First year results on rain attenuation characteristics of satellite links at Equatorial Atmospheric Radar

2004 ◽  
Author(s):  
Y. Maekawa ◽  
T. Fujiwara ◽  
Y. Shibagaki ◽  
T. Sato ◽  
M. Yamamoto ◽  
...  
Keyword(s):  
Rain Attenuation ◽  
First Year ◽  
Satellite Links ◽  
Attenuation Characteristics

scholarly journals Short-term prediction of rain attenuation level and volatility in Earth-to-Satellite links at EHF band

2008 ◽  
Vol 15 (4) ◽  
pp. 631-643 ◽  
Author(s):  
L. de Montera ◽  
C. Mallet ◽  
L. Barthès ◽  
P. Golé
Keyword(s):  
Time Series ◽  
Prediction Error ◽  
Nonlinear Models ◽  
Garch Model ◽  
Rain Attenuation ◽  
Frequency Scaling ◽  
Attenuation Level ◽  
Satellite Links ◽  
Short Term Prediction ◽  
The Cost

Abstract. This paper shows how nonlinear models originally developed in the finance field can be used to predict rain attenuation level and volatility in Earth-to-Satellite links operating at the Extremely High Frequencies band (EHF, 20–50 GHz). A common approach to solving this problem is to consider that the prediction error corresponds only to scintillations, whose variance is assumed to be constant. Nevertheless, this assumption does not seem to be realistic because of the heteroscedasticity of error time series: the variance of the prediction error is found to be time-varying and has to be modeled. Since rain attenuation time series behave similarly to certain stocks or foreign exchange rates, a switching ARIMA/GARCH model was implemented. The originality of this model is that not only the attenuation level, but also the error conditional distribution are predicted. It allows an accurate upper-bound of the future attenuation to be estimated in real time that minimizes the cost of Fade Mitigation Techniques (FMT) and therefore enables the communication system to reach a high percentage of availability. The performance of the switching ARIMA/GARCH model was estimated using a measurement database of the Olympus satellite 20/30 GHz beacons and this model is shown to outperform significantly other existing models. The model also includes frequency scaling from the downlink frequency to the uplink frequency. The attenuation effects (gases, clouds and rain) are first separated with a neural network and then scaled using specific scaling factors. As to the resulting uplink prediction error, the error contribution of the frequency scaling step is shown to be larger than that of the downlink prediction, indicating that further study should focus on improving the accuracy of the scaling factor.

Evaluation of Rain Attenuation Models in Satellite Links under Tropical and Equatorial Climates

2018 ◽  
Vol 16 (2) ◽  
pp. 358-367
Author(s):  
Wheberth Damascena Dias ◽  
Monique Carleti ◽  
Samuel Souza Lima Moreira ◽  
Luciano Leonel Mendes
Keyword(s):  
Rain Attenuation ◽  
Satellite Links ◽  
Attenuation Models

scholarly journals Path Attenuation Calculator for Rain Fade

2019 ◽  
Vol 24 (2) ◽  
pp. 143-150
Author(s):  
Mohanad Abdulhamid ◽  
Waswa Wekesa
Keyword(s):  
Geographical Area ◽  
Rain Attenuation ◽  
Radio Waves ◽  
Weather Phenomenon ◽  
Satellite Links ◽  
Propagating Waves ◽  
Different Types ◽  
Attenuation Models ◽  
Different Levels ◽  
Specific Amount

Abstract Rain as a weather phenomenon is one of the things that greatly affects propagation of radio waves. Above 10 GHz, the attenuation brought about by the interaction of the propagating waves and the rain droplets becomes significant for both terrestrial radio links and satellite links. For this reason, rain attenuation models have been developed to aid in planning purposes for network implementation. The models use statistics to predict the attenuation that is caused by specific amount of rain and also the type of rain. This means that different regions will have different levels of attenuation due to the fact that they experience different types and amount of rain. A couple of models exist including the ITU-R, Moupfouma model, Crane attenuation model and other localized models depending on the geographical area that research data collection and extensive analysis has been conducted on and a comprehensive set of values and factors have been determined that can aid in estimation of attenuation due to rain. This paper seeks to provide a viable means by which a transmission engineer can be able to know the attenuation per kilometer due to the various models. This is achieved by designing a software calculator that provides the output of the attenuation per kilometer (dB/Km) while taking an input of rain rate for the different models available. The calculator is based on visual basic platform and works with forms.

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