旋转扁椭球水滴散射特性的快速算式研究  

Study of Quick Formulas for Calculating Liquid Oblate Spheroid Scattering Properties

作　　者：郭丽君[1,2] 王振会[1,2] 董慧杰[2] 吴迪[2] 张培昌[2] 

机构地区：[1]南京信息工程大学气象灾害省部共建教育部重点实验室,江苏南京210044 [2]南京信息工程大学大气物理学院,江苏南京210044

出　　处：《高原气象》2012年第4期1081-1090,共10页Plateau Meteorology

基　　金：国家自然科学基金项目(40875016);国家高技术研究发展计划(863计划)(2007AA061901)共同资助

摘　　要：利用DDA(Discrete Dipole Approximation)算法产生的旋转扁椭球水滴散射特征数据进行了多项式拟合,以3.2mm波长为例,给出了两种偏振状态下后向散射和衰减效率的快速算式。对比分析了快速算式结果和DDA数据的独立样本,结果表明,快算结果的绝对相对误差在5%以内,而耗时仅用DDA算法产生这些数据所用时间的10-6量级。所得结果可直接用于云降水区含扁椭球形水滴情况下的雷达回波模拟、雷达资料定量处理和毫米波雷达的衰减订正等,此方法还可用于其他波长、形状的水滴和冰晶。Using the DDA data of the scattering properties of liquid oblate spheroid, the Quick For- mulas for calculating backscattering and extinction efficiency factors are obtained by multinomial fitting under the states of horizontal and vertical polarization at a wavelength of 3.2 mm. The comparing with the Quick Formulas and DDA results based on the same quantity of independent data shows that the abso- lute relative error of the Quick Formulas is within 5 %, which the time consumption is only one million of DDA. The results of Quick Formulas can be applied in many ways, namely radar reflectivity simulating, radar data processing quantitatively and the correction of attenuation in the cloud and precipitation area containing liquid oblate spheroid. The thought of the paper could be used in other wavelengths, shapes and phase states.

关 键 词：双线偏振雷达 旋转扁椭球水滴 DDA 快速算式 

分 类 号：P406[天文地球—大气科学及气象学]