Global formulation of the Synthetic Storm Technique to calculate rain attenuation only from rain rate probability distributions

Satellite communication links at millimeter wave frequencies can be affected by huge rain attenuation. For a reliable design, we need to know at least the probability distribution (pdf) of exceeding a given value, A (dB), of rain attenuation in a slant path. Instead of long and expensive measurements of beacon attenuation, we use prediction models which estimate rain attenuation in a given radio link from on-site, or area, long term rain rate. However, there is still no consensus on which model is the most accurate and reliable. In fact, most prediction models of rain attenuation pdf, based on rain rate pdf, when tested against concurrent satellite beacon measurements, show very similar large errors. The Synthetic Storm Technique (SST), on the contrary, is a powerful and accurate tool that can produce all the necessary statistics of rain attenuation. Starting from time series of rain rate R (mm/h), collected at a site with a rain gauge, the SST can generate rain attenuation time series at any frequency and polarization, and for any slant path above about 10°, as long as the hypothesis of isotropy of the rainfall spatial field holds in the long term. Recently, we have found that the pdf generated by the SST can be quite well reproduced by a simple relationship