Prediction of Rain Attenuation at the C, X, Ku and Ka Bands for Fixed Satellite System Based on ITU-R Model in Libya (original) (raw)
Related papers
Performance analysis of rain attenuation on earth-to-satellite microwave links design in Libya
2017
Performances of earth-to-satellite microwave links operating in Ku, Ka, and V-bands are degraded by the environment and strongly attenuated by rain. Rain attenuation is the most significant consideration and challenge to design a reliable earth-to-satellite microwave links for these frequency bands. Hence, it is essential for satellite link designer to take into account rain fade margin accurately before system implementation. Rain rate is the main measured parameter to predict of rain attenuation. Rainfall statistical data measured and recorded in Libya for the period of 30 years are collected from 5 locations. The prediction methods require one minute integration time rain intensity. Therefore, collected data were analyzed and processed to convert into one–minute rain rate cumulative distribution in Libya. The model proposed by ITU-R is used to predict and investigate rain fade based on converted 1-minute rain rate data. Rain fade predicted at two locations are used for performanc...
FUOYE Journal of Engineering and Technology
The progressively demand on satellite communication systems has consequently resulted in lower frequency bands getting more congested. The usage of frequency band beyond 10 GHz is in focus nowadays as a result of the rapid expansion of radio communication systems. However, Rain is the leading attenuation factor of different communication signal of frequencies beyond 10 GHz. Attenuation due to rain has a significant propagation effect that needs to be carefully considered in satellite communication system network. Rain attenuation predictions and rain rate are essential when planning microwave satellite communication links. A review of the rain rate integration time and rain attenuation models for microwave and millimeter bands satellite system is presented. Keywords: Frequency Band, Rain Attenuation, Rain Attenuation Model, Rain Rate, Satellite System
Telecommunication Systems, 2019
Rain induced attenuation prediction is considered a fundamental step in the analysis of satellite communication links for frequencies above 10 GHz, due to their major effect on the satellite communication link and services. This paper presents an approach for predicting and analysing the satellite link performance during rainfall in subtropical climate for K and Ka frequency bands. The study characterizes the Iraqi climate as one of the subtropical regions based on the rain effects and split it into impairments related segments. Moreover, the study presents the first analysis and database for rainfall impairments in Iraq to the best of authors' knowledge along with a proposed method for direct extraction of rain-induced impairments. It is found from the results that the rain attenuation at the northern region has a higher impact than the central and the southern regions, consequently the performance of rain attenuation impairments is divided into two segments: high rain impairments segment (HRIS) in the northern region and low rain impairments segment (LRIS) (in the central and southern regions). Nevertheless, it is found that, out of 9 stations, the prediction model based on ITU and Crane estimated rainfall rates are inaccurate in 6 and 5 stations, respectively. Substantially, the results declare that the proposed method predicts the rain attenuation value based on the frequency given with RMSEs under 0.6 and 1.5 for LRIS and HRIS, respectively. This reviles the qualified accuracy of the proposed method and the frequency-dependent coefficients. Such achievements could be an appropriate preliminary design benchmark for earth-sky microwave links, and also provide a broad idea of rain attenuation and link performance for microwave engineers.
Rain attenuation distribution for satellite microwave links application in Tanzania
Indonesian Journal of Electrical Engineering and Computer Science
Rain rate and Rain Attenuation predictions are important in radio system operating at Ku and Ka bands as they affect telecommunication systems performance. To adequately estimate rain-induced attenuation and fading, the International Telecommunication Union (ITU) recommends use of rainfall data collected using 1-minute integration time. For Tanzania, no rainfall data with 1-minute integration time is available either through measurements or conversion from rainfall data with longer integration time. In this paper the rain attenuation is predicted for seven locations in the coastal area of Tanzania. The 1- minute rainfall rate is determined by Chebil’s model using long-term measurements from Tanzania Metrological Agency (TMA) collected for a period of forty years, results obtained are used to estimate rain attenuations. By using the International Telecommunication Union-Recommendation (ITU-R) model, rain attenuation is predicted at horizontal polarization at Ku and Ka band. The resul...
advantages compared to the terrestrial radio systems. However, rain can cause significant attenuation on earth-space paths. This paper will present a comparison study of rain attenuation models of satellite communication channels based on measured point rain intensity in Hungary. Results will be calculated exemplarily for locations in Hungary, Germany and Spain, where rain intensity values are available. In this paper our first results on rain attenuation modeling in satellite communication channel will be presented.
Rain Attenuation Prediction at Ku Band Using Satellite Signal Beacon Measurement in Iran
2013
In this paper satellite wave propagation at Ku and Ka band is considered. The design and simulation of a typical satellite beacon receiver at Ka band is designed and simulated for the future works. Also rain attenuation prediction at Ku band using satellite signal beacon measurement and simulations for Iran Telecommunication Research Center (ITRC) are presented. The measurement setup consists of two simultaneous measurement stations: satellite signal beacon measurement station and automatic weather measurement station. Within the period of January to June 2012, beacon signal level and rain rate were simultaneously recorded, collected and analyzed. The results of these measurement are compared with ITU- R attenuation model. The comparison shows that there are some differences between ITU-R and measured data. The main conclusion of this paper is that using global rain attenuation prediction models is not suitable solution in local satellite link design and detailed satellite wave prop...
Assessment of X-band earth-satellite link rain attenuation prediction in Malaysia
2014
Background: Predicted rain fade values for an Earth-satellite link operating at X-band frequency had been generated using the latest ITU-R Recommendation, P618-11. Rain fade values for the very same link were also estimated using the "radar-derived attenuation" technique. The radar technique involves the exploitation of vertical polarization S-band meteorological radar reflectivity information to calculate the possible rain attenuation along the satellite propagation paths. All estimated rain fade values were then compared with the actual measured signal of RazakSAT's X-band satellite transmission. The measured X-band (8 GHz) transmission signals were collected and analyzed at the Malaysian National Space Agency (NSA) space center. Objective: Preliminary findings concerning the feasibility of each estimation technique are presented in this paper. The research also attempts to investigate the validity of the mentioned rain attenuation estimation techniques. Results: Preliminary findings concerning the feasibility of each estimation technique are presented in this paper. The research also attempts to investigate the validity of the mentioned rain attenuation estimation techniques. Conclusion: Such knowledge can be considered critical for the design of reliable Earth-Space communication link and certainly can be used in the preliminary proposition plan for the link designers as well as engineers.
IEEE Access
The Ka-band is modifying the mode of legacy communication towards versatile satellite-oriented systems with the beam-spot capability and a high-throughput architecture to provide twice the capability of classic Fixed Satellite Service (FSS) satellites, thus significantly reducing the cost per bit. Given this background, the contribution of precipitation rate and Ka-band downpour attenuation are expected to improve statistical models for effect prediction. The International Telecommunication Union (ITU) and local researchers are working tirelessly to determine the best prediction model for tropical climates. However, persistent and continuous efforts are required because currently available models do not perform well. The current prediction model for large datasets exhibits a certain deviation. Direct beacon measurement has been compared with an available prediction model that analyses rain effects in tropical regions. Theoretically, the size of the antenna and its gain influence the performance of the receiving signal. Size and availability are two factors which cause degradation and outage in the receiving signal. The majority of extant studies focus on a single antenna with a diameter lesser than 2.4m. Theoretically, antennas with a smaller diameter possess a smaller margin in comparison with antennas with larger diameters. This condition could affect the prediction model when the high attenuation causes a rapid outage in a small antenna and lead to the unavailability of measurement results. To study such effects and provide a good recommendation, the current work measures the beacon attenuation data at two locations, namely, Bukit Jalil (Kuala Lumpur) and Cyberjaya (Selangor). The locations are approximately 15 km apart and have antennas from 0.65m to 31.1m in sizes. Analyses using an available prediction model revealed that ITU-R P.618 provides the lowest RMS value of 14.37 with regards to rainfall rate on two selected samples in Malaysia. High-accuracy prediction can be achieved through the contribution of this study, and comparative data can be obtained for future research. This study is an encouraging step towards a highly comprehensive and accurate prediction of tropospheric impairments in Ka-band satellite communications in the tropical region. ⁞ INDEX TERMS ITU, Rain attenuation, Ka-band satellite communication.
Estimation of the Long-Term Propagation Losses Due To Rain On Microwave Satellite
FUPRE Journal of scientific and industrial research, 2018
This paper presents the estimation of long term propagation losses due to rain on microwave satellite links over Jos. Data were retrieved from the National Space Research and Development Agency (NASRDA) Abuja, Nigeria. The data collected was rainfall rate (mm/h) for theperiod of three year (2015-2017) over Jos. Results were obtained based on the exceedance distribution frequency of percentage time (%) and cumulative distribution of one-minute rain rate which revealed that higher rainfall rate (above 100 mm/hr) account for about 0.01 and 0.001% time ofexceedance and it is during such times that maximum propagation losses due to rainfall is significant and can be best estimated.
european conference on antennas and propagation, 2012
This paper examined the use of existing empirical rain attenuation models for earth-space paths links for frequencies at Q band and greater. Extrapolation of these models that are based on low frequency (< 20 GHz) data results in significant spread in attenuation predictions at 50 GHz and higher. Extrapolation of models based on the p = 0.01% rainfall rate to higher frequencies is limited due to the power law dependence of rain attenuation. Models that use the full rainfall rate to map attenuation to the corresponding rainfall rate distribution are subject to inaccuracies due to the artificial mapping of all sources of attenuation to a single rainfall rate. Comparison of the ITU-R P.618 attenuation model to available Q/V band data suggests limitations on the useful frequency range and highlights the importance of attenuation combining methodology.