Sparse reconstruction of acoustic interference fringes in shallow water and internal wave environment

To reduce the distortion of acoustic interference fringes caused by internal waves in shallow water, a sparse reconstruction method of acoustic interference fringes is proposed in this paper according to the coupled mode theory. The proposed method consists of two steps: 1) The interference fringes are approximated to the sum of several two-dimension sinusoids, which are sparsely reconstructed by the vector finite rate of innovation method. 2) According to coupled mode theory, two-dimension frequencies related to uncoupled mode pairs do not vary with the location of internal waves. However, two-dimension frequencies related to coupled mode pairs vary with the location of internal waves. So these frequencies are classified into two parts. The uncoupled mode pairs are used to recover the regular interference fringes and estimate the waveguide invariant in the background environment. The coupled mode pairs are used to track the locations of internal waves. The simulation results show that the proposed method can effectively provide interference fringe reconstruction, waveguide invariant estimation, and internal wave tracking in the internal wave environment.