Rational linear approximation to the wave equation with bottom interaction

Abstract

A rational linear approximation is used to derive a range‐dependent full‐wave propagation model, much like the parabolic equation, which can handle the dual problem of high angle propagation and bottom interaction. It uses an inexpensive tridiagonal implicit range step for economical calculation in the presence of large gradients, where range steps are necessarily very short. The use of matched cubic splines gives an accurate treatment of reflection and refraction at density and sound‐speed discontinuities. It gives an accurate treatment of propagation from 0° to 45° grazing angle. [Work supported by ONR 486.]