Two-way solution of underwater sound propagation problem in two and three-dimensional environment by pseudodifferential parabolic equation technique

The paper presents some recipes for underwater sound calculations in 2D and 3D ocean models with sound speed and density slowly varying with horizontal coordinates and arbitrary in depth including a nonhomogeneous liquid model of bottom. These recipes are based on the idea of WKB-like factoring and the extensive use of high order Pade approximations for numerical solving of arising pseudodifferential equations. The author starts from the essentially 2D problem of acoustical wave propagation in a three-dimensional liquid waveguide translationally invariable on the y cartesian coordinate without currents