Ray methods in long-range deep ocean sound propagation.

Abstract

Although ray methods have limitations, they remain extremely important because they provide insight into the underlying wave propagation physics that is difficult, if not impossible, to obtain by any other means. In this talk the utility of ray methods in long‐range deep ocean sound propagation will be discussed and illustrated. Topics to be discussed include ray‐mode duality and action quantization; adiabatic invariance for rays and modes; beamforming and Radon transforms; caustics and catastrophes; travel time sensitivity kernels, Fresnel zones and other measures of ray widths; nonlinear resonances, KAM theory, and mode coupling; the waveguide invariant and its ray equivalent; and beam dynamics—from weakly divergent to explosive. [Work supported by ONR.]