Ray Tracing in the Troposphere, Ionosphere and Magnetosphere

: Ray patterns are presented which delineate the propagation of radio signals to large distances by ducting under super-refracting conditions in the troposphere, ionosphere, and magnetosphere. The unity of ducting is emphasized in the sense that the ducts, whether they occur in the troposphere, ionosphere, or magnetosphere, all have formally similar features. This unity follows from the circumstance that the rays which propagate to large distances are those which graze a super-refracting layer at shallow glancing angles and which generally traverse only those regions of the propagation medium where the refractive index deviates but slightly from the free-space value.