Severe Cause of Cloud Attenuation and Rain Attenuation on Space Communication Link at Millimetre Band and Differentiation between Rain Attenuation and Cloud Attenuation

Author(s):  
Kandala Kalyana Srinivas ◽  
Teppala Venkata Ramana
2021 ◽  
Vol 1971 (1) ◽  
pp. 012073
Author(s):  
Langtao Bai ◽  
Zhongbo Zhu ◽  
Xiaojun Li

Author(s):  
Islam Md. Rafiqul ◽  
Ali Kadhim Lwas ◽  
Mohamed Hadi Habaebi ◽  
Md Moktarul Alam ◽  
Jalel Chebil ◽  
...  

<p><span>This paper reports a study on mitigation of propagation impairments on Earth–space communication links. The study uses time diversity as a technique for mitigating rain propagation impairment in order to rectify rain fade. Rain attenuation time series along earth-to-satellite link were measured for two years period at 12.255 GHz in Malaysia. The time diversity technique was applied on measured rain fade to investigate the level of possible improvement in system. Time diversity gain from measured one-minute rain attenuation for two years period was estimated and significant improvement was observed with different delays of time. These findings will be utilized as a useful tool for link designers to apply time diversity as a rain fade mitigation technique in Earth-satellite communications systems.</span></p>


Author(s):  
Felix Obite ◽  
Jafri Din ◽  
Kamaludin Mohammad Yusof ◽  
Basliza M. Noor

<p>In the last few years, High Altitude Platforms (HAPs) have attracted considerable effort due to their ability to exploit the advantages of satellite and terrestrial-based systems. Rain attenuation is the most dominant atmospheric impairment, especially at such frequency band. This paper addresses the modelling of rain attenuation and describes a propagation channel model for HAPs at Ka-band to provide efficient and robust wireless access for tropical regions. The attenuation due to rain is modeled based on three years measured data for Johor Bahru to estimate the actual effect of rain on signals at Ka band. The radio propagation channel is usually characterized as a random multipath channel. Specifically, a statistical derivation of probability distribution function for Rayleigh and Rician fading channels are presented. The model consists of multiple path scattering effects, time dispersion, and Doppler shifts acting on the HAPs communication link. Simulation results represent the fading signal level variations. Results show perfect agreement between simulation and theoretical, thereby conforming to the multipath structures. The information obtained will be useful to system engineers for HAPs link budget analysis in order to obtain the required fade margin for optimal system performance in tropical regions.</p>


2014 ◽  
Vol 666 ◽  
pp. 317-321
Author(s):  
Stephen Kotiang ◽  
Jae Ho Choi

Rain attenuation is one of the impairments on the performance of optical wireless communication systems, and an accurate estimation of optical extinction coefficient due to rain in an area is an important factor for setting up a reliable communication link. In this paper, a relationship between optical signal attenuation and rain intensity is derived based on the moment of method of raindrop size distribution using a three-parameter gamma model. Finally, analyticalresultsarecompared to those ofthe ITU-R model.


MAUSAM ◽  
2021 ◽  
Vol 68 (4) ◽  
pp. 621-632
Author(s):  
MEHRAN BEHJATI ◽  
JIT SINGH MANDEEP ◽  
MAHAMOD ISMAIL ◽  
ROSDIADEE NORDIN

Rainfall is a major destructive factor which severely reduces the quality and reliability of propagated signals in satellite communications. Hence, rain-attenuation prediction plays a vital role in the satellite radio link planning and engineering. The accuracy of the rain-attenuation prediction models depends on two things; (i) the accuracy of rain-rate information and (ii) the area of study. Therefore, selecting an appropriate rain-attenuation prediction model for a new site without having any specific prediction model and experimental measured rain-rate would be challenging. In this regard, this letter takes advantage of climatology skills to find an accurate model for such kind of areas. To do so, we study the Urmia-site (37.55° N, 45.1° E) and its communication link with the Eutelsat 25A (25.5° E), where there is no available experimental measured data and specific prediction models for that site. Therefore, based on the meteorological skills, the Yong-in site in South-Korea (37.43° N, 126.93° E) was chosen, as a homogeneous area with Urmia, which has available measured data of rainfall and rain-attenuation. Afterward, the most common used global prediction models are applied to Yong-in and the results are compared with the existing measurements. Consequently, the more accurate rain-rate and rain-attenuation prediction models are investigated and generalized to Urmia, which are the ITU-R P.837-5 model with 34% r.m.s. and the Joo-Hwan model with 18% r.m.s., respectively. Finally, the amount of rain-attenuation in different useful frequency bands (10-50 GHz) is investigated for Urmia by the Joo-Hwan model.


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