Review of slant path propagation mechanisms and their relevance to systems performance

The purpose of the paper is to present a broad overview of propagation effects for frequencies predominantly within the 30 MHz to optical range, but excluding detailed discussion of depolarisation mechanisms which have been reviewed elsewhere. Emphasis is placed on atmospheric effects of direct relevance to systems design and operation, particularly for satellite communication systems. The topics considered include atmospheric attenuation, noise, scintillation, Faraday rotation and their frequency dependence. Various interference mechanisms are described and a summary of prediction methods relating to single-site slant path attenuation, frequency scaling and diversity operation is provided. A knowledge of the propagation characteristics at frequencies higher than those studied in depth hitherto is of crucial significance to the development of systems which embrace a wide variety of applications, especially in the field of remote sensing.