Worst-month statistics of attenuation over a diffraction path

On the basis of attenuation measurements carried out over a double knife-edge diffraction path, worst-month statistics were estimated using a full set of monthly probability values obtained from 30 months of data at two frequencies in the VHF band. The probability relationship between annual and worst-month statistics, as well as the cumulative probability of their ratios, was evaluated, and empirical formulations were arrived at. The correlation between the ratio of worst month to annual probability and the annual probability was also estimated and compared with the empirical relationship suggested by CCIR.<>