与散射相函数相关的光源附近微区漫反射

Diffuse Reflection Associated with Scattering Phase Function from a Micro-region Close to the Source

采用Monte Carlo法研究散射相函数对光源附近微区内的漫反射光的影响,分析一个半经验的漫反射解析模型与相函数相关的光学参量之间的关系.研究表明,来自光源附近微区的散射光对散射相函数的变化非常敏感,敏感程度随收集孔径φ的增大而逐渐减弱.当φ>1.8mm时,散射相函数对漫反射率的影响不明显,反射率的相对变化小于1%;当φ<1.8mm时,散射相函数对漫反射率的影响高达15.2%.用各向异性因子g和二阶光学参量γ表征单粒子散射特性时,散射特性的差异反应在三阶参量δ上.漫反射率随δ的增加而减小,并且δ对漫反射率的影响达到9%.

Influence of the scattering phase function on the diffuse reflection of a micro-region close to the source was investigated by Monte Carlo simulations,and relationship between a semi-empirical model of diffuse reflection and the optical parameters related to the phase function was analyzed.Research shows that the scattered light of the micro-region close to the source is very sensitive to the scattering phase function,and the sensitivity will gradually weaken with increasing of collection apertureφ.Whenφ〉1.8mm,influence of the scattering phase function on the diffuse reflection is not obvious and relative change in reflectivity is less than 1%;whenφ〈1.8mm,influence of the scattering phase function on the diffuse reflection can reach up to 15.2%.When the anisotropic factor gand the second-order optical parameterγare used to characterize a single-particle scattering properties,the differences of scattering properties are reflected in the third-order parameterδ.The diffuse reflectance decreases with the increasing ofδand the influence ofδon the diffuse reflectance can reach 9%.