Study of earth-ionosphere waveguide effect on lightning pulse with Ray Theory

In this paper we present an half analytic electromagnetic wave model for the study of a lightning-produced VLF/LF pulse propagating in the earth-ionosphere waveguide (EIWG). The property of the lightning pulse propagating in the ionospheric D region is retrieved in frequency domain by using the Transfer Matrix Method coupled with presumed electron density and electron-collision rate profiles. With the retrieved reflection coefficients, a Ray Theory based transfer function from the lightning source to the receiver is derived. The propagation attenuation through spherical ground with presumed conductance is also calculated. The model is applied to the data from a lightning detection network in central China. The simulation results match perfectly with the ground waves and sferics observed by the network, indicating that the model is an efficient tool to investigate the interaction of the lightning pulse with the ionospheric D region and the earth's magnetic field.