Full wave modeling of VLF wave scattering and propagation in curvilinear stratified ionosphere

We describe two enhancements to Stanford Full Wave Method (StanfordFWM) for calculation of electromagnetic field radiated into a stratified medium by arbitrarily positioned monochromatic sources [1,2]. In the first part, we consider the problem of scattering on strong ionospheric disturbances. We introduce a novel computational technique which combines StanfordFWM with the method of moments (MoM), instead of the previously used Born approximation method [3]. In the second part, we demonstrate a method to include the curvature of stratification layers into the full-wave approach. This method is used to calculate the attenuation and height gains for ELF/VLF modes in the Earth-ionosphere waveguide. The results are significantly different from those obtained with the flat-Earth assumption, especially for the least attenuated modes.