Electromagnetic Scattering by Artificial Plasma Clouds in the Ionosphere

Vaporized samarium (Sm) has been released in the ionosphere for artificially creating plasma clouds, which may be tailored as radio wave reflectors for over-the-horizon communications. The model of samarium releases needs to be further refined for filling the gap between experimental observations and theoretical simulations. A sophisticated simulation model, so far to date, for samarium release in the ionosphere has been developed, and the redundancy reaction, inversion, and the photochemical reactions are all taken into account. The model results are consistent with experimental observations. Due to the geomagnetic field and neutral wind, the shape of artificial plasma clouds significantly changes. The error of the spherically symmetric reflection model is large. According to the density distribution of plasma clouds, the geometric theory of diffraction (GTD) is introduced here to deal with the electromagnetic scattering. The GTD-based scattering model has been established and used to study the time-space evolution of the ground-received power patterns in this article.