Propagation Characteristics of VLF Electromagnetic Wave in Earth-ionosphere Waveguide

Based on the propagation theory of VLF electromagnetic wave in earth-ionosphere waveguide, taking VTX-Kolkata propagation path as an example, the propagation characteristics of VLF electromagnetic wave in earth-ionosphere waveguide are studied in this paper. Firstly, the electron density and the collision frequency along the propagation path are obtained through the ionospheric IRI2016 model and NRLMSISE-00 atmospheric model. Then, combined with the SO-FDTD algorithm, the variation of field intensity along the propagation path in a whole day are calculated. Finally, the temporal and spatial variation characteristics of VLF electromagnetic wave on the propagation path are analyzed.