Performance evaluation of models for the conversion of rainfall statistics from long to short integration time

The 1-minute integrated complementary cumulative distribution function (CCDF) of rainfall, P(R)1, is a necessary piece of information in the process of rain attenuation estimation for microwave link design. Whenever local 1-minute integrated rainfall data are not available, the conversion of rain rate CCDFs from any integration time T, P(R)T, to P(R)1 is a viable option. This paper presents a comparative performance evaluation of some models for the conversion of the rainfall statistics from long to short integration time, including some methods found in the mainstream literature and a new physically based methodology. The models’ assessment is performed with the aid of an extensive database of rainfall statistics collected from various locations in the world, in different climatic zones. The performance comparison highlights the benefits of using a physical approach to rainfall statistics conversion, as it provides more accurate and stable predictions, in terms of root mean square of the prediction error variable.