Observed correlation between frequency exponent and elevation angle of tropospheric scintillation

2003 ◽  
Author(s):  
A. Savvaris
Keyword(s):  
Elevation Angle ◽  
Frequency Exponent ◽  
Tropospheric Scintillation

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.

Tropospheric scintillation prediction models for a high elevation angle based on measured data from a tropical region

2013 ◽  
Vol 105-106 ◽  
pp. 91-96 ◽  
Author(s):  
Nadirah Binti Abdul Rahim ◽  
Md. Rafiqul Islam ◽  
Mandeep J.S. ◽  
Hassan Dao ◽  
Saad Osman Bashir
Keyword(s):  
Prediction Models ◽  
Elevation Angle ◽  
High Elevation ◽  
Measured Data ◽  
Tropical Region ◽  
Tropospheric Scintillation

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 Study of tropospheric scintillation effects in Ku-band frequency for satellite communication system

2020 ◽  
Vol 10 (3) ◽  
pp. 3136
Author(s):  
Nadirah Abdul Rahim ◽  
Hanis Nabilah A. Mulop ◽  
Khairayu Badron
Keyword(s):  
Electromagnetic Waves ◽  
Satellite Communication ◽  
Elevation Angle ◽  
Small Scale ◽  
Band Frequency ◽  
Clear Sky ◽  
Tropospheric Scintillation ◽  
Sky Conditions ◽  
Beacon Signal ◽  
Ku Band

Scintillation is a rapid fluctuation of an electromagnetic waves in terms of phase and amplitude due to a small-scale inconsistency in the transmission path (or paths) with time. Scintillation exists continuously throughout a day whether during raining or clear sky conditions. The raw signal data need to exclude other propagations factors that include signal fluctuations to further understand the scintillation studies. This paper presents the analysis of tropospheric scintillation data from January 2016 till December 2016 at Ku-band frequency of 12.202 GHz beacon signal. The experimental data from MEASAT 3B were collected and analyzed to see the effect of tropospheric scintillation. The elevation angle of the dish antenna is 77.45o. The highlighted objectives are to analyze the scintillation data at Ku-band, and to compare and validate the results with other scintillation models. The result shows that the stipulated scintillation analysis has higher amplitude, which is 0.73 dB compared to other scintillation analysis which has lower scintillation amplitude: 0.45 dB (Karasawa), 0.42 dB (ITU-R), 0.4 dB (Nadirah & Rafiqul), 0.42 dB (Van De Kamp) and 0.11 dB (Anthony & Mandeep).

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.

The elevation angle of the vagina (EAV) following different pelvic reconstructive procedures

2018 ◽  
Author(s):  
J Neymeyer ◽  
AY Weintraub ◽  
S Weinberger ◽  
DE Moldovan ◽  
K Kornienko ◽  
...  
Keyword(s):  
Elevation Angle ◽  
Reconstructive Procedures

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 Spectral albedo of coastal landfast sea ice in Prydz Bay, Antarctica

2020 ◽  
pp. 1-11
Author(s):  
Guanghua Hao ◽  
Roberta Pirazzini ◽  
Qinghua Yang ◽  
Zhongxiang Tian ◽  
Changwei Liu
Keyword(s):  
Sea Ice ◽  
Near Infrared ◽  
Elevation Angle ◽  
Early Summer ◽  
Prydz Bay ◽  
Katabatic Wind ◽  
Surface Conditions ◽  
Zhongshan Station ◽  
Landfast Sea Ice ◽  
Two Phases

Abstract The surface spectral albedo was measured over coastal landfast sea ice in Prydz Bay (off Zhongshan Station), East Antarctica from 5 October to 26 November of 2016. The mean albedo decreased from late-spring to early-summer, mainly responding to the change in surface conditions from dry (phase I) to wet (phase II). The evolution of the albedo was strongly influenced by the surface conditions, with alternation of frequent snowfall events and katabatic wind that induce snow blowing at the surface. The two phases and day-to-day albedo variability were more pronounced in the near-infrared albedo wavelengths than in the visible ones, as the near-infrared photons are more sensitive to snow metamorphism, and to changes in the uppermost millimeters and water content of the surface. The albedo diurnal cycle during clear sky conditions was asymmetric with respect to noon, decreasing from morning to evening over full and patchy snow cover, and decreasing more rapidly in the morning over bare ice. We conclude that snow and ice metamorphism and surface melting dominated over the solar elevation angle dependency in shaping the albedo evolution. However, we realize that more detailed surface observations are needed to clarify and quantify the role of the various surface processes.

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