Alphasat Aldo Paraboni Propagation Experiment In Graz - Frequency Scaling Analysis

In order to study propagation effects for future satellite communication frequencies, the Alphasat Aldo Paraboni payload includes two beacon transmitters at Ka-band (19.701 GHz) and Q-band (39.402 GHz). Among all atmospheric effects, rain has the biggest impact on signal transmission. Often a single statistical relationship (derived from climatic parameters) between rain rate and specific attenuation is used, but it is well known that the variability of the drop size distribution (DSD) for a given rain rate is considerably large and affects the specific attenuation.Frequency scaling is often applied to determine the instantaneous attenuation at the uplink (higher frequency) from a measured attenuation at the downlink (lower frequency).This paper reports on the propagation and disdrometer measurements carried out in Graz (Austria) during 2014. The instantaneous frequency scaling factor obtained from DSD data is analyzed and the instantaneous frequency scaling ITU-R model is compared against beacon measurements.