SUN TRACKER MEASUREMENTS OF ATTENUATION BY RAIN AT 16-GHZ AND 30-GHZ

This paper describes an instrument for measuring attenuation statistics on an earth‐space path simultaneously at 16 and 30 GHz; the high attenuations result from heavy rain. The sun is used as a signal source during the time of day when the sun ordinarily is visible; a measuring range of more than 30 dB is achieved at both frequencies. The brightness temperature of the atmosphere also is measured both day and night. At night the antenna beam is stationary on the local meridian. Daytime brightness temperatures in conjunction with direct attenuation measurements are used to determine the equivalent absorber temperatures which are necessary for the reduction of night brightness temperatures to attenuation values. This paper discusses the measurements made during the first 12 months of operation and gives statistics of these measurements and an analysis of errors in the system. © 1969 The Bell System Technical Journal