A universal chart for use in relating ionospheric absorption to phase path and group path

Abstract

The absorption of a radio wave in the ionosphere can be approximated by A = \frac{\omega}{c}\frac{1}{2}\int\frac{Z(\mu' - \mu)}{1 + g} cos \alpha ds , where the integral is along the ray that exists when the normalized collision frequency Z = 0, \mu' and \mu are the group and phase refractive indices, respectively, and \alpha the angle between the wave normal and ray direction. Graphs are presented from which g can be obtained for any values of the ionospheric plasma parameters X and Y .