Surface Ship, Hull Mounted, Mine Avoidance Sonar

The survivability of Navy tactical surface ships operating in forward shallow water littoral environments largely depends upon the effectiveness of hull-mounted active sonar to detect, classify and localize threat sea mines. Employment of active sonar for mine avoidance in shallow water environments produces strong reverberation returns that degrade detection, classification, and localization performance. In Phase I work AHA demonstrated a significant reduction in near-field reverberation with mid-frequency active in-water test data using a short-time adaptive broadband adaptive beamformer (STABB). Also with that data, AHA demonstrated an order-of-magnitude improvement in angular resolution vs. CBF, significantly improving vertical localization – a key classification clue. In Phase II, AHA will design a STABB-based mine avoidance operating concept, including beamforming, detection, classification, tracking, localization, and data fusion processing; benchmark STABB with standard performance metrics using MF and/or HF active acoustic sea-test data; use STABB outputs and ray-trace model information to image objects in the water column; analyze waveforms in support of object classification with STABB; design and assess the performance of a fused multi-sensor Mine Avoidance system; and, support DD(X) activities to aid in technology transition. Achievement of these Phase-II objectives will include demonstration of PEO-Ships S&T performance thresholds via participation in a peer-reviewed process.