摘要：采用T矩阵方法计算亚微米级扁椭球随机取向分布颗粒群的散射特性,研究消光截面、散射截面、吸光截面、单散射反照率、非对称因子以及散射矩阵元素与颗粒的大小、折射率、长短轴比之间的关系。结果表明,随颗粒粒径增大,消光截面、散射截面、吸光截面、非对称因子都单调增加,散射相函数F11的角分布曲线特征可以区分颗粒的大小;颗粒越偏离球形,颗粒对入射光的衰减效率越低,后向散射光强越强,在轴比不大时,前向50°内的F22/F11值可以区分颗粒的形状;折射率变化主要是对后向散射光的分布产生影响,实部、虚部的变化可分别通过F34/F11的角分布曲线、F12/F11的第一个峰值来体现。

关键词：扁椭球；散射特性；折射率；T 矩阵

Abstract：The light scattering characteristics of random oriented sub-micron oblate spheroidal particle clusters were calculated by T-matrix method.The relationships between extinction cross section,scattering cross section,absorption cross-section,single scattering albedo,asymmetry factor,the scattering matrix elements and size,refractive index,axial ratio of particles were studied systematically,and the characterization methods for characteristic parameters of particles was obtained.The results indicate that with the increase of particle size,the extinction cross section,scattering cross section,absorption cross-section,single scattering albedo increase monotonically.The size of particles is differentiated by the scattering angle distribution curves of phase function F11.The more deviation in the shape from the spherical particles is,the lower the attenuation efficiency is.The shape of the particles is differentiated by the F22/F11 value within 50°when the axial ratio is smaller than 5.The change of refractive index impacts largely on the angle distribution of backward scattering.The changes of the real and imaginary part of refractive index are reflected by the angle distribution curve of F34/F11 and the first peak value of the angle distribution curve of F12/F11 respectively.

Keywords：oblate spheroid；scattering characteristics；refractive index；T-matrix method