A Study of Filled and Sparse Line Array Beamformers

摘要

The paper considers various methods of frequency-domain beamforming for a line array of hydrophones. The line array geometries are restricted to uniform sensor spacings (i.e. filled array) or a geometry in which sensors are eliminated from the filled structure (sparse array). The methods to be examined include the conventional phase-to-plane beamformer (CB), the data-adaptive Minimum Variance beamformer (MVB), and the Principal-Solution beamformer (PSB). The beamformer performance is assessed on the basis of two criteria. The first is the ability of the beamformer to map the directionality of the acoustic field. The integration time uesd in producing the map is unrestricted: hence, only first-order beamformer statistics influence the performance. The second criterion is the ability to detect narrowband, directional signals against the noise. Here the integration time is finite, and higher-order beamformer statistics become important. We shall show that the PSB has advantages over the CB for mapping of the directionality. However, no advantage exists in the signal detection application. The MVB provides the directionality map that is least influenced by leakage. However, its detection performance is superior to that of the CB only if the noise field is highly directional. (Author)