双线偏振雷达差分传播相移的小波滤波初探  

Preliminary study on wavelet filtering of differential propagation phase shift for dual linear polarization radar

作　　者：杜牧云[1,2] 刘黎平[1] 胡志群[1] 余蓉[3] 

机构地区：[1]中国气象科学研究院灾害天气国家重点实验室,北京100081 [2]武汉中心气象台,武汉430074 [3]湖北省防雷中心,武汉430074

出　　处：《暴雨灾害》2012年第3期248-254,共7页Torrential Rain and Disasters

基　　金：国家自然科学基金项目(40975013);中国气象科学研究院基本科研业务项目(2011Z001)及"大气水凝物微物理参数及风场垂直结构多波长遥感探测和反演方法研究"和"青藏高原观测预试验与资料分析研究"

摘　　要：根据中国气象科学研究院灾害天气国家重点实验室的车载C波段双线偏振多普勒雷达外场观测资料,利用Daubechies小波对雷达观测的差分传播相移ΦDP进行滤波处理,并与滑动平均和中值滤波这两种常规处理方法的滤波效果进行对比分析。结果表明,Daubechies小波方法不仅同两种常规处理方法一样能有效剔除差分传播相移ΦDP存在的各种脉动与毛刺,使ΦDP数据具有更好的连续性和平滑度,还能有效地保留非气象回波信息,方便对其进行地物识别等后续处理;此外,其对弱信号的滤波效果也有显著提高,滤波后的ΦDP及其估算的差分传播相移率KDP与反射率因子ZH均有较好的对应关系。In this paper, the wavelet analysis method for filtering application of differential propagation phase shift for dual-linear polariza- tion radar has been discussed preliminarily. Based on the observation in field experiments by a C-band Polarimetric Doppler Radar on Wheel （CPDRW） which was built in the State Key Laboratory of Severe Weather （LaSW）, Chinese Academy of Meteorological Sciences （CAMS）, Daubechies wavelet is used to filter the differential propagation phase shift ФDP, and comparative analysis with the effect of moving average and median filtering, the two conventional processing methods in the filtering effect, arc performed. The results show that this method can eliminate the pulsation and burr existing in the differential propagation phase shift ФDPeffectively and has more obvious fihering effect than the other two conventional methods. Not only has ФDP data better continuity and smoothness, but also retains effectively the non-meteorologi- cal echo information to facilitate the subsequent processing such as ground clutter identification. In addition, it has also significantly improved the weak signal filtering effect. Both filtered ФDP and its estimations of specific differential propagation phase shift KDp correspond better with the reflectivitv Z. and differential reflectivitv ZDR.

关 键 词：双线偏振雷达 差分传播相移 小波滤波 

分 类 号：TN959.4[电子电信—信号与信息处理]