Surface impedance concepts of electromagnetic wave propagation in layered isotropic and anisotropic media
Abstract
Integral representations for the electromagnetic field generated by an electric or magnetic dipole line source located within the atmosphere of the twolayer configuration atmosphereionosphere rendered anisotropic by a uniform static (terrestrial) magnetic field are evaluated by the method of steepest descent to give analytical expressions for the far field along the interface of the two media. These expressions are used to calculate the surface impedance tensor for the lower boundary of the ionosphere. The surface impedance tensor permits one to replace the continuity conditions by approximate boundary conditions along the interface. Results obtained for an arbitrary direction of the static magnetic field (arbitrary geomagnetic latitude) are specialized to polar and equatorial zones. For these cases, dependence of attenuation and phase velocity of the first few modes of the earthionosphere waveguide on ionospheric height and on electric properties of the ground (which enter a scalar surface impedance for the ground plane) is shown. TM modes are much more sensitive to electrical properties of the adjoining media than TE modes. Attenuation is lower for propagation from west to east than in the reverse direction. Icy ground causes severe attenuation of TM but not of TE modes. Various other applications of the surface impedance model are reviewed.
 Publication:

Radio Science
 Pub Date:
 October 1982
 DOI:
 10.1029/RS017i005p01159
 Bibcode:
 1982RaSc...17.1159P
 Keywords:

 Atmospheric Attenuation;
 Electromagnetic Surface Waves;
 Electromagnetic Wave Transmission;
 Impedance Measurement;
 Anisotropic Media;
 Atmospheric Stratification;
 Ionospheric Propagation;
 Isotropic Media;
 Propagation Modes;
 Steepest Descent Method;
 Waveguides;
 Communications and Radar