Certain aspects of tropospheric propagation in planning of transhorizon radio-relay and space telecommunication systems

Characteristics of radio signal transmission in the troposphere are considered in the context of planning a radio communication system. Attention is given to the effects of refraction including ray bending, variation in the refractive index gradient, and amplitude, phase, and angular scintillations; the effects of diffraction; the effects of scattering; and the effects of absorption including absorption by oxygen and water vapor, and attenuation by precipitation. A number of research projects carried out in India and elsewhere dealing with these problems of tropospheric propagation are described.