Full wave calculation of ground-based VLF radiation penetrating into the ionosphere

The spatial distribution of electromagnetic field excited by ground-based VLF transmitters with different radiation frequency and power under different geomagnetic parameters and ionospheric parameters are stimulated using the full-wave model constructed in this paper. Focusing on the absorption in the D/E region of the ionosphere, we can conclude that the attenuation of VLF radiation in the waveguide is only affected by the wave frequency in the near field which decreases with the increase of the wave frequency, while the D/E region absorption and total attenuation increase with wave frequency. The variation of the radiation power has no effect on the attenuation in the waveguide and the D/E region absorption. The D/E region absorption decreases with the increase of the geomagnetic field and the dip angle of the geomagnetic field. The D/E region absorption increases with ionospheric electron density and collision frequency.