scholarly journals Investigating Rain Attenuation Models for Satellite Links in Tropical Nigeria

2018 ◽  
Vol 6 (1) ◽  
Author(s):  
Abayomi Isiaka O. Yussuff ◽  
Ibukun E Koleoso ◽  
Nor Hisham Haji Khamis
Keyword(s):  
Rain Attenuation ◽  
Satellite Links ◽  
Attenuation Models

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.

Rain Attenuation Models for Mobile Satellite Communication in Sudan

2020 ◽  
Author(s):  
Arafa Omer Norain Malik ◽  
Mohammad Kamrul Hasan ◽  
Rashid A. Saeed ◽  
Rania A. Mokhtar ◽  
Siti Norul Huda Sheikh Abdullah ◽  
...  
Keyword(s):  
Satellite Communication ◽  
Rain Attenuation ◽  
Attenuation Models ◽  
Mobile Satellite ◽  
Mobile Satellite Communication

Analysis of Selected Earth-Space Rain Attenuation Models for a Tropical Station

2016 ◽  
Vol 3 (2) ◽  
pp. 383 ◽  
Author(s):  
A. I. O. Yussuff
Keyword(s):  
Prediction Models ◽  
Measurement Data ◽  
Daily Rainfall ◽  
Rain Attenuation ◽  
Propagation Path ◽  
Tropical Regions ◽  
Earth Space ◽  
Budget Analysis ◽  
Link Budget ◽  
Attenuation Models

The restrained use of millimeter bands is due to severe rain attenuation. Attenuation is caused when rain cells intersects radio wave’s propagation path; resulting in deep fades. The effect of rainfall is more severe in tropical regions characterized by heavy rainfall intensity and large raindrops; hence, rain attenuation analyses are essential to study rain fade characteristics for use in earth-space link budget analysis, for outage prediction resulting from rain attenuation. Tropical regions are particularly challenged with signal outage, necessitating the formulation and development of suitable prediction model(s) for the region. Therefore, extensive knowledge of the propagation phenomena mitigating system availability and signal quality in these bands are required. Daily rainfall data were collected from the Nigerian Meteorological Services for Lagos for spanning January to December 2010. Results showed that although, the ITU-R model out-performed the other prediction models under consideration, none of prediction models matched the measurement data.

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.

scholarly journals Characterization of Rain Specific Attenuation and Frequency Scaling Method for Satellite Communication in South Korea

2017 ◽  
Vol 2017 ◽  
pp. 1-16 ◽  
Author(s):  
Sujan Shrestha ◽  
Dong-You Choi
Keyword(s):  
South Korea ◽  
Satellite Communication ◽  
Rain Rate ◽  
Rain Attenuation ◽  
Frequency Scaling ◽  
Scaling Method ◽  
Ka Band ◽  
Specific Attenuation ◽  
Rain Specific Attenuation ◽  
Attenuation Models

The attenuation induced by rain is prominent in the satellite communication at Ku and Ka bands. The paper studied the empirical determination of the power law coefficients which support the calculation of specific attenuation from the knowledge of rain rate at Ku and Ka band for Koreasat 6 and COMS1 in South Korea that are based on the three years of measurement. Rain rate data was measured through OTT Parsivel which shows the rain rate of about 50 mm/hr and attenuation of 10.7, 11.6, and 11.3 dB for 12.25, 19.8, and 20.73 GHz, respectively, for 0.01% of the time for the combined values of rain rate and rain attenuation statistics. Comparing with the measured data illustrates the suitability for estimation of signal attenuation in Ku and Ka band whose validation is done through the comparison with prominent rain attenuation models, namely, ITU-R P.618-12 and ITU-R P. 838-3 with the use of empirically determined coefficient sets. The result indicates the significance of the ITU-R recommended regression coefficients of rain specific attenuation. Furthermore, the overview of predicted year-wise rain attenuation estimation for Ka band in the same link as well as different link is studied which is obtained from the ITU-R P. 618-12 frequency scaling method.

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