Study on the Empirical Prediction of 1-min Rain Rate Distribution from Various Integration Time Data

In a wireless channel above microwave frequency, rain attenuation is very important. In order to predict rain attenuation, 1-min. rain rate distribution is required. This paper discusses an appropriate conversion method to estimate 1-minute rain rate from that of other integration time. Based on the measurement data filed in ITU-R WP3J including ETRI data for 6 consecutive years, distributions of rain rate with 1-, 5-, 10-, 20-, 30-minute integration time were analyzed, and parametric relationship between statistical characteristics of 1-minute and other measurement data were investigated to deduce the conversion method. It is shown that this method is applicable globally with good accuracy for 5-, 10-, 20-min integration time. This method was adopted last year as ITU-R WP 3J TEMP document for new recommendation.