The effect of localized ionospheric perturbations on subionospheric VLF propagation on the basis of finite element method

The purpose of this paper is to propose the use of finite element method in investigating the effect of localized perturbations in the lower ionosphere on subionospheric VLF propagation. Due to the complexity of the method, we have analyzed only a two‐dimensional case where a localized perturbation lies on the great circle path between the transmitter and receiver. The formulation is first made, and a few computational results are presented in order to indicate the effectiveness of this finite element method.