Radiometer studies of atmospheric attenuation of solar emission at 19 GHz

Frequencies above 10GHz are proposed for earth-satellite communication links, and the planning and operation of such links require a knowledge of the total attenuation produced by the troposphere under various meteorological conditions. A statistical analysis on the attenuation of solar radio emission measured at Slough, Bucks., England, at 19GHz has been carried out for the period June 1968 to May 1970. Data covering this period are presented to show the percentage time for which the attenuation exceeds various values for three cases: (a) measured data covering the range of zenith angles between 28 and 90° (b) the same data normalised to zenith and to a zenith angle of 70° using a cosine normalisation (c) the measured data obtained within 10° ranges of zenith angle. The longest duration of any fade exceeding 10dB was 17 min, recorded in September 1968.