  The dual-channel sound speed profiles of the Chukchi Plateau and the Canadian
Basin have become current research hotspots due to their excellent
low-frequency sound signal propagation ability. Previous research has mainly
focused on using sound propagation theory to explain the changes in sound
signal energy. This article is mainly based on the theory of normal modes to
study the fine structure of low-frequency wide-band sound propagation
dispersion under dual-channel sound speed profiles. In this paper, the problem
of the intersection of normal mode dispersion curves caused by the dual-channel
sound speed profile (SSP) has been explained, the blocking effect of seabed
terrain changes on dispersion structures has been analyzed, and the normal
modes has been separated by using modified warping operator. The above research
results have been verified through a long-range seismic exploration experiment
at the Chukchi Plateau. At the same time, based on the acoustic signal
characteristics in this environment, two methods for estimating the distance of
sound sources have been proposed, and the experiment data at sea has also
verified these two methods.
