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IJRSP Vol.41 [2012] >
IJRSP Vol.41(4) [August 2012] >
| Title: | Sensitivity of Z-R relations and spatial variability of error in a Doppler Weather Radar measured rain intensity |
| Authors: | Dutta, Devajyoti
Sharma, Sanjay
Kannan, B A M
Venketswarlu, S
Gairola, R M
Rao, T N
Viswanathan, G |
| Keywords: | Radar reflectivity factor
Rain drop size distribution
Rain intensity
Tipping bucket rain gauge
Z‒R relation sensitivity |
| Issue Date: | Aug-2012 |
| Publisher: | NISCAIR-CSIR, India |
| PACS No.: | 92.40.eg; 92.60.jf |
| Abstract: | A study is carried out to investigate the sensitivity of Z-R
relations and spatial variability of error in a Doppler Weather Radar (DWR)
measured rain intensity. For this purpose, observations from a DWR at Satish
Dhawan Space Centre, SHAR (13.66°N, 80.23°E) and five units of automatic
tipping bucket rain gauges around the DWR are utilized. It is found that rain with intensity > 20 mm h-1 occurs for
16% of the total rain time but its contribution is 53% to the total rainfall. Sensitivity
of Z-R relations are examined with the help of Z‒R relations developed by two
different approaches. One set of relations are developed from Joss Waldvogel
Disdrometer (JWD) observations of rain drop size distribution (ZJWD‒RJWD
) and other set of relations are developed with the help of combined use
of DWR and rain gauge observations (ZDWR‒RRG). Performance
of the DWR is improved with ZDWR‒RRG relation. Using ZDWR‒RRG
relations for Z ≤
30 dBZ and Z > 30 dBZ, the root mean square error (rmse) and bias for DWR
measured rain intensity is reduced by 28% & 39% and 33% & 74%,
respectively. The bias and error between DWR and rain gauge measured rain
intensity are found to decrease with respect to decrease in distance between
the rain gauges and DWR.
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| Page(s): | 448-460 |
| CC License: |  CC Attribution-Noncommercial-No Derivative Works 2.5 India |
| ISSN: | 0975-105X (Online); 0367-8393 (Print) |
| Source: | IJRSP Vol.41(4) [August 2012]
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