Calculation of rain attenuation for higher frequency
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Transcript of Calculation of rain attenuation for higher frequency
Calculation of Rain Attenuation For Higher Frequencies
Under The Guidance ofDr. K. Sarat Kumar
Professor
[email protected](M.Tech) -K L University
Presenter: Kailash Karki 152040006
Introduction
• Attenuation implies decrease in signal amplitude.
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Statement of Problem
Why higher frequency band??
Why we need to study rain attenuation ??
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Assumptions
o Shape of raindrops is spherical.
o As the wave propagates through the volume of rain ,its intensity decays.
o Each drops contributions are independent of the other drops and each contibution is additive.
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Terminology Used:
• Specific Attenuation
• Exceedance Probability
• Slant Path Length
• Horizontal Reduction Factor
• Vertical Adjustment Factor
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Prediction of Rain Attenuation
ITU-R Model
Rain Attenuation(db) = Specific attenuation * Effective path length
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Specific Attenuation is obtained from the rain rate(mm/h) using the power law relationship A(dB/km) = K* Rα
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Effective Path Length
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Calculate Slant Path Length
Horizontal Projection
Horizontal Reduction Factor
Vertical Adjustment Factor
Effective Path Length = Horizontal Projection * Vertical Adjustment Factor
Used Parameters
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Parameters Value
Rain Rate 58.43 mm/hr
Elevation Angle 43 (degree)
Latitude of Earth Station 17.20 (degree)
Rain Height 4.698 Km
Simulation Results
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Fig: Regression Coefficient, K Vs Frequency
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Fig: Regression Coefficient, K Vs Frequency
Contn..
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Fig: Specific Attenuation Vs Frequency
Contn..
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Fig: Effective Path Length Vs Frequency
Contn..
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Fig: Total Attenuation Vs Frequency
Contn..
15Fig: Attenuation For Different Exceedance Probability
Conclusion
• At high frequency the effect of rain is severe.
• For twenty four hours signal availability effective rain fade mitigation techniques should be implemented.
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