LF daytime earth ionosphere waveguide calculations

This report presents results based on waveguide formalism of a numerical study of daytime propagation in the low frequency (lf) band (30-300kHz). Results are presented for the vertical electric field produced by vertical electric dipole excitation. Ground-to-ground, air-to-air, ground-to-air, and air-to-ground configurations are considered. The results point out the severity of multipath fading, even under daytime conditions, for the upper lf band. The results should be particularly useful as a basis against which to compare the results of alternative methods. Minor waveguide modifications which allow for treatment of whispering gallery type modes are discussed. For the prototype ionosphere considered in this study there is no (low loss) mode of propagation of the latter type.