AUTOMATIC DETECTION AND TRACKING OF ACOUSTIC SIGNALS OF LOW SNR USING INNOVATIVE BEAMFORMING AND 3-DIMENSIONAL TRACKING ALGORITHMS

Management Communications and Control Incorporated (MCCI) proposes development of an innovative approach to acoustic signal full spectrum direction finding. The approach is based on describing full spectrum signal arrival structure as a distribution of energy about a single spatial frequency. Spatial frequency is defined as the wave number of a reference frequency and reference array sensor pair. Wave numbers of all spectral components of the signal are normalized to the spatial frequency. Their sum is the spatial frequency power density. Development of three complimentary non-conventional techniques for resolving full spectrum spatial frequency power density are proposed: (1) Super CODAR, a signal subspace decomposition direction-finding method; (2) steered covariance beamforming; and (3) open loop adaptive sidelobe cancelled split beam correlation. While the proposed methods are sub-optimum, they offer superior array gain to spatially resolve the full spectrum of signals from directional interference. Further, because temporal phase is demodulated from spatial frequency observations, processing may be extended over greater time and bandwidth apertures limited by spatial frequency stability considerations only. Spatial frequency power density estimates may be tracked, displayed as time, bearing, power histories and smoothed with existing methods. Bearing sorted spectra associated with a spatial frequency track are displayed and smoothed to form unambiguous track sorted target PSDs. MCCI proposes development of Phase I kernel algorithms using the Processing Graph Method (PGM). Algorithms will be executable on MCCI's laboratory signal processing system and Navy commercial and standard resources. Phase I PGM implementation will support transition of algorithms to a commercial software and hardware system supporting PGM.