Global three-dimensional FDTD modeling of impulsive ELF propagation about the Earth

This paper has reported the initial application and validation of the FDTD method to model impulsive ELF propagation within the entire Earth-ionosphere cavity. This technique permits direct, 3-D, time-domain calculation of impulsive, round-the-world ELF propagation accounting for arbitrary horizontal as well as vertical geometrical and electrical inhomogeneities and anisotropies of the excitation, ionosphere, lithosphere, and oceans. We expect that this model will be useful in studies of ELF propagation phenomena which form the physics basis of important remote-sensing investigations of lightning and sprites, global temperature change, and subsurface structures.