基于相函数分段加权采样的近红外激光传输特性  

Laser Transfer Properties of Aerosols at Near-Infrared Waveband Based on Sectional-Weighted Sampling of Scattering Phase Functions

作　　者：胡帅[1] 高太长[1] 李浩[1] 刘磊[1] 刘西川[1] 李云[1] 韩文宇[1] 

机构地区：[1]解放军理工大学气象海洋学院,江苏南京211101

出　　处：《中国激光》2015年第8期42-51,共10页Chinese Journal of Lasers

基　　金：国家自然基金项目(41475020;41475025)

摘　　要：为提高Monte Carlo激光传输模型中散射过程的处理精度,依据散射相函数的变化特征,提出了相函数分段加权采样方案,验证了其准确性与可行性。采用Monte Carlo方法模拟了在非球形沙尘气溶胶中,1.06μm红外激光透射率、反射率随传播距离的变化规律,并将Henyey-Greenstein(H-G)相函数采样与相函数均匀采样方案的Monte Carlo模拟结果进行了比较。仿真结果表明;相函数分段加权采样方案可显著降低相函数抽样误差,提高空间散射角抽样精度;与H-G相函数抽样的模拟结果相比,采用H-G相函数模拟的透射率偏低,反射率偏高,且随距离增大,两者结果偏差随之增大。与相函数均匀采样的模拟结果相比,两者计算的透射率偏差值随距离增大而增大,反射率反之。To improve the simulation accuracy of scattering process in Monte Carlo radiative transfer model, a phase function sectional-weighted sampling method is put forward based on the characteristics of scattering phase functions, and its accuracy and feasibility are validated subsequently. Transmissivity and reflectivity of infrared laser（1.06 mm） in non-spherical sand aerosol are calculated using Monte Carlo method. Its results are compared with those of Henyey-Greenstein（H-G） phase function sampling method and phase function uniformly-sampling method. Simulation results show that, phase function sectional- weighted sampling method can improve the calculation accuracy of scattering angles obviously and reduce the sampling error of phase function. Compared with H-G phase function sampling method, transmissivity calculated by H-G formula is underestimated, while reflectivity calculated by H-G formula is overestimated, and the deviation of two methods increases with the increasing of propagation distance. Compared with phase function uniformly sampling method, the relative error of transmissivity increases with the propagation distance increasing, while the relative error of reflectivity changes oppositely.

关 键 词：激光光学 相函数 分段加权采样 红外激光传输 MONTE Carlo 

分 类 号：P426.31[天文地球—大气科学及气象学]