Underwater acoustic imaging with spatial cross correlation for weak noise source identification

A cross-correlation based imaging approach to reconstructing the intensity distribution of noise sources passively is proposed for weak noise source identification in this paper. In the proposed method, all pairs of the received noise signals from noise source radiations are cross correlated first, and then these cross-correlations are delayed-and-summed to recover the noise source image. Since cross-correlation is similar in principle to matched filtering, the proposed method offers the ability of reconstructing weak noise sources. Numerical simulations for resolution analysis and source imaging in the case of point noise source are carried out to verify the validity of the proposed method. Simulation results show that the proposed method achieves a better performance than the conventional beamforming method and not only the signal-to-noise ratio (SNR) enhancement but also the better resolution obtained with the proposed method only using relatively fewer elements.