Ray travel time and distance for the planar polytrope

Ray travel time and distance are determined for the planar polytrope using analytic techniques that are specialized to plane stratified media. It is f ound that an adiabatically stratified polytrope yields non-dispersed wave f ields for a full circuit of a ray through a trapping region. Non-adiabacity , however, leads to dispersion, and a consequent loss of correlation with s uccessive circuits of the trapping region. An acoustic waveguide with fixed boundaries and a similar waveguide containing an isothermal stratified med ium are also examined to illustrate the approach and to highlight various a spects of the ray behavior.