本文为了改装双线偏振雷达的需要,用扩展边界条件法计算了椭球形雨滴的后向散射截面、衰减截面及吸收截面,得出了任意谱参数情况下,可能产生的散射强度及差反射率因子Z_DR值的大小。给出了降雨强度、衰减系数和双线偏振雷达观测量间的关系。为双线偏振雷达定量测量降雨工作及讨论雨区对雷达波衰减打下了基础。

Aimed at developing a dual linear polarization radar, we have calculated backscattering, extinction and absorbing cross sections of oblate spheroidal raindrops by using the extended boundary condition method. The scattering intensities and the differential reflectivities (Z_DR) for different hydrometeors with any spectral parameters have been obtained. We have also given the relationships between rain rates, extinction coefficients and the parameters measured by the dual linear polarization radar. This work has laid the foundation of quantitative measurement of rain rate and the discussion of extinction properties of radar wave in rain clouds.