A four-year variability study for Ka- And Q-band slant path propagation experiments in Madrid

Abstract

In satellite propagation, variability (the fluctuations of certain parameter or phenomenon over time with respect to its average behavior) is assessed by using some statistical variable such as its variance over the years. Overall, there are few reports on rainfall and attenuation variability and only very few on fade dynamics, due to the need of experimental data for a long period of time with a high availability (a hard task to achieve) to produce meaningful results. Moreover, most of these reports are focused in the Ka-band. Having data with a high availability ( higher than 97 %) for a concurrent period of 4 years in Madrid for KA-SAT (19.680 GHz) and Alphasat (39.402 GHz) propagation experiments, a study on the variability of rainfall rate, excess attenuation and fade and inter-fade number of events is carried out. The results show a high variability of some parameters, confirming the need of performing multi-year experiments to assess statistically stable trends.