A multifrequency inversion method for geoacoustic parameters

Abstract

The effects of the bottom parameters on the sound field are discussed theoretically and two characteristic angles relevant with geoacoustic parameters are put forward. Based on the theoretical analysis of the characteristic angles, a multifrequency inversion scheme is given as follows: High-frequency and far-field data are used to invert the upper bottom parameters first, and then low-frequency and near-field data are used to invert the lower bottom parameters. Simulated geoacoustic inversions based on simulated annealing method and the beam-displacement ray-mode (BDRM) sound propagation model are applied to the test cases from the 1997 Geoacoustic Inversion Workshop. The simulated inversions show that the inversion results of multi-frequency inversions are more accurate and reliable than those of the single-frequency inversions. The multi-frequency inversion scheme is also applied to the experimental data from ’96 China–US Far Yellow Sea Experiment. [Work supported by NSF of China and ONR of USA.]