EXPERIMENTAL RESULTS OF LOCALIZATION OF MOVING UNDERWATER SIGNAL BY ADAPTIVE BEAMFORMING

The problem of weak moving signal localization and tracking in the presence of single motionless strong interference is investigated using the real data of underwater experiment in the Baltic sea (Sept. 1990) with horizontal receiving array of 64 hydrophones and with two independent powerful narrowband sources imitating the signal and interference, Three simple adaptive beamforming methods were employed for experimental data processing, The first one is based on the well-known projection approach to adaptive beamforming, the second method uses the adaptive canceler approach (termed also as dipole pattern method), and the third method combines these approaches. The signal-to-interference power ratio (SIR) threshold of signal localization and tracking is evaluated by a special technique, which allows examination of the considered algorithms with change of the Sm in consecutive order. The results of real data processing show the high possibilities of signal localization in the presence of strong interference, The combined method performs better than the methods considered and enables localization of the signal source up to the SIR similar or equal to -25 dB.