Propagation of VLF Radio Waves in a Model Earth‐Ionosphere Waveguide of Arbitrary Height and Finite Surface Impedance Boundary: Theory and Experiment

Abstract

This paper deals with propagation of radio waves in a model multimode waveguide with special applications to VLF propagation in the earth‐ionosphere waveguide. The effective height of the waveguide is assumed to be an arbitrary function of distance along the path of propagation. In this paper a finite surface impedance boundary is devised to simulate the ionosphere boundary. The quasi‐optical approach developed for perfectly reflecting boundaries is generalized to obtain the required solution. These theoretical solutions are compared with experimental data from the model waveguide in which a “day‐to‐night transition” and a localized depression in the effective height of the ionosphere are simulated.