Results on the Detection of Narrow-Band Low-Level Signals in a Ship-Induced Noise Field Using High-Resolution Beamforming

摘要

In this report the performance of a high-resolution beamformer is compared to that of the conventional beamformer in detecting a low-level narrow-band signal in the vicinity of a number of high-level noise sources. This scenario may arise in areas where shipping noise is predominant, the acoustic field being dominated to a large part by the contributions of individual ships. In this study a comparative detection performance test is conducted with simulated source embedded in a real ship-induced noise field and received on a 64-element towed array. The results shown suggest that in such noise fields the detection performance of the conventional planewave beamformer is greatly reduced due to a lack of resolving power. High-resolution techniques may overcome this difficulty and a detection improvements of 5% to 20% is obtained in the detection of a low-level target in the frequency range below 250 Hz. When the signal-to-noise ration increases the performance of both algorithms is comparable. NATO furnished (rh)