Multipath structure of thetypical under-ice sound channel in Arctic:theory and experiment

Regarding to the typical acoustic environment of the Arctic, this paper proposes a method based on OASES- Bellhop coupled model to rapidly analyze the multipath structure of the under-ice sound channel. Firstly the proposed model refers to ice plate as stratified elastic media with some roughness. Secondly, it uses the perturbation method and Kirchhoff approximation theory to solve the scattering loss due to the sea ice inhomogeneity. In the end, the model predicts the multipath structure of the under-ice channel through Ray theory. The results of the numerical simulation and experiment indicate that the typical Arctic sound channel presents multipath structures due to the sea ice and seabed in the range of 6 kin, respectively. -The sea ice reflection paths are stable and with short multipath delay extension within 14 ms. The seabed reflection paths have relatively weak strength. The proposed OASES-Bellhop coupled model successively predict the amplitude and delay of the multipath structure with small error which indicates the proposed model is able to analyze and predict the multipath structure of the observed acoustic environment.