Three-year fade and inter-fade duration statistics from the Q-band Alphasat propagation experiment in Madrid

Propagation campaigns are carried out at different frequencies and geographical areas to characterize the slant-path propagation channel. One of the objectives of the Alphasat Propagation Experiment is to evaluate the performance of satellite links that operate in the Q/V band. Since March 2014, the copolar level of the Alphasat Q-band beacon signal has been measured at Universidad Politecnica de Madrid, Spain. The fade dynamics-fade and inter-fade durations-results for three complete years (March 2014 to February 2017) of measurements are presented in this paper. Moreover, the experimental setup and receiver characteristics are described in detail. The collected data (with a mean availability of 97%) can be used to evaluate the atmospheric propagation impairments with a very good degree of accuracy. The probability of occurrence and the fraction of time of fade duration for an average-year have been compared with the ITU-R and CRC models with moderate agreement. For this reason, a modeling effort has been made leading to the conclusion that there is room for improvement in the models.