Acoustic vector array wideband direction finding method based on sparse decomposition theory

Abstract

The invention discloses an acoustic vector array wideband direction finding method based on a sparse decomposition theory, and relates to a direction finding technique and implementation method for target broadband continuous spectrum noise in the acoustic vector sensor array detection field. The sparsification idea is introduced to an acoustic vector array direction finding system; a combined sparse constraint is established according to frequency point components in broadband continuous spectrum noise signal bandwidth; and finally, a unified airspace sparse decomposition form is obtained, thereby realizing direction finding of the broadband continuous spectrum noise. According to the method, a relatively-sharp spectrum peak and a low-amplitude noise floor can be formed; when the number of array snapshots is small, the method is stable in performance and can distinguish coherent signal sources; and when the target DOA (direction of arrival) approaches to the array axial direction, the phenomenon of noise floor fluctuations occurring under the condition of low signal-to-noise ratio of a conventional beam forming (CBF) method and a minimum variance distortionless response (MVDR) method does not exist.

Description

technical field [0001] The invention belongs to the field of underwater acoustic signal processing, in particular to an acoustic vector array broadband continuum noise direction finding method based on sparse decomposition theory, which can be used for passive underwater acoustic vector sensor arrays to detect broadband continuum noise signals radiated by targets. Background technique [0002] The noise radiated by various targets on the surface and underwater includes narrow-band line spectrum noise and broadband continuum noise. In the aspect of passive sonar narrow-band line spectrum detection, traditional methods mainly obtain spatial gain through conventional beamforming (CBF) processing in the airspace, so as to complete tasks such as direction finding and detection. For broadband continuous spectrum noise signals, the CBF method cannot be used directly. The usual method is to split the broadband signal into narrowband signals, and then use CBF for direction finding. ...

AI Technical Summary

Problems solved by technology

This processing idea does not make full use of the information of the broadband signal, and its azimuth resolution capability is limited by the Rayleigh limit, so it cannot effectively distinguish two targets located in the main lobe

The target orientation estimation deviation of the minimum variance distortion-free response (MVDR) method is large when the number of array snapshots is low

The above two methods will have fluctuations in the noise floor at low signal-to-noise ratios

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