Review of long-distance radio-wave propagation above 30 mc/s

The purpose of the paper is to summarize the present state of knowledge concerning the factors affecting long-distance radio-wave propagation at frequencies above 30Mc/s. Attention is drawn to various ionospheric and tropospheric propagation mechanisms and their broad characteristics. The account of these special processes is preceded by Sections dealing with selected aspects of ¿normal¿ propagation. A comprehensive Bibliography is included.