Transformation of the modal structure of acoustical field in course of the sound propagation from continental shelf to the deep ocean

The problem of pulse signals propagation from continental shelf to the underwater sound channel of the deep sea is considered. This problem and related physical effects are important for many practical applications of underwater acoustics, including, for instance, acoustical ranging and navigation. Modal structure of acoustical field in various cross-sections of a compound waveguide consisting of a shallow- and a deep-water part is studied. Distributions of acoustical energy over the modes are computed, and the arrival times of various modal components of a pulse signal are estimated at different depths.