Modeling VLF propagation in the Earth-ionosphere waveguide using the discontinuous Galerkin method

Modeling of scattering of very low frequency (VLF, 3-30 kHz) waves from ionospheric disturbances remains a significant computational challenge due to the strong inhomogeneity and anisotropy naturally present at these frequencies. The discontinuous Galerkin (DG) method on unstructured grids can lead to to very efficient formulations in strongly inhomogeneous materials. We discuss a generic method to incorporate any linear, frequency-dependent permittivity or permeability in the nodal DG framework (including PMLs, ferrites, and cold plasmas) and apply the resulting scheme to modeling the VLF scattered field from a density perturbation in the lower ionosphere.