FDTD simulation and experimental result on VLF scattering by ionospheric perturbations in Earth-ionosphere waveguide

Amplitude and phase perturbations on subionospheric VLF signals (known as Trimpi effect) are thought to be due to the scattering of VLF waves by ionization perturbations caused by either the precipitation of higher energy electrons from the magnetosphere, lightning discharge or earthquakes. In this paper, we examine the VLF scattering by simulating the fast Trimpis due to the direct effect of lightning and we calculate amplitude and phase perturbations by such ionospheric perturbations using the conventional FDTD method. Finally, we compare our computational results with the data measured for Japanese sprite events, to estimate the validity of our modeling.