A Phase-Matched Beamforming Method for Underwater Long Line Arrays

Abstract

The invention provides a phase-matching beamforming method, which uses the frequency domain data of the basic array to design a weighting coefficient matrix, and overcomes the gain of the beamforming array caused by the attenuation of the sound field correlation caused by the fluctuation of the underwater acoustic channel when the underwater long line array is used in the actual sea area In order to solve the drop problem, a higher array gain can still be obtained when the spatial correlation of the received signal decreases. Firstly, the time-domain received data of the underwater long linear array is transformed into the frequency domain, then the weighting coefficient matrix is ​​obtained according to the frequency-domain data matrix, and finally, beamforming is performed. The method of the present invention does not need to perform mode extraction and signal correlation prediction, and does not need to invert the received data covariance matrix, and can still obtain better than conventional beamforming, minimum variance distortion-free response beamforming and beamforming in complex ocean waveguide environments. Eigenvalue beamforming with higher array gain.

Description

technical field [0001] The invention belongs to the technical field of sonar array signal processing, and in particular relates to a phase matching beam forming method suitable for underwater long line arrays. Background technique [0002] Using large-aperture linear arrays to detect underwater targets has its unique advantages. However, due to the influence of the ocean waveguide environment, the spatial correlation of received signals between array elements is weakened, which will lead to a decrease in the array gain of traditional beamforming algorithms, such as conventional beamforming (Conventional Beamformer, CBF), minimum variance distortion-free response beamforming ( MinimumVariance Distortionless Response Beamformer (MVDR) and Eigenvalue Beamformer (EBF), etc., which in turn affect the detection performance of sonar. In response to this problem, L Xie et al. in the literature "L Xie, CSun, X H Liu, G Y Jiang. The array gain of conventional beamformer affected by s...

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Problems solved by technology

HCox proposed a molecular array method in the document "H Cox. Line array performance when the signal coherence is spatially dependent. J. Acoust. Soc. Am. 1973, 54 (6), 1743-1746." In severe cases, a higher array gain than full array processing can be obtained, but sub-array division needs to estimate the signal correlation in advance, and it is at the expense of full array processing performance, which weakens the advantages of underwater long line array detection

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