Effects of the atmosphere [CCIR propagation studies]

During the last Study Period (1986-1990), IWP 5/3 has examined for the CCIR a wide range of atmospheric effects on the propagation of radiowaves, in order to improve the radiometeorological content of Volume V, some of which will be considered in this paper. Such studies have included basic meteorological data, the omnipresent effects of the clear atmosphere, both as a refractive and as an absorptive medium, and the effects of rain, which become of dominant importance at the higher frequencies now being actively considered for future systems. In this latter case, a wise range of data are becoming available or are anticipated, from which improved prediction procedures can be developed and refined. Accordingly, IWP 5/3 has not only studied which particular variable (or parameter) should be employed to evaluate the effectiveness of such prediction procedures, but has also developed a method whereby the data itself can be assessed