scholarly journals On the conversion of a 3-hour integration time rain rate into one minute rain rate for forecast of attenuation due to rain

2021 ◽  
Vol 2034 (1) ◽  
pp. 012001
Author(s):  
M A Sodunke ◽  
J S Ojo ◽  
Arijit De ◽  
O A Sojobi
Keyword(s):  
2008 ◽  
Vol 8 (2) ◽  
pp. 84-89 ◽  
Author(s):  
Myoung-Won Jung ◽  
Il-Tak Han ◽  
Moon-Young Choi ◽  
Joo-Hwan Lee ◽  
Jeong-Ki Pack

Author(s):  
Islam Md Rafiqul ◽  
Md Moktarul Alam ◽  
Ali Kodhim Lwas ◽  
Sarah Yasmin Mohamad

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.


2021 ◽  
Vol 6 (2) ◽  
pp. 27-37
Author(s):  
Abayomi Isiaka O. Yussuff ◽  
◽  
Kabir Momoh ◽  

This work concerns the evaluation of the performances of some selected rain attenuation models at two different locations in Lagos, Nigeria at 12 and 40 GHz. Scarcity of rainfall data in the tropical regions resulted in abysmal research efforts into the causes and solutions to satellite signal outages, this was further exacerbated by the convective tropical rain precipitations. The globally adopted ITU-R model, had been declared unsuitable for predicting rain attenuation in the tropics by several researchers in the literature. Two-year (January 2016 to December 2017) local rainfall data were sourced from the Nigerian Meteorological Services (NIMET) for two coastal stations (Ikeja and Oshodi). Rain attenuation exceeded for rain rate at 0.01% of the time, was computed after the 1-hour rain rate integration time which was sourced from NIMET was converted to 1-minute integration time. Attenuation exceeded for other percentages of time were also obtained using statistical interpolation and extrapolation methods. The collected data were tested with ITU-R, SST, SAM, DAH and Silva Mello et al. For Ikeja at 12 GHz, the SST was observed to closely match the measurement attenuation at 0.01%≤p≤1% of time exceeded; closely followed by Silver Mello. For Oshodi also at 12 GHz, SST intersected with the measured attenuation at 0.01%≤p≤0.03%, and p=0.1% of time. However, at 40 GHz, all the prediction models performed poorly by underestimating the measurement for Ikeja, although SST showed the best effort. The SST model matched the measurement, especially at p=0.03% and p=0.5% for Oshodi at 40 GHz, closely followed by Silva Mello which matched the measurement at p=0.05% and p=0.1%, while ITU-R, SAM and DAH largely underestimated the measurement. The SST was therefore affirmed the overall best performed rain attenuation prediction model for both stations at both frequency bands; closely followed by the Silva Mello. ITU-R, SAM and DAH on the other hand performed poorly. The findings arising from this work could present useful information to satellite equipment designers and manufacturers, while at the same time ensuring that service providers conform to the required service level agreements


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 ◽  
...  

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


Author(s):  
Ajewole , M. O. ◽  
Owolawi , P. A. ◽  
Adetunji , R. M.

Notice of Retraction-----------------------------------------------------------------------After careful and considered review of the content of this paper by a duly constituted expert committee, this paper has been found to be in violation of APTIKOM's Publication Principles.We hereby retract the content of this paper. Reasonable effort should be made to remove all past references to this paper.The presenting author of this paper has the option to appeal this decision by contacting ij.aptikom@gmail.com.-----------------------------------------------------------------------  Launching into the next generation of wireless communication network (5G network) requires secure high data rate, high speed and huge bandwidth links. With the tremendous increase in broadband users, the existing communication systems such as radio frequency (RF) and microwave links cannot meet up with the challenges due to their link interference and low bandwidth. A current technology that promises such requirements and more is Free Space Optical (FSO) communication. The FSO basically involves the transmission of signal-modulated optical radiation from a transmitter to a receiver through the atmosphere or outer space. It is designed to complement the traditional fibre optical communication links. However, location-variant atmospheric channel degrades the quality and performance of an FSO system under severe atmospheric conditions. This paper attempts to assess both fog- and rain-induced attenuation on the performance of FSO link in a terrestrial terrain using measured visibility and rain rate data at Akure, Nigeria. 5-year (2012-2016) archived visibility data and measured rain rate data of 1-minute integration time obtained from Nigerian Meteorological Agency (NIMET) and the Department of Physics, Federal University of Technology, Akure respectively, were used to compute the fog- and rain-induced specific attenuations using Kruse and Carboneur models. The performance of the FSO system was analyzed through link margin by using the parameters of a commercial optical transceiver, Terescope 5000. Findings from this work will be useful for FSO system design in the area.


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