Azimuthal propagation in a nonuniform concentric cylindrical waveguide with application to the Earth--ionosphere waveguide

The problem associated with propagation in the Earth--ionosphere waveguide under geometrically perturbed conditions may be handled using a method outlined earlier for the parallel-plate waveguide. In this communication, the details are outlined, based on a transformation due to Zucker and Cohn. The equations are in the form used by Wait in his treatment aimed at justifying the two-dimensional approach.