기상레이더 강수추정 개선을 위한 오차보정방법 평가
Evaluation of Bias Correction Methods for Improving Weather Radar-based Rainfall Estimation
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초록
기상레이더를 이용한 강수추정에는 오차가 발생할 수 있는 가능성이 매우 많다. 본 연구에서는 전반적인 기상레이더 강수추정 과정에서 발생할 수 있는 반사도 관측 오차(Z-bias)와 강수오차(R-bias)에초점을 맞추었다. Z-bias 보정을 위해, 반사도, 차등반사도, 비차등위상차를 이용하는 자기상관관계방법을 적용하였다. R-bias 보정을 위해서는 Mean Field Bias Cocrrection (MFBD)와 Local Gauge Correction (LGC) 방법의 두 가지 후처리방법을 이용하였다. Z-bias와 R-bais 오차보정방법들을 Radar- AWS Rainrate 모형에 적용하였다. 18개 강수사례에서 Z-bias 오차보정결과의 RMSE(7.37 → 7.21 mm/hr)와 상관계수(0.83 → 0.84)가 향상되었다. 강수형태에서는 장마와 지역강수발생에서 더 개선되었다. Z-bias와 R-bias 오차보정 적용결과에서 LGC 방법이 MFBC 방법보다 RMSE: 63.7%, 상관계수: 11.7% 더 정확성이 우수하였으며, 이는 LGC 방법이 각 격자마다 보정이 가능하기 때문으로판단된다.
Abstract
This study focused on the reflectivity measurement bias (Z-bias) and the rainfall bias (R-bias) in the radar-rainfall estimation process. To correct the Z-bias, the self-consistency constraint method using reflectivity, differential reflectivity, and specific differential phase was carried out. Then, the Mean Field Bias Correction (MFBC) method and the Local Gauge Correction (LGC) method, were conducted to correct the R-bias. All of correction methods were applied to the Radar-AWS Rainrate model to calculate radar-rainfall estimates. The accuracy of the Z-bias correction method in 18 rainfall cases was improved by considering the RMSE (from 7.37 to 7.21 mm/hr) and the Correlation Coefficient (CC) (from 0.83 to 0.84) on average. The accuracy of results in the Changma and local torrential cases was improved by applying the Z-bias correction. The accuracy obtained by the LGC method (by 63.7% in RMSE and 11.7% in CC compared to MFBC) was superior to the MFBC method results because, in the LGC method, different R-biases were applied to each rainfall estimates in each radar pixel.
참고문헌 (30)
- Anagnostou, E. N., "Mean-field Rainfall Bias Studies for WSR-88D", Journal of Hydrologic Engineering, 3, pp.149~159 (1998)
- Austin, P. M, "Relation between Measured Radar Reflectivity and Surface Rainfall", Monthly Weather Review, 115, pp.1053~1070 (1987)
- Campos, E., "Instrumental Uncertainties in Z–R Relations", Journal of Applied Meteorology, 39, pp.1088~1102 (2000)
- Chumchean, S., "An Integrated Approach to Error Correction for Real-time Radar-rainfall Estimation", Journal of Atmospheric and Oceanic Technology, 23, pp.67~79 (2006)
- Ciach, G. J., "On the Estimation of Radar Rainfall Error Variance", Advanced Water Resources, 22, pp.585~595 (1999)
- Germann, U., "Radar Precipitation Measurement in a Mountainous Region", Quarterly Journal of the Royal Meteorologic Society, 132, pp.1669~1692 (2006)
- Huff, F. A, "Sampling Errors in Measurement of Mean Precipitation", Journal of Applied Meteorology, 9, pp.35~44 (1970)
- Jordan, P., "Sampling Errors in Radar Estimates of Rainfall", Journal of Geophysical Research : Atmospheres, 105, pp.2247~2257 (2000)
- Kim, D. S., "Reflectivity Z and Differencial Reflectivity ZDR Correction for Polarimetric Radar Rainfall Measurement", Proceeding of the Spring Meeting of Korean Meteorological Society (2006)
- Development of Collaboration Management System for Radar Data (I), "Korea Meteorological Administration", Weather Radar Center, ~ (2011)
- Development of Radar-based Multi-sensors Quantitative Precipitation Estimation, "Korea Meteorological Administration", Weather Radar Center, ~ (2012)
- Radar Rainfall Estimation Comparison and Verification Joint Experiment Report, "Korea Meteorological Administration", Weather Radar Center and Meteorological Advancement Council, Korea Meteorological Administration, ~ (2012)
- Krajewski, W. F., "Radar Hydrology : Rainfall Estimation", Advanced Water Resources, 25, pp.1387~1394 (2002)
- Lee, G. W., "Sources of Errors in Rainfall Measurements by Polarimetric Radar : Variability of Drop Size Distributions, Observational Noise, and Variation of Relationships between R and Polarimetric Parameters", Journal of Atmospheric and Oceanic Technology, 23, pp.1005~1028 (2006)
- McMillan, H., "Rainfall Uncertainty in Hydrological Modeling : An Evaluation of Multiplicative Error Models", Journal of Hydrology, 400, pp.83~94 (2011)
- Moulin, L., "Uncertainties on Mean Areal Precipitation : Assessment and Impact on Streamflow Simulations", Hydrology and Earth System Sciences, 13, pp.99~114 (2009)
- Oh, H. M., "Precipitation Rate Combined with the Use of Optimal Weighting of Radar and Rain Gauge Data", Atmosphere, 13(3), pp.316~317 (2003)
- Rosenfeld, D., "General Probability-matched Relations between Radar Reflectivity and Rain Rate", Journal of Applied Meteorology, 32, pp.50~72 (1993)
- Seo, D. J., "Real-time Estimation of Mean-field Bias in Radar Rainfall Data", Journal of Hydrology, 223, pp.131~147 (1999)
- Smith, J. A., "Estimation of Mean Field Bias of Radar Rainfall Estimates", Journal of Applied Meteorology, 30, pp.397~412 (1991)
- Villarini, G., "Empirically-based Modeling of Radar-rainfall Uncertainties", Ph.D., pp.2008
- Villarini, G., "Empirically-based Modeling of Spatial Sampling Uncertainties Associated with Rainfall Measurements by Rain Gauges", Advanced Water Resources, 31, pp.1015~1023 (2008)
- Villarini, G., "Sensitivity Studies of the Models of Radar-rainfall Uncertainties", Journal of Applied Meteorology and Climatology, 49, pp.288~309 (2010)
- Villarini, G., "Rainfall and Sampling Errors: A Rain Gauge Perspective", Journal of Geophysical Research, 113, pp.D11102~ (2008)
- Weather Radar Center, "Development of Integrated Quality Control Algorithm for Korean Radar Data", Korea Meteorological Administration, ~ (2013)
- Wilson, J. W., "Radar Measurement of Rainfall", Bulletin of American Meteorological Society, 60, pp.1048~1058 (1979)
- Woodley, W., "Comparison of Gage and Radar Methods of Convective Rain Measurement", Journal of Applied Meteorology, 14, pp.909~928 (1975)
- Yoo, C., "Use of the Kalman Filter for the Correction of Mean-field Bias of Radar Rainfall", The 5th Korea-Japan-China Joint Conferenceon Meteorology (2011)
- Zhang, J., "National Mosaic and Multi-sensor QPE(NMQ)System : Desscription, Results, and Future Plans", Bulletin of the American Meteorological Society, 92, pp.1321~1338 (2011)
- Zhang, Y., "Subpixelscale Rainfall Variability and the Effects on the Separation of Radar and Gauge Rainfall Errors", Journal of Hydrometeorology, 8, pp.1348~1363 (2007)