双线偏振多普勒雷达资料质量的定量评估

以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2011年在云南洱源的外场观测资料为例,通过雷达质量指数算法将影响雷达资料质量的主要因子——波束展宽、波束遮挡、地物杂波污染、电磁波衰减等,以距离库为单元按0-1的取值范围量化处理,以此对雷达资料质量进行定量评估。其中,质量指数越接近0就表示雷达资料受各因子影响越大,质量越差;质量指数越接近于1,表示雷达资料受各因子影响越小,质量越好。根据该定量评估结果可以直观地了解资料质量受各因子的影响程度及其整体情况,并方便根据不同的应用需要来筛选数据。

A quantitative evaluation of the data quality of dual linear polarimetric Doppler radar

In this paper, based on the field observation experiment in Eryuan,Yunnan Province in 2011 by the C-band Dual-lincar Polarimetric Doppler Radar on Wheel (CPDRW) which was built in the State Kcy Laboratory of Severe Weather(LaSW), Chinese Academy of Meteorological Sciences (CAMS),the influence of beam broadening, beam shielding, ground clutter contamination and attenuation of electromagnetic energy by hydrometcors on the quality of the radar measurement is evaluated by the radar quality-index algorithms that arc able to identify and estimate the amount of contamination.The output result that ranges between zero and one is encoded on a pixel-by-pixel basis into quality-index fields.The more the quality intex is close to zero,the more the radar data arc influenced by each affecting factor, and vice versa.According to the quantitative evaluation results, we can directly understand the affection degree of radar data by each affecting factor and the overall quality of the data, and choose the amount of data and the level of quality used for the different requirements easily.