Theory of the Terrestrial Propagation of VLF Electromagnetic Waves

Concise theory of radio transmission in the Earth‐ionosphere wave guide

“…The mode function satisfies the differential equation A slightly more general form has been given by Galejs [1972] with a correspondingly more complicated derivation. The field representations derived above for isotropic boundary impedances Zg and Zt have been generalized to anisotropic boundaries in closely related studies by Wait [1963Wait [ , 1974, Galejs [1967Galejs [ , 1972, Al'pert et al [1972], and Ledinegg et al [1976]. In these investigations the ground surface impedance Zg is still a simple complex scalar, but the ionospheric surface impedance Zt then becomes a two by two tensor.…”

“…Very detailed reviews of limited aspects of the subject have appeared within the past decade [e.g., Makarot• et al, 1970;Orlot• and Azarnin, 1970;Al'pert et al, 1972;Galejs, 1972;Wait, 1974]. The interested reader should certainly consult these reviews for more information.…”

“…The interested reader should certainly consult these reviews for more information. (Note that in equation (52) of Wait [1974], e-•'X/2x should be e-:X/2. )…”

Lightning location using the slow tails of sferics

“…As the changes in the day to night ionosphere significantly affect the propagation of the slow tail, the uniform waveguide assumption limits us to computing slow tails that do not cross the day-night terminator. Accounting for the sharp day-night terminator while modeling the waveguide leads to a much more complex model that includes the mode coupling occurring at the transition [Wait, 1974]. Rather than using a new model, we now examine the possibility of using adjusted values for the reflection height and ionosphere conductivity, which are then applied to the uniform waveguide model to represent a waveguide that includes the day to night transition.…”