DISCRETE TRANSPARENT BOUNDARY CONDITIONS FOR WIDE ANGLE PARABOLIC EQUATIONS IN UNDERWATER ACOUSTICS

摘要

This paper is concerned with transparent boundary conditions (TBCs) for wide angle "parabolic" equations (WAPEs) in underwater acoustics (assuming cylindrical symmetry). Existing discretizations of these TBCs introduce slight numerical reflections at this artificial boundary and also render the overall Crank-Nicolson finite difference method only conditionally stable. Here, a novel discrete TBC is derived from the fully discretized whole-space problem that is reflection-free and yields an unconditionally stable scheme. A much more detailed version of this article will be published elsewhere.