X波段双线偏振雷达不同衰减订正法对比分析
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摘要
X波段双线偏振雷达的衰减是影响其回波强度(ZH)和差分反射率因子(ZDR)应用的主要问题,影响了雷达的探测精度以及降水估测的精度。考虑到传播相移率(K_(DP))在低信噪比情况下数据质量问题,本文对比了4种订正方法(Z_H-K_(DP)法,整段ZPHI法,20库ZPHI法,80库ZPHI法)的订正效果,将广州S波段双线偏振雷达数据作为标准来评判佛山X波段双线偏振雷达衰减订正效果,由于两部雷达的位置差异,为了得到精确的点对点(方位角、仰角、距离库)的数据对,对广州S波段双线偏振雷达数据进行坐标转换以及插值处理,通过与广州S波段雷达数据进行对比分析相对偏差以及相关系数等,得出ZPHI订正法的效果要优于Z_H-K_(DP)综合订正法。
The attenuation of X-band dual polarimetric radar is the main problem in application of echo strength and differential reflectivity factor(Z_H and Z_(DR)).It has a strong impact on the radar detecting precision and rainfall estimation.In consideration of the quality problem of K_(DP) in the low SNR situation,we used four kinds of attenuation correction methods:Z_H-K_(DP) and three kinds of segmented ZPHI methods.To have a better judgment of the Foshan X-band radar correction results of different methods,we used the data of the Guangzhou S-band radar as standards.But due to the different position information of two radars,the S-band radar data must be processed by coordinate conversion and interpolation processing.Then we got data pairs with same elevation,azimuth and range.After qualitative and quantitative analysis,we find that ZPHI is superior to Z_H-K_(DP) in relative deviation and correlation coefficient.
The attenuation of X-band dual polarimetric radar is the main problem in application of echo strength and differential reflectivity factor(Z_H and Z_(DR)).It has a strong impact on the radar detecting precision and rainfall estimation.In consideration of the quality problem of K_(DP) in the low SNR situation,we used four kinds of attenuation correction methods:Z_H-K_(DP) and three kinds of segmented ZPHI methods.To have a better judgment of the Foshan X-band radar correction results of different methods,we used the data of the Guangzhou S-band radar as standards.But due to the different position information of two radars,the S-band radar data must be processed by coordinate conversion and interpolation processing.Then we got data pairs with same elevation,azimuth and range.After qualitative and quantitative analysis,we find that ZPHI is superior to Z_H-K_(DP) in relative deviation and correlation coefficient.
引文
[1]Park S G,Bringi V.Correction of radar reflectivity and differential reflectivity for rain attenuation at X band.Part I:Theoretical and empirical basis[J].Journal of Atmospheric and Oceanic Technology,2005,22(11):1622.
[2]Park S G,Maki M,Iwanami K,et al.Correction of radar reflectivity and differential reflectivity for rain attenuation at X band.PartⅡ:Evaluation and application[J].Journal of Atmospheric and Oceanic Technology,2005,22(11):1633-1655.
[3]Hitschfeld W,Bordan J.Errors inherent in the radar measurement of rainfall at attenuating wavelengths[J].Journal of Meteorology,1954,11(1):55-67.
[4]Bringi V N,Chandrasekar V,Balakrishnan N,et al.An examination of propagation effects in rainfall on radar measurements at microwave frequencies[J].Journal of Atmospheric&Oceanic Technology,2009,7(7):829-840.
[5]Ryzhkov A,Zrnic D S.Precipitation and attenuation measurement at a 10-cm wavelength[J].Journal of Applied Meteorology,1995,34(10):2121-2134.
[6]Testud J,Bouar E L,Obligis E,et al.The rain profiling algorithm applied to polarimetric weather radar[J].Journal of Atmospheric&Oceanic Technology,2000,17(3):332-356.
[7]Bouar E L,Testud J.Validation of the rain profiling algorithm“ZPHI”from the c-band polarimetric weather radar in darwin[J].Journal of Atmospheric and Oceanictechnology,2001,18(18):1819-1837.
[8]Testude.The concept of“normalized”distribution to describe raindrop spectra:a tool for cloud physics and cloud remote sensing[J].Journal of Applied Meteorology,2001,40(40):1118-1140.
[9]Bringi V N,Chandrasekar V.Polarimetric doppler weather radar[M].Lodon:Cambridge University Press,2001:159-160.
[10]胡志群,刘黎平,楚荣忠.X波段双线偏振雷达不同衰减订方法对比及其对降水估测影响研[J].气象学报,2008,66(2)251-261.
[11]毕永恒,刘锦丽,段树,等.X波段双线偏振气象雷达反射率的衰减订正[J].大气科学,2012,36(3),495-506.
[12]赵世颖,李柏,陈晓辉,等.基于交叉-平行法的双线偏振雷达差分反射率硬件定标[J].气象科技,2015,43(5):775-782.
[13]李喆,李柏,赵坤,等.国产双偏振天气雷达差分反射率测量性能分析[J].气象科技,2016,44(6):854-861.
[14]郑佳峰,张杰,朱克云,等.双偏振雷达测雨误差及水凝物识别分析[J].气象科技,2014,42(3):364-372.
[15]Chandrasekar V,Lim S.Simulation of path-integrated attenuation for X-band rainfall observation for S-band radar data[J].J Atmos Oceanic Technol,2006,23(9):1195-1205.
[16]吴翀,刘黎平,张志强.S波段相控阵天气雷达与新一代多普勒天气雷达定量对比方法及其初步应用[J]气象学报,2014,42(2),391-395.
[2]Park S G,Maki M,Iwanami K,et al.Correction of radar reflectivity and differential reflectivity for rain attenuation at X band.PartⅡ:Evaluation and application[J].Journal of Atmospheric and Oceanic Technology,2005,22(11):1633-1655.
[3]Hitschfeld W,Bordan J.Errors inherent in the radar measurement of rainfall at attenuating wavelengths[J].Journal of Meteorology,1954,11(1):55-67.
[4]Bringi V N,Chandrasekar V,Balakrishnan N,et al.An examination of propagation effects in rainfall on radar measurements at microwave frequencies[J].Journal of Atmospheric&Oceanic Technology,2009,7(7):829-840.
[5]Ryzhkov A,Zrnic D S.Precipitation and attenuation measurement at a 10-cm wavelength[J].Journal of Applied Meteorology,1995,34(10):2121-2134.
[6]Testud J,Bouar E L,Obligis E,et al.The rain profiling algorithm applied to polarimetric weather radar[J].Journal of Atmospheric&Oceanic Technology,2000,17(3):332-356.
[7]Bouar E L,Testud J.Validation of the rain profiling algorithm“ZPHI”from the c-band polarimetric weather radar in darwin[J].Journal of Atmospheric and Oceanictechnology,2001,18(18):1819-1837.
[8]Testude.The concept of“normalized”distribution to describe raindrop spectra:a tool for cloud physics and cloud remote sensing[J].Journal of Applied Meteorology,2001,40(40):1118-1140.
[9]Bringi V N,Chandrasekar V.Polarimetric doppler weather radar[M].Lodon:Cambridge University Press,2001:159-160.
[10]胡志群,刘黎平,楚荣忠.X波段双线偏振雷达不同衰减订方法对比及其对降水估测影响研[J].气象学报,2008,66(2)251-261.
[11]毕永恒,刘锦丽,段树,等.X波段双线偏振气象雷达反射率的衰减订正[J].大气科学,2012,36(3),495-506.
[12]赵世颖,李柏,陈晓辉,等.基于交叉-平行法的双线偏振雷达差分反射率硬件定标[J].气象科技,2015,43(5):775-782.
[13]李喆,李柏,赵坤,等.国产双偏振天气雷达差分反射率测量性能分析[J].气象科技,2016,44(6):854-861.
[14]郑佳峰,张杰,朱克云,等.双偏振雷达测雨误差及水凝物识别分析[J].气象科技,2014,42(3):364-372.
[15]Chandrasekar V,Lim S.Simulation of path-integrated attenuation for X-band rainfall observation for S-band radar data[J].J Atmos Oceanic Technol,2006,23(9):1195-1205.
[16]吴翀,刘黎平,张志强.S波段相控阵天气雷达与新一代多普勒天气雷达定量对比方法及其初步应用[J]气象学报,2014,42(2),391-395.