Abstract
This paper reports the application of an efficient finite-difference time-domain (FDTD) algorithm to model impulsive extremely low frequency (ELF) propagation within the entire Earth-ionosphere cavity. Periodic boundary conditions are used in conjunction with a three-dimensional latitude-longitude FDTD space lattice which wraps around the complete Earth-sphere. Adaptive combination of adjacent grid cells in the east-west direction minimizes cell eccentricity upon approaching the poles and hence maintains Courant stability for relatively large time steps. This technique permits a direct, three-dimensional time-domain calculation of impulsive, round-the-world ELF propagation accounting for arbitrary horizontal as well as vertical geometrical and electrical inhomogeneities/anisotropies of the excitation, ionosphere, lithosphere, and oceans. The numerical model is verified by comparing its results for ELF propagation attenuation with corresponding data reported in the literature.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
