Experimental assessment of slant-path rain attenuation variability in the Ka-band

Abstract

This study is based on the results of a slant-path Ka-band propagation experiment carried out in Madrid, Spain, regarding rain attenuation, which is the main propagation impairment in this frequency band. The experimental and statistical results correspond to seven complete years of measurements, a period large enough to accomplish a comprehensive analysis in order to characterize the variability of rain rate and attenuation. It is shown that year-to-year variability is significant in temperate climates as Madrid's. The aforementioned significance is also apparent with regards to seasonal, monthly, worst-month and hourly variability concerning rain attenuation, which are also discussed and related when possible to the variability of the rain phenomena, either represented by the total amounts of rainfall in the different periods or by rain rate statistics.Report of COST Action 255 [4], or the more recent National Technical University of Athens model [5], or the Synthetic Storm Technique (SST) [6], in addition to the global models for rain rate included in ITU-R Rec. P. 837-6 [7]. Procedures to predict worst-month statistics from average-year predictions or measurements are described in ITU-R Rec. P. 841-4 [8].Thus, the variability of propagation phenomena is not well-addressed in propagation models. Regulatory documents, such as [9,10], partially deal with this subject, which is of growing interest, as shown for example in [11]. Studies on the variability of the propagation measurements from experimental results are very scarce, being [12][13][14] some of the few examples that can be found in the literature. Another approach is the simulation of propagation results starting from long-term rain rate data that are converted into attenuation data using the SST. The variability of the resulting propagation results can be analyzed as was performed, for example, in [15,16]. The variability of rain rate statistics has also been addressed in a few papers [17][18][19][20][21].In this paper, the variability of rain rate and rain attenuation is assessed, making use of the results of a long-term propagation experiment carried out in Madrid, Spain. The Ka-band beacon of the Eutelsat Hot Bird 13A satellite (previously known as Hot Bird 6) has been continuously measured since June 2006 to the first days of July 2013, when the beacon was switched off as part of the process of reconfiguring the satellite to a different orbital position. The period of measurements includes seven complete years, which allows a comprehensive characterization of the propagation channel. The minimum number of years of measurements needed to take into account the natural variability of the rain phenomena and their effects on propagation has been discussed for a long time. A study of long-term rain rate data [17] concludes that seven is the minimum number of years for which most of the averages (of individual distributions) fall within the 5-95% confidence limits of the long-term (49 years) distribution. According to this study, longer periods, such as 1...

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

“…However, because of the large yearly variability of rain phenomena 31,32 and in particular in Madrid as shown in Garcia-Rubia et al, 33 3 years is too short a period to obtain a reliable estimation of the average year rain regime. In fact, the period has been markedly dry, in comparison with longer-term statistics, in particular with regards to high rain-rate convective events, which have the most relevant impact in propagation.…”

Propagation From Geostationary Orbit Satellite to Ground Station Considering Dispersive and Inhomogeneous Atmospheric Environments

“…The atmospheric environments have been monitored using radiosonde, ionosonde, magnetometer, and solar flux monitor [9,10]. In addition, atmospheric absorption and rain attenuation have also been measured or calculated to estimate the influence of the troposphere and ionosphere on the wave propagation [11][12][13][14][15][16][17]. Atmospheric attenuation of electromagnetic waves was measured at 58, 94, and 122 GHz by the Czech metrology institute, while at 19.7 GHz by Universidad Politécnica de Madrid using the Eutelsat Hot Bird 13A Ka-band beacon [11,12].…”

Rain Attenuation Study at Ku-Band over Earth-Space Path in South Korea

“…The site diversity techniques are studied in South East Asia [25]. The statistical variation has been assessed from the propagation experiment that was carried out in Madrid, Spain [26]. A channel model has been developed to predict time series of rain attenuation and the obtained rain rate and attenuation statistics at tropical and temperate regions are compared [27].…”