卷云散射的蒙特卡罗法模拟

在对空中目标观测时，高空卷云的散射对目标检测与识别产生了重要影响。鉴于此，该文概述了卷云中规则几何形状冰晶粒子的单次散射计算方法，以及卷云中冰晶粒子的分布情况。对卷云中冰晶粒子的微观物理特性做了进一步探讨，并假设卷云尺度谱遵从Gamma分布，模拟了光波波长0.4～4mm，粒子有效半径为10～120mm的卷云单次散射角与相函数的关系，利用Monte Carlo方法对光子与云滴的碰撞作用后产生多次散射概率进行了建模与仿真。仿真结果表明，卷云的光学厚度随多次散射阶数的增加而增大。

Numerical Simulation of Cirrus Scattering with the Monte Carlo Method

While a spatial object is observed by a ground detection system, some important influence of cirrus scattering on the target detection and identification might occur. In this paper, a review of single scattering and distribution properties of regular geometric cirrus particle is given. Micro physical properties are analyzed ulteriorly. Based on an assumption that size distribution of cirrus particles is a Gamma function, the phase function with the scattering angle is simulated within wavelength 0.4 mm to 4 mm and effective radius 10 mm to 120 mm. An approximate model of multiple scattering probability concerning ice crystal particles and photons is proposed. Numerical results show that optical depth of cirrus increases with the order of multiple scattering.