Doppler-Clutter-Mitigation Processing Navy SBIR FY2015.1 Sol No.: Navy SBIR FY2015.1 Topic No.: N151-034 Topic Title: Doppler-Clutter-Mitigation Processing Proposal No.: N151-034-0665 Firm: Applied Research in Acoustics LLC 1222 4th Street SW Washington, D.C. 20024 Contact: Jason Summers Phone: (202) 629-9716 Web Site: http://www.ariacoustics.com Abstract: To address the need for enhanced Doppler processing to improve the performance of pulsed continuous-wave (CW) waveform processing in the presence of stationary clutter, own-ship induced clutter, and active interference, Applied Research in Acoustics LLC (ARiA) will develop and demonstrate the feasibility of signal- and information-processing algorithms for mitigation of Doppler clutter. ARiA will develop and evaluate (1) a subarray/subspace robust adaptive beamformer (ABF) mitigation of motion-induced Doppler spreading, (2) a novel model-based space-time processor for mitigation of motion-induced Doppler spreading based on a more complete physical model of the physical and signal-processing sources of Doppler clutter, and (3) a robust compressive-sensing beamformer (CSBF) for active-interference mitigation. The Phase I effort will (1) develop Doppler-clutter-mitigation (DCM) processing that will improve the performance of Doppler processing in the presence of stationary clutter, ownship-induced clutter, and active interference; (2) demonstrate that DCM processing can feasibly meet Navy needs by improving the probability of detection and correct classification and reducing false-alert rate (FAR) and operator work load; and (3) establish that DCM processing can be developed into a useful product for the Navy that is compatible with existing hardware (e.g., the AN/SQS-53C) and software architectures (e.g., the AN/SQQ-89A(V)15, BFFS, and MFAFS). Benefits: The new Doppler clutter-mitigation (DCM) processing developed in this work will advance the state-of-the-art to significantly improve detection and classification probability of low SNR targets near the zero-Doppler ridge by reducing the Doppler spread of reverberation and clutter and decreasing the impact of active interference. Results of the Phase I effort will provide a basis for Phase II development and demonstration of prototype software implementations of algorithms on modeled and archived data and Phase III transition of the technology to Navy use for integration with the processing string of the AN/SQQ-89A(V)15 Undersea Warfare (USW) combat system. The signal-processing concepts, algorithms, and software we propose to develop and evaluate are extensible across a wide range of active-sonar platforms and particularly suitable for midfrequency sonars such as the AN/SQQ-89A(V)15 with AN/SQS-53C or AN/SQS-56 hull arrays and multi-function tactical array (MFTA) towed array, the Littoral Combat Ship Anti-Submarine Warfare (ASW) Mission Package (MP), and the AN/SQQ-90 with dual-frequency hull array. Similar gains can also be realized for commercial midfrequency systems used for subbottom profiling, single-beam and multiple-beam (swath) bathymetry, and acoustic seafloor characterization. Return