scholarly journals Modification of ITU-R Rain Fade Slope Prediction Model Based on Satellite Data Measured at High Elevation Angle

2012 ◽  
Vol 12 (5) ◽  
Author(s):  
Hassan Dao ◽  
Md. Rafiqul Islam ◽  
Khalid Al-Khateeb
Keyword(s):  
Prediction Model ◽  
Elevation Angle ◽  
Heavy Rain ◽  
High Elevation ◽  
Time Interval ◽  
Kuala Lumpur ◽  
Tropical Regions ◽  
Mitigation Techniques ◽  
One Year ◽  
Ku Band

Rain fade slope is one of fade dynamics behaviour used by system engineers to design fade mitigation techniques (FMT) for space-earth microwave links. Recent measurements found that fade slope prediction model proposed by ITU-R is unable to predict fade slope distribution accurately in tropical regions. Rain fade measurement was conducted  in Kuala Lumpur (3.3° N, 101.7° E) where located in heavy rain zone by receiving signal at 10.982 GHz (Ku-band) from MEASAT3 (91.5° E) on 77.4° elevation angle. The measurement has been carried out for one year period. Fade slope S parameter on ITU-R prediction model has been investigated. New parameter is proposed for the fade slope prediction modeling based on measured data at high elevation angle, Ku-band. ABSTRAK: Cerun hujan pudar adalah salah satu dinamik tingkah laku pudar yang digunakan oleh jurutera sistem untuk mereka bentuk teknik-teknik pengurangan pudar (FMT) bagi link gelombang mikro ruang bumi. Ukuran baru-baru ini mendapati bahawa cerun pudar ramalan model yang dicadangkan oleh ITU-R tidak mampu untuk meramalkan pengagihan cerun pudar tepat di kawasan tropika. Pengukuran  hujan pudar telah dijalankan di Kuala Lumpur (3.3° N, 101.7° E) yang terletak di kawasan hujan lebat dengan menerima isyarat pada 10,982 GHz (Ku-band) dari MEASAT3 (91.5° E) pada sudut ketinggian 77.4°. Pengukuran telah dijalankan untuk tempoh satu tahun. Parameter cerun pudar S pada model ramalan ITU-R telah disiasat. Parameter baru adalah dicadangkan untuk pemodelan cerun pudar ramalan berdasarkan data yang diukur pada sudut paras ketinggian, Ku-band.KEYWORDS: fade slope; ITU-R; fade mitigation techniques; sampling time interval

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.

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.

scholarly journals 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.

scholarly journals Prediction of PM2.5 Purification Time of Air Purifier under High Elevation Angle and High Wind Speed

2021 ◽  
Vol 257 ◽  
pp. 01081
Author(s):  
WuFeng Jin ◽  
Cheng Wang ◽  
Chong Shi ◽  
Zhiqiang Wang
Keyword(s):  
Prediction Model ◽  
Elevation Angle ◽  
Influence Factors ◽  
High Elevation ◽  
Linear Regression Method ◽  
Simulation Research ◽  
Multiple Linear Regression Method ◽  
Purification Time ◽  
Air Purifier ◽  
The Relationship

In order to achieve the best purification effect of PM2.5 at different personnel positions, it is necessary to study the PM2.5 purification time at different personnel positions in the room when the influence factors change, and establish a prediction model of the purification time.In this paper, air purifier and room models were established for simulation research. Purification time of air purifier at different locations in the room was taken as regression data, and multiple linear regression method was adopted to obtain the relationship between each impact factor and PM2.5 purification time, and a prediction model of PM2.5 purification time at different personnel locations in the room was proposed.The results of this study provide a theoretical basis for putting forward the whole intelligent scheme of air purifier.

scholarly journals Characterization of concurrent ku band tropospheric scintillation and rain attenuation in Malaysia

2019 ◽  
Vol 15 (2) ◽  
pp. 956
Author(s):  
Ibtihal Fawzi Elshami ◽  
Jafri Din ◽  
Lam Hong Yin ◽  
Ali I Elgayar
Keyword(s):  
Communication Systems ◽  
Satellite Communication ◽  
Power Spectral Analysis ◽  
Rain Attenuation ◽  
Significant Information ◽  
Tropical Regions ◽  
Significant Impairment ◽  
One Year ◽  
Tropospheric Scintillation ◽  
Ku Band

<span>Tropospheric scintillation in satellite communication systems operating at frequencies over 10 GHz is a significant impairment, especially in tropical regions, as attenuation affects scintillation dramatically. This work concentrates on tropospheric scintillation in equatorial Johor Bahru, Malaysia, based on a one-year Ku-band propagation measurement study utilising a direct broadcast receiver and an automatic weather station. This study aimed to investigate the relationship between wet scintillation and rain attenuation using experimental measurements. The power spectral analysis has been carried out to determine required cut-off frequency of filtering to separate out rain attenuation and scintillation effects. The results can provide significant information on the fluctuations of wet scintillation at Ku-band earth space link in tropical regions.</span>

scholarly journals Accuracy of Doppler Determinations of Station Positions

1972 ◽  
Vol 48 ◽  
pp. 101-103
Author(s):  
R. J. Anderle
Keyword(s):  
Elevation Angle ◽  
High Elevation ◽  
Time Of Day ◽  
Satellite Observations ◽  
Standard Errors ◽  
Lower Elevation ◽  
Self Consistent

Locations of Doppler satellite observing stations have been revised to obtain a set which is more self-consistent and more consistent with the CIO pole. Residuals of satellite observations for 1970 have been analyzed using the new coordinates to determine mean and standard errors for five days of observations of latitude versus station, time of day, and elevation angle. The accuracy of the determination of latitude is about 4 meters at moderate and high elevation angles. But since more satellite passes occur at lower elevation angles, the accuracy of determination of a component of position based on five days of observation of one satellite is only about 2 meters.

scholarly journals Development of Heavy Rain Damage Prediction Model Using Machine Learning Based on Big Data

2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Changhyun Choi ◽  
Jeonghwan Kim ◽  
Jongsung Kim ◽  
Donghyun Kim ◽  
Younghye Bae ◽  
...  
Keyword(s):  
Machine Learning ◽  
Big Data ◽  
Prediction Model ◽  
Prediction Models ◽  
Meteorological Data ◽  
Heavy Rain ◽  
Machine Learning Techniques ◽  
Damage Prediction ◽  
Explanatory Variables ◽  
The Republic

Prediction models of heavy rain damage using machine learning based on big data were developed for the Seoul Capital Area in the Republic of Korea. We used data on the occurrence of heavy rain damage from 1994 to 2015 as dependent variables and weather big data as explanatory variables. The model was developed by applying machine learning techniques such as decision trees, bagging, random forests, and boosting. As a result of evaluating the prediction performance of each model, the AUC value of the boosting model using meteorological data from the past 1 to 4 days was the highest at 95.87% and was selected as the final model. By using the prediction model developed in this study to predict the occurrence of heavy rain damage for each administrative region, we can greatly reduce the damage through proactive disaster management.

One-Year All-Cause Mortality After Stroke: A Prediction Model

PM&R ◽  
2013 ◽  
Vol 6 (6) ◽  
pp. 473-483 ◽  
Author(s):  
Barbara E. Bates ◽  
Dawei Xie ◽  
Pui L. Kwong ◽  
Jibby E. Kurichi ◽  
Diane Cowper Ripley ◽  
...  
Keyword(s):  
Prediction Model ◽  
All Cause Mortality ◽  
One Year
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