AUTOMATIC DETECTION AND TRACKING OF ACOUSTIC SIGNALS OF LOW SIGNAL-TO-NOISE RATIO (SNR) USING INNOVATIVE BEAMFORMING AND THREE-DIMENSIONAL TRACKING

Conventional Beamforming (CBF) provides optimum signal detection under ideal ocean conditions (single plane-wave in isotropic, spatially incoherent noise). These conditions never exist in real ocean environments. In order to improve on CBF's performance, Neptune Sciences, Inc. (NSI) has developed and Inverse Beamforming (IBF) method which consists of four algorithms: 1) the Fourier Integral Method (FIM) / Fourier Series Method (FSM) beamforming, 2) noise normalization, 3) an eight nearest neighbor peak picker and 4) a three-dimensional M of N tracking algorithm. The theoretical development for each algorithm is given in detail in this proposal. The IBF method has been tested using several different data sets and has produced extremely successful results for narroband, SWATH and broadband energy detection and bearing estimation. The results have been obtained for many different arrays, including a real-time experiment on board a US submarine during RANGEX 1-92. NSI proposes to take this innovative and successful theory, apply it to Navy supplied data from the Fixed Distribution System (FDS), the FDS Deployable (FDSD), or the Advanced Deployable System (ADS) and compare the IBF methods' performance to a baseline performance selected by the Navy.