Calculation Method of Electromagnetic Waves Scattering by Dielectric Toroid Meteorological Formations

One of the possible physical mechanisms of so-called “angel” echoes, not visually observed radar discrete reflections from objects, is considered. The vortex flows can be the cause of “angel” echoes. They take out some volume of air with certain radiophysical parameters into the region of space with other radiophysical parameters of the air. Toroidal vortices (vortex rings) have a fairly long lifetime and can move to considerable distances without destruction. The calculation of radio wave scattering diagrams by vortex rings by modern universal programs designed to solve electrodynamic problems and based on the method of moments requires significant computational and time resources. The asymptotic calculation method of the electromagnetic waves scattering by dielectric toroidal formations of large radius is developed. Simulation and comparison of its results with calculations in Altair Feko is carried out, and their well coincidence is shown. The monostatic and bistatic effective scattering areas of vortex rings are calculated for interesting cases in practice. The calculation results for the monostatic location good enough coincide with the results of known experimental works.