Nationwide long-term rain rate statistics and empirical calculation of 11-GHz microwave rain attenuation

Two methods are described to obtain long-term (20 years and longer) distributions of 5-minute point rain rates from data published by the National Climatic Center for U.S. locations. A set of simple empirical formulas for converting the distribution of 5-minute rain rates into rain attenuation distributions on 11-GHz radio paths has been deduced from data measured in Georgia. Additional data measured in several other locations also support this empirical formulation. These simple formulas and 5-minute point rain rate distributions are useful for path engineering of 11-GHz radio.