Near-field focused beamforming acoustic image measurement based on deconvolution

In order to improve the resolution and positioning accuracy of multiple sound sources in acoustic image measurement,a near-field deconvolution focus beamforming acoustic image measurement method is presented.Firstly,the near-field two-dimensional generalized convolution mathematical model among the conventional acoustic image measurement results,the objective function and the array directivity function is established.According to the point spread function shift-variant but predictable characteristics in the acoustic map measurement,the convolution problem in the beamforming process is transformed into the original superposition integral problem by pre-storing the point spread function dictionary.The two-dimensional Richardson-Lucy iterative algorithm is used to solve the deconvolution in the case of two-dimensional shift-variant model,and the high-resolution acoustic image measurement processing is realized.The performance of deconvolution,conventional and MVDR acoustic image measurement is compared by simulation and sea test.The results show that the deconvolution algorithm has a focus peak size less than 1/2 of the other two algorithms in 500 iterations.The sidelobe level drops by more than 6 dB.