Extrapolation of point rain-rate distributions

A numerical experiment demonstrates that the results of extrapolating a point rain-rate distribution to lower and higher rain rates using a log-normal approximation are insensitive to the raining probability, which depends on the ambiguous definition of when it is raining. The ambiguity in defining when it is raining, i.e., the arbitrary rain threshold, can therefore be tolerated at least in this application of log-normal representation. It is concluded that the proposed extrapolation technique will be useful in microwave communication system engineering.