, and classifying active acoustic emissions from targets of interest. This system will demonstrate the feasibility of using current submarine sensors to solve crucial active intercept receiver needs.
