Inversion for the environmental parameters in shallow water using warping transforms

The normal modes of the impulsive signals propagating in shallow water waveguide can be separated using warping transforms. It facilitates the extraction of the dispersion curves of normal modes. The warping transform is applied to the signals received by a single hydrophone collected in the South China Sea during the tomography experiment in 2010. The dispersion curves are extracted using Wigner-Ville Distribution. It demonstrates that the isolation of normal modes can eliminate the intercross interference of Wigner-Ville Distribution effectively. By matching the arrival time differences of normal modes with the numerical results, both the sound speed profile of water and the acoustic parameters of sediment are well inverted. The validity of inversion was evaluated by the posteriori probability. The inverted sound speed profiles of sea water are consistent with the experimental measurements. It is shown that the inversion scheme can provide a valid and stable environmental estimation.