Theory for the Excitation and Propagation of Electromagnetic Waves Guided by an Elevated Refractive Index Discontinuity in the Troposphere

Abstract

We present an analysis for waves guided by a smooth concave layer in the troposphere. The modal expansion includes both ground wave and Earth detached modes. It is shown that the excitation of the Earth detached modes by a ground based source is very weak. However, there is a possibility that these modes may be excited by a nonuniformity of the layerstructure.Nous prtsentons une analyse de I'excitation et de la propagation d'ondes guidees par une couche concave lisse dans la troposphere. Le developpement modal inclut a la fois une onde se propageant a la surface du sol et des modes detachts de la terre. O n montre que I'excitation de ces derniers modes par une source liee au sol est tres faible. Cependant, il existe une possibilite que I'excitation de ces modes soit due a un defaut d'uniformite dans la structure de la couche.[Traduit par le journal]Can.

Coupled mode analysis for a nonuniform tropospheric wave guide

“…A concrete example is useful to illustrate some of the points we have been trying to make. We It is useful to compare the specific example above with a simple mode matching procedure [Wait, 1968[Wait, , 1974 This type of power normalization of the modes is commonly used in dealing with loss-free structures, such as optical fibers [Marcuse, 1974].…”

“…This so-called adiabatic approximation has been used extensively in underwater sound [Deavenport, 1966;Nagl et al, 1978] and atmospheric acoustic waves [Pierce, 1965]. Only quite recently has the importance of mode conversion been appreciated when dealing with nonuniform natural wave guides [Bahar and Wait, 1963;Wait, 1968Wait, , 1974Bahar, 1971;McDaniel, 1977;Cho and Wait, 1978;Rutherford and Hawker, 1979; E. Ledinegg et al, private communication, 1975]. In this paper we present a self-contained analysis for propagation in a two-dimensional curved model of the earth, where the refractive index is a function of both height and range.…”