Shadow‐mapping to study attenuation by rain on satellite microwave links

Abstract

A technique has been developed for generating “shadow maps” (the shadow that an array of showers would cast on the earth's surface) in the microwave radiation from a hypothetical source in a geostationary satellite at specified azimuth and altitude. The input data for this technique are weather‐radar records on digital magnetic tape. To describe and demonstrate the technique and its intended use, this paper contains just one shadow map at high resolution (approaching that of the radar record), one sequence of maps at a lower resolution covering the three hours of one storm‐array passage, and an analysis of the effect that one passage would have had on an earth station and on various path‐diversity pairs. We hope to generate high‐resolution maps for a whole season (summer 1976) and to use them to catalogue and compare the various storm‐array passages that would have a significant effect on slant‐path microwave links.