The Ka-band propagation experiments conducted by ONERA in Toulouse (43.57 • E, 1.47 • N) in the southwest of France started in 2009 and is still on-going. The equipment comprises a beacon Earth station, a profiling radiometer, and a rain gauge. The ground station measures the received beacon signal using a 10-Hz sampling rate. The profiling radiometer measures the sky brightness temperatures at five Ka-band and seven V-band channels, surface temperature, surface humidity, and surface pressure. From July 2009 to March 2011, the beacon receiver recorded the 19.7-GHz (horizontal polarization) HotBird 6 beacon signal along a slant path of 38.6 • of elevation angle. Since April 2011, the beacon receiver has been recording the 20.2-GHz (vertical polarization) Astra 3B beacon signal along a slant path of 35.1 • of elevation angle. This paper aims at providing a complete description of the ONERA Data Processing Tool (in particular the methodology followed to retrieve total attenuation) used to compute 4 years (from July 2009 to June 2013) of copolar attenuation statistics.The experimental setup and the characteristics of the Earth-space links are briefly described. The complementary cumulative distribution function (CCDF) of total attenuation for the whole period is presented and compared with ITU-R recommendations. The measured CCDF of the rainfall rate is computed and compared with ITU-R Rec. P.837 and will also be used as input for the rain attenuation model given in ITU-R Rec. P.618. The measured CCDFs of total attenuation duration and total attenuation slope are also presented.Index Terms-Astra 3B, propagation, fade duration, fade slope, HotBird 6, Ka-band, rainfall rate, satellite communication systems, total attenuation. 0018-926X

This set of two companion papers aims at providing a statistical framework to quantify the inter-annual variability observed on the statistics of rain attenuation or rainfall rate derived from Earth-space propagation measurements. This part I is more specifically devoted to the theoretical study of the variance of estimation of empirical complementary cumulative distribution functions (ECCDFs) derived from Earth-space rain attenuation or rainfall rate time series. To focus the analysis on the statistical variability but without loss of generality, synthetic rain attenuation time series are considered. A large variability on the ECCDFs, which depends on the duration of the synthetic data, is first put into evidence. The variance of estimation is then derived from the properties of the statistical estimator. The formulation is validated numerically, by comparison with the ECCDF variances derived from the synthetic data. The variance of the fluctuations around the CCDF is then shown to be dependent on the average of the correlation function of the time series, on the probability level and on the measurement duration. This variance of estimation is needed as a prerequisite in conjunction with the knowledge of the climatic variability to characterize the yearly fluctuations of propagation statistics computed from experimental time series. The extensions from simulations to experiments as well as the application to system planning are detailed in part II.

This set of two companion papers aims at providing a model for the inter-annual variability of earth-space propagation statistics and for the inherent risk and CIs. In part I, it was proposed to model the yearly variance σ² of empirical complementary CDFs so that σ 2 p ð ÞC the inter-annual climatic variance and p the long-term probability. Particularly, an analytical formulation of σ 2 E was derived and parameterized from synthetic rain attenuation data. Considering the statistical framework developed in part I, this part II is specifically devoted to the parameterization of the variance of estimation σ 2 E from experimental data of rain attenuation and rainfall rate. Then, a methodology to model and parameterize worldwide the inter-annual climatic variance σ 2 C is presented. The model of yearly variance of the empirical complementary CDFs σ 2 ¼ σ 2 C þ σ 2 E is finally compared against yearly experimental variances derived from data collected worldwide. The knowledge of this variability is very useful for system design as it allows the risk on a required availability and associated with a given propagation margin to be quantified.