scholarly journals Evaluation of Concurrent Variation in Rain Specific Attenuation and Tropospheric Amplitude Scintillation Over Akure, Southwest Nigeria

2021 ◽  
Author(s):  
Ayodeji Gabriel Ashidi ◽  
Joseph Sunday Ojo ◽  
Oluwaseyi Julius Ajayi ◽  
Toluwalope Mary Akinmoladun
Keyword(s):  
Communication Systems ◽  
Satellite Communication ◽  
Signal Amplitude ◽  
Rain Attenuation ◽  
Coefficient Of Determination ◽  
Integration Time ◽  
Radio Communication ◽  
Amplitude Scintillation ◽  
Specific Attenuation ◽  
Rain Specific Attenuation

AbstractRain constitutes a major limitation to the performance and use of terrestrial and satellite communication systems with operational frequencies greater than 10 GHz. The situation gets further complicated by fast fluctuations in the received signal amplitude due to in homogeneities in atmospheric weather conditions; a phenomenon known as amplitude scintillation. The concurrent evaluation of the two phenomena guarantees a better fade margin determination for the planning of radio communication over any location. This work employs 3 years of in-situ measurement of temperature, humidity, rainfall rate and rainfall amount for the estimation of tropospheric amplitude scintillation and rain specific attenuation over Akure (7.17° N, 5.18° E, 358 m) South West Nigeria. Davis vantage pro weather station at 1-min integration time was used for the measurement and the ITU models for rain specific attenuation (ITU-R P.838-3) and amplitude scintillation (ITU–R 618-13) were employed for the estimation. Time series and statistical analyses of the phenomena show that rain attenuation is the more prominent cause of signal degradation at Ku-band frequencies. Nevertheless, the need to make an extra fade margin allowance of about 0.25 dB due to amplitude scintillation fade subsists to forestall any loss of synchronization on the link. Also, a 3-parameter power-law expression developed for estimating amplitude scintillation fade from rain attenuation performed excellently well, as indicated by average root mean square error (RMSE) and coefficient of determination (R2) values of 0.002151 and 0.8747, respectively.

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.

scholarly journals Rain Rate Distributions for Microwave Link Design Based on Long Term Measurement in Malaysia

2018 ◽  
Vol 10 (3) ◽  
pp. 1023 ◽  
Author(s):  
Islam Md Rafiqul ◽  
Md Moktarul Alam ◽  
Ali Kodhim Lwas ◽  
Sarah Yasmin Mohamad
Keyword(s):  
Communication Systems ◽  
Rain Rate ◽  
Prediction Models ◽  
Complex Structure ◽  
Satellite Communications ◽  
Rain Attenuation ◽  
Integration Time ◽  
Radio Link ◽  
Radio Communication ◽  
High Frequency Microwave

Attenuation due to rain is an important constraint in microwave radio link design especially at frequencies above 10 GHz. It restricts the path length of radio communication systems and limits the use of higher frequencies for line-of-sight microwave links and satellite communications. In order to predict the attenuation due to rain accurately rainfall intensity is required with 1-minute integration time. Rainfall is a meteorological phenomenon with complex structure due to its variability in space, duration and occurrence frequency, particularly in tropical and equatorial regions. Since, the statistical distribution of rain attenuation is obtained from the rain rate distribution for the region considered, it should be noted that the accuracy of the rain rate measurement affects the accuracy of the attenuation estimation. This paper presents rain intensity with 1-minute integration time measured for 6 years in Malaysia, it’s distribution, comparison with other prediction models and impact on high frequency microwave links.

CLEAR SKY DIURNAL BEHAVIOR OF TROPOSPHERIC SCINTILLATION AT KU-BAND SATELLITE COMMUNICATION IN EQUATORIAL MALAYSIA

2015 ◽  
Vol 77 (10) ◽  
Author(s):  
Ibtihal F. El-Shami ◽  
Hong Yin Lam ◽  
Jafri Din ◽  
Siat Ling Jong
Keyword(s):  
Communication Systems ◽  
Satellite Communication ◽  
Prediction Models ◽  
Elevation Angle ◽  
Signal Amplitude ◽  
Radio Communication ◽  
Significant Discrepancy ◽  
Comparison Results ◽  
Diurnal Behavior ◽  
Tropospheric Scintillation

Tropospheric scintillation is referred to rapid fluctuation of received signal amplitude. It can cause propagation impairments that affect satellite communication systems operating at above 10 GHz of frequency. In this work, we have exploited 1 year of measured broadcasting signal data collected in Johor, Malaysia to investigate the effects of scintillation intensity on a SatCom system operating at 11.075 GHz with its links pointed towards the MEASAT-1 satellite (an elevation angle of 75.61°). We have investigated the behavior of this scintillation amplitude through the classification and analysis of a time-series satellite broadcasting signal and have then compared the statistical results with existing scintillation prediction models. The comparison results indicate that there is a significant discrepancy between measured data and those models and that the performance of these prediction models does not appear to be satisfactory, with the exception of the ITU-R and the Ortgies Refractivity model. In addition, we have investigated the diurnal behavior of the scintillation intensity at four different periods of the day and proposed a modified Marzano model to accommodate local meteorological input parameters. The models performances are assessed against the available measurement dataset. The proposed models provide system operators and radio communication engineers with critical information on the fluctuations of tropospheric scintillation variance on the satellite signal during a typical day taken into the account of local meteorological peculiarities.

scholarly journals Analysis of Fade Dynamic at Ku-Band in Malaysia

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Siat Ling Jong ◽  
Michele D’Amico ◽  
Jafri Din ◽  
Hong Yin Lam
Keyword(s):  
Communication Systems ◽  
Satellite Communication ◽  
Heavy Rain ◽  
Rain Attenuation ◽  
Time Interval ◽  
Radio Communication ◽  
System Operator ◽  
Typical Day ◽  
One Year ◽  
Ku Band

This work investigates fade dynamics of satellite communication systems in equatorial heavy rain region based on a one year of Ku-band propagation measurement campaign carried out in Universiti Teknologi Malaysia (UTM), Johor, Malaysia. First order statistics of rain attenuation are deduced and the results are found to be in good agreement with those obtained from other beacon measurements gathered within the same area (Kuala Lumpur). Moreover, the fade duration and slope statistics of the satellite signal variations are also carefully derived and subsequently compared with the ITU-R recommendation model. Such information is useful for the system operator and radio communication engineer for the design of appropriate fade mitigation techniques as well as the quality of service that could be offered to the user (according to the time interval for a typical day). Further evaluation on the performances of several ITU-R models in the heavy rain region are needed based on the measurement database available of this climatic region.

scholarly journals Rainfall rate and rain attenuation contour maps for preliminary “Simon Bolivar” satellite links planning in Venezuela

DYNA ◽  
2019 ◽  
Vol 86 (209) ◽  
pp. 30-39
Author(s):  
Angel Dario Pinto Mangones ◽  
Nelson Alexander Pérez García ◽  
Juan Manuel Torres Tovio ◽  
Eduardo José Ramírez ◽  
Samir Oswaldo Castaño Rivera ◽  
...  
Keyword(s):  
Communication Systems ◽  
Satellite Communication ◽  
Rain Rate ◽  
Rain Attenuation ◽  
Rainfall Rate ◽  
Integration Time ◽  
Contour Maps ◽  
Simon Bolivar ◽  
Satellite Links ◽  
Wireless Communications Systems

Predicting precipitation rate and rainfall attenuation are key aspects in planning and dimensioning of wireless communications systems operating at frequencies above 10 GHz, such as satellite communication systems at Ku and Ka bands. In this paper, contour maps of rainfall rate and rain attenuation are developed for the first time in Venezuela, based on 1-min rain rate statistics obtained from measurements carried out in Venezuela over at least 30 years period with a higher integration time and using Rice-Holmberg model, refined Moupfouma-Martin model and Recommendation ITU-R P.837-7, for rain rate estimation and Recommendation ITU-R P.618-13, Ramachandran-Kumar model, Yeo-Lee-Ong model and Rakshit-Adhikari-Maitra model, for rain attenuation prediction in “Simon Bolivar” satellite links in Venezuela. The overall results of both types of maps represent a useful tool for preliminary planning of those links in the country, specifically, in Ku and Ka bands

scholarly journals Fog and rain attenuation characterization and performance of terrestrial free space optical communication in Akure, Nigeria

2020 ◽  
Vol 4 (3) ◽  
pp. 125-134
Author(s):  
Ajewole M. O ◽  
Owolawi P. A ◽  
Ojo J. S ◽  
Adetunji R. M.
Keyword(s):  
Free Space ◽  
Communication Systems ◽  
Outer Space ◽  
Rain Attenuation ◽  
Integration Time ◽  
Free Space Optical ◽  
High Data ◽  
Space Optical Communication ◽  
And Performance ◽  
One Year

Reliable broadband communication requires secure high data rate and bandwidth links. With the observedincrease in broadband users, known communication systems such as RF and microwave links cannot promise suchrequirements due to link interference and low bandwidth. A current communication system that promises suchrequirements and more is Free Space Optical (FSO) communication. This system basically involves the transmissionof signal-modulated optical radiation from a transmitter to a receiver through the atmosphere or outer space. However,location-variant atmospheric channel degrades the performance of an FSO system under severe atmosphericconditions, thus necessitating local atmospheric attenuation studies.This paper presents the characterization of both fog- and rain-induced attenuation and the performance ofan FSO system in a terrestrial terrain at Akure, Nigeria. One-year archived visibility data and in-situ measured 1-minute integration time rain rate data obtained from Nigerian Meteorological Agency (NIMET) and the Departmentof Physics, Federal University of Technology, Akure were used to compute the fog- and rain-induced specificattenuations using Kruse model and Carboneur model respectively. The performance of the FSO system is analyzedthrough link margin by using the parameters of a commercial optical transceiver, Terescope 5000.

scholarly journals Fog and Rain Attenuation Characterization and Performance of Terrestrial Free Space Optical Communication in Akure, Nigeria

2019 ◽  
Vol 4 (3) ◽  
pp. 125-134
Author(s):  
Joseph Sunday Ojo ◽  
Owolawi P. A. ◽  
Ajewole M. O. ◽  
Adetunji R. M.
Keyword(s):  
Free Space ◽  
Communication Systems ◽  
Outer Space ◽  
Rain Attenuation ◽  
Integration Time ◽  
Atmospheric Conditions ◽  
Free Space Optical ◽  
High Data ◽  
Space Optical Communication ◽  
And Performance

 Reliable broadband communication requires secure high data rate and bandwidth links. With the observed increase in broadband users, known communication systems such as RF and microwave links cannot promise such requirements due to link interference and low bandwidth. A current communication system that promises such requirements and more is Free Space Optical (FSO) communication. This system basically involves the transmission of signal-modulated optical radiation from a transmitter to a receiver through the atmosphere or outer space. However, location-variant atmospheric channel degrades the performance of an FSO system under severe atmospheric conditions, thus necessitating local atmospheric attenuation studies. This paper presents the characterization of both fog- and rain-induced attenuation and the performance of an FSO system in a terrestrial terrain at Akure, Nigeria. One-year archived visibility data and in-situ measured 1-minute integration time rain rate data obtained from Nigerian Meteorological Agency (NIMET) and the Department of Physics, Federal University of Technology, Akure were used to compute the fog- and rain-induced specific attenuations using Kruse model and Carboneur model respectively. The performance of the FSO system is analyzed through link margin by using the parameters of a commercial optical transceiver, Terescope 5000.

Seasonal and Diurnal Variation on Tropospheric Scintillation at Ku-Band in Tropical Climate

2016 ◽  
Vol 6 (4) ◽  
pp. 1710
Author(s):  
Ibtihal Fawzi Elshami ◽  
Jafri Din
Keyword(s):  
Communication Systems ◽  
Satellite Communication ◽  
Elevation Angle ◽  
Signal Amplitude ◽  
Clear Sky ◽  
South West Monsoon ◽  
One Year ◽  
Tropospheric Scintillation ◽  
Propagation Measurement ◽  
Ku Band

Tropospheric scintillation is a rapid fluctuation of the received signal amplitude which can cause propagation impairments that affect satellite communication systems operating above 10 GHz. Scintillation data was collected in Equatorial Johor Bahru, Malaysia, based on a one-year Ku-band propagation measurement campaign, utilizing MEASAT-1 Satellite with an antenna elevation angle of 75.61°. This work concentrates on the probability density function (PDF) of diurnal variations of clear sky scintillation variance analyzed on an hourly basis. Besides, seasonal variation of scintillation amplitude has been presented in this paper. From the results, it is concluded that clear sky scintillation variance is likely to occur during morning and afternoon periods. Moreover, clear sky scintillation amplitude of the South-West monsoon shows a relatively higher comparing with others monsoon seasons. Hence, signal attenuation based on seasonal and diurnal information is of great interest for the system designers to appropriately design fade margin.Tropospheric scintillation is a rapid fluctuation of the received signal amplitude which can cause propagation impairments that affect satellite communication systems operating above 10 GHz. Scintillation data was collected in Equatorial Johor Bahru, Malaysia, based on a one-year Ku-band propagation measurement campaign, utilizing MEASAT-1 Satellite with an antenna elevation angle of 75.61°. This work concentrates on the probability density function (PDF) of diurnal variations of clear sky scintillation variance analyzed on an hourly basis. Besides, seasonal variation of scintillation amplitude has been presented in this paper. From the results, it is concluded that clear sky scintillation variance is likely to occur during morning and afternoon periods. Moreover, clear sky scintillation amplitude of the South-West monsoon shows a relatively higher comparing with others monsoon seasons. Hence, signal attenuation based on seasonal and diurnal information is of great interest for the system designers to appropriately design fade margin.

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