Annual and annual-worst month attenuation statistics at 11 and 18 GHz on an earth-space path over Delhi

21-23Attenuation data for the period July 1985-Dec. 1989 obtained by 11 and 18 GHz microwave radiometers have been analyzed for annual and annual-worst month (July) attenuation statistics. The worse-month cumulative distribution has been give by the envelope of the highest probability for the month of July, the highest rain occurring month and the subsequent conversion ratios determined. It is shown that a factor between 5 and 6 required to convert from annual-worst month to yearly time percentages. Attenuation for 0.01% of a year (50 min) or 0.1% of the worst month has been evolved as a reliable criterion for communication systems operating at microwave frequencies