EXPERIMENTAL RESULTS OF LOCALIZATION OF MOVING UNDERWATER SIGNAL BY ADAPTIVE BEAMFORMING

The problem of weak moving signal localization and tracking in the pre sence of single motionless strong interference is investigated using t he real data of underwater experiment in the Baltic sea (Sept. 1990) w ith horizontal receiving array of 64 hydrophones and with two independ ent powerful narrowband sources imitating the signal and interference, Three simple adaptive beamforming methods were employed for experimen tal data processing, The first one is based on the well-known projecti on approach to adaptive beamforming, the second method uses the adapti ve canceler approach (termed also as dipole pattern method), and the t hird method combines these approaches. The signal-to-interference powe r ratio (SIR) threshold of signal localization and tracking is evaluat ed 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 localizatio n in the presence of strong interference, The combined method performs better than the methods considered and enables localization of the si gnal source up to the SIR similar or equal to -25 dB.