Guiding of electromagnetic waves by uniformly rough surfaces: Part II

Using the model of a single rough surface described in Part I, the influence of curvature is considered. The starting point is a residue-series solution for a vertical dipole over a sphere with an arbitrary surface impedance. It is shown that the curvature has a profound influence on the nature of the surface wave, although it uniformly approaches the conditions for a plane boundary as the radius of curvature approaches infinity. The propagation between the space bounded by two parallel uniformly rough surfaces is also considered. This is treated first for plane boundaries and then for concentric spherical boundaries. The latter model is useful in explaining certain experimental data on the terrestrial propagation of VLF radio waves.