In a recent paper published in JGR Space Physics, AER Senior Staff Scientist Alan Ling applied a method for tracing rays in tokamak plasmas to tracing rays in the Earth’s magnetosphere. By appealing to complex geometric optics he addressed the problem of computing power flux from pencil rays using classical geometric optics that occurs when constituent rays exhibit coplanarity. The paper describes the construction of Gaussian beams and the quasi-optical method of tracing such beams. Examples of tracing Gaussian beams from a ground transmitter, a partial beam, and from a satellite location are presented. A median method for dealing with nonviable contributions to the power flux from sections of the beam encountering caustics or otherwise experiencing coplanarity is described. The effect of beam parameter choices on the resulting power flux computation is provided for each of the examples.
A. Ling, M. J. Starks, & J. M. Albert
Journal of Geophysical Research: Space Physics, 127, e2022JA030649, 2022