Direction-finding of coherent sources via ‘particle-velocity-field smoothing’
Jun Yong Tao, Wen-xiu Chang, Y. Shi · IET Radar Sonar & Navigation · 2008
A new ‘particle-velocity-field smoothing’ (PVFS) algorithm is proposed to decorrelate up to three coherent sources for azimuth-elevation direction-finding using vector-hydrophones in the underwater acoustic medium. The coherency among the incident sources would reduce the data correlation matrix's rank to below the number of incident sources, but this proposed algorithm restores the rank by summing the individual particle-velocity-field component's data correlation matrices. This scheme uses identically oriented underwater-acoustic vector-hydrophones, its locations may be arbitrary. Each underwater-acoustic vector-hydrophone consists of two or three collocated but orthogonally oriented velocity-hydrophones, and a pressure-hydrophone. In contrast to the customary ‘spatial smoothing’ technique, this proposed PVFS algorithm does not reduce the array's spatial aperture and does not require any ‘virtual array interpolation’ even for an irregularly shaped array grid. Monte Carlo simulations verify this proposed scheme's efficacy.