The Invariant Imbedding (IIM) T-matrix method has been recognized as one of the most promising method to derive exact solution of the light scattering properties of the nonspherical atmospheric particles after the significant improvement by Bi L. and Yang P. Compared with DDA (Discrete Dipole Approximation) and the time domain methods, it can calculate the scattering properties of the random-oriented particles analytically once the T-matrix of the particle is obtained. In order to better understand the modeling capability of this model and optimize the parameter settings for the particles with different geometrical and optical properties, the factors influencing the modeling accuracy are systematically analyzed, which includes the discretization schemes of the radial integral, the discrete point numbers of the radial, zenith and azimuthal integrals. The results show that, the calculation accuracy of Gaussian quadrature technique is higher than that of the trapezoidal rule in the radial discretization. For particles with large size parameter or refractive index, the density of the discrete points (both for the radial discretization and the mesh generation of the zenith and azimuth angles) should be increased correspondingly to ensure the calculation accuracy. Finer discrete grids are also required for particles with extreme shapes (e.g., particles with large aspect ratios). Based on the analysis above, the method to determine the parameters of scattering simulation is further proposed for particles with different geometrical and optical properties, by which the discretization of the computational domain can be optimized once the refractive index and geometry of the particle are known. The method is also validated for cylinders and hexagonal prisms, the results shows that the optimization scheme can be applicable to particles with different shapes.

在Bi L.和Yang P的显着改进之后，不变嵌入（IIM）T矩阵方法被认为是获得非球形大气颗粒的光散射特性的精确解的最有前途的方法之一。与DDA（离散偶极近似法和时域方法，一旦获得粒子的T矩阵，它就可以解析地计算随机取向粒子的散射特性。为了更好地了解该模型的建模能力并优化具有不同几何和光学性质的粒子的参数设置，系统地分析了影响建模精度的因素，包括径向积分离散化方案，离散点数径向的 天顶和方位角积分。结果表明，在径向离散化中，高斯正交技术的计算精度高于梯形法则。对于具有较大尺寸参数或折射率的粒子，应相应增加离散点的密度（用于径向离散化以及天顶角和方位角的网格生成），以确保计算精度。对于具有极端形状的粒子（例如，具有大长宽比的粒子），还需要更细的离散网格。在以上分析的基础上，进一步提出了确定具有不同几何和光学性质的粒子的散射模拟参数的方法，一旦知道粒子的折射率和几何形状，就可以优化计算域的离散化。该方法还针对圆柱和六棱柱进行了验证，结果表明该优化方案适用于不同形状的粒子。