Analysis of Rainfall Attenuation Using Oblate Raindrops

2002 ◽  
pp. 227-244
Keyword(s):  
Rainfall Attenuation

Rainfall Attenuation Measurement at Ota, a Tropical Location

2019 ◽  
Author(s):  
Ometan Oluwafunmilayo Oluwayemisil ◽  
Omotosho Temidayo Victor ◽  
Adewusi Oladimeji Mustapha ◽  
Akinwumi Sayo Akinloye ◽  
Emetere Moses Eterigho ◽  
...  
Keyword(s):  
Attenuation Measurement ◽  
Rainfall Attenuation ◽  
Tropical Location

scholarly journals Prediction of Rain Attenuation and Impact of Rain in Wave Propagation at Microwave Frequency for Tropical Region (Uttarakhand, India)

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Mukesh Chandra Kestwal ◽  
Sumit Joshi ◽  
Lalit Singh Garia
Keyword(s):  
Microwave Frequency ◽  
Exponential Model ◽  
Rain Attenuation ◽  
Tropical Region ◽  
Site Visit ◽  
Classical Approach ◽  
Atmospheric Attenuation ◽  
Tropical Regions ◽  
Attenuation Level ◽  
Rainfall Attenuation

The most classical approach of determining rain attenuation for radio-wave frequency has been to theoretically determine the specific attenuation. At frequency over 10 GHz, rain and precipitation can influence the attenuation a lot; the effect of atmospheric attenuation between the source and destination over wireless communication is of major concern and a proper site visit and proper method are required to control the attenuation level so that the performance can be increased. In this paper exponential model has been used to determine the attenuation level for k-region (India) which can be used for region having similar condition. The analyzed predicted attenuation data have been compared with ITU-R measured rain attenuation, and the results will provide useful estimation of rainfall attenuation on microwave links in tropical regions that have similar conditions as (Almora) Uttarakhand region.

Comparison of measured rain attenuation and ITU-R predictions on experimental microwave links in Malaysia

2011 ◽  
Vol 3 (4) ◽  
pp. 477-483 ◽  
Author(s):  
Amuda Yusuf Abdulrahman ◽  
Tharek bin Abdulrahman ◽  
Sharul Kamal bin Abdulrahim ◽  
Ulaganathen Kesavan
Keyword(s):  
Cumulative Distribution Function ◽  
Rain Rate ◽  
Rain Attenuation ◽  
Rain Gauge ◽  
Cumulative Distribution ◽  
Rain Gauge Data ◽  
Tropical Regions ◽  
International Telecommunication ◽  
Rain Rates ◽  
Rainfall Attenuation

This paper presents the results of direct rain attenuation measurements carried out on four experimental microwave links, installed at UTM, Malaysia. The links operate at frequencies of 15, 22, 26, and 38 GHz and the cumulative distribution function for different rain rates have been generated from the measured 4-year rain gauge data. The experimentally measured attenuation data have been compared with International Telecommunication Unior-R rain attenuation predictions; and it has been found that the latter have underestimated the measured values, especially at higher rain rates. The deviations have been modeled as a function of rain rate exceedances R%p. It is hoped that the study will provide useful information for estimation of rainfall attenuation on microwave links in tropical regions that have similar situation to Malaysia.

scholarly journals 60- to 1-Min Rainfall-Rate Conversion: Comparison of Existing Prediction Methods with Data Obtained in the Southeast Asia Region

2008 ◽  
Vol 47 (3) ◽  
pp. 925-930 ◽  
Author(s):  
J. S. Mandeep ◽  
S. I. S. Hassan
Keyword(s):  
Southeast Asia ◽  
Rain Gauge ◽  
Rainfall Rate ◽  
Data Conversion ◽  
Integration Time ◽  
Prediction Methods ◽  
Rate Data ◽  
Rate Conversion ◽  
Effective Integration ◽  
Rainfall Attenuation

Abstract Rainfall-rate statistics are frequently derived on the basis of rain gauge recordings with effective integration times of 10 min or longer. The conversion of such data to equivalent statistics for an effective integration time of 1 min is very important to predict rainfall attenuation at a location accurately. Because of the limited availability of 1-min rainfall-rate data, conversion of available rainfall-rate distributions with longer integration times to the desired 1-min distributions is needed. Several methods for converting 60-min rainfall rates to 1-min rainfall rates are tested against measured rainfall rates from tropical, high-rainfall-rate regions. Segal’s method was found to perform the best overall when compared with other conversion methods.

scholarly journals Analytical Approach to Critical Diameters in Raindrop Size Distribution in Durban, South Africa

2018 ◽  
pp. 1-8
Author(s):  
Oluwumi Adetan ◽  
Olumuyiwa Oludare Fagbohun
Keyword(s):  
South Africa ◽  
Size Distribution ◽  
Analytical Approach ◽  
Area Under The Curve ◽  
Rain Attenuation ◽  
Budget Analysis ◽  
Raindrop Size Distribution ◽  
Link Budget ◽  
Raindrop Size ◽  
Rainfall Attenuation

Adequate information of the raindrop size distribution is very significant for the prediction and evaluation of attenuation signal due to rain. In this study, an analytical approach is adopted to determine the peak diameter  where the specific rain attenuation is maxima in Durban (29º52'S, 30º58'E), South Africa; using the spherical raindrop shape at temperature T = 20ºC. The overall rainfall attenuation is computed by integrating over all the drop sizes and determine the differential change in the attenuation as observed over a fixed diameter interval, (= 0.1 mm). The critical diameters are the range of diameters where the rain attenuation is highly predominant, which constitutes the surface area under the curve and along the abscissa regions. The critical diameters are seen to coalesce around the peak diameter, at which the maximum attenuation occurs. The maximum specific rain attenuation peaks at the diameter It was observed that the peak diameter is frequency dependent while the parameters, µ, the mean and σ the standard deviation which determines the width of the distribution are found to be region-dependent. The peak attenuation for the stratiform rainfall type varies between 0.8 ≤ D ≤ 1.5 mm whereas for the convective rainfall, the specific rain attenuation peaks between 1.4 ≤ D ≤ 2.7 mm at all frequencies. A proper knowledge of the rainfall attenuation characteristics is useful for proper planning and for the purpose of link budget analysis by operators in this particular region.

scholarly journals Kajian Impelementasi Quality Control Faktor Bright Band dan Atenuasi Radar Cuaca C-Band

2021 ◽  
Vol 9 (1) ◽  
pp. 111-120
Author(s):  
Deffi M Putri ◽  
◽  
Eko Yulianto Nugroho ◽  
Januar Rahmad Pratama ◽  
◽  
...  
Keyword(s):  
Quality Control ◽  
Attenuation Correction ◽  
Daily Rainfall ◽  
Freezing Level ◽  
Bright Band ◽  
Weather Radars ◽  
Hourly Rainfall ◽  
Product Image ◽  
Rainfall Attenuation

Weather radars have several limitations there are bright band echoes and attenuation of electromagnetic wave from radar’s beam. The purpose of this research is to conduct an analysis respect to the result of quality control from both of the limitations in 2019 which divide into four case study. Freezing level height of radiosonde used for support the identification activity of BBC phenomena. The result of BBC can reduce the BBE patterns however, it unable to function optimally in reducing all parts of the BBE patterns. Rainfall attenuation correction that have been done shows various results, either quantitatively or qualitatively. Attenuation correction is able to increase the rainfall value in product image SRI and PAC qualitatively. Quantitative analysis shows that the r and MAE values after attenuation correction of hourly rainfall have a good value besides that the attenuation correction in daily rainfall data is able to improve the estimate by 62.5%.

Sign in / Sign up

Export Citation Format

Share Document