
第 42 卷 第 8 期
2015 年 8 月
Vol. 42, No. 8
August, 2015
中 国 激 光
CHINESE JOURNAL OF LASERS
0802008-
基于相函数分段加权采样的近红外激光传输特性
胡 帅 高太长 李 浩 刘 磊 刘西川 李 云 韩文宇
解放军理工大学气象海洋学院, 江苏 南京 211101
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,1.06 μm 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。
关键词 激光光学; 相函数; 分段加权采样; 红外激光传输; Monte Carlo
中图分类号 P426.3+1 文献标识码 A
doi: 10.3788/CJL201542.0802008
Laser Transfer Properties of Aerosols at Near-Infrared Waveband
Based on Sectional-Weighted Sampling of Scattering Phase Functions
Hu Shuai Gao Taichang Li Hao Liu Lei Liu Xichuan Li Yun Han Wenyu
College of Meteorology and Oceanography, PLA University of Science and Technology, Nanjing, Jiangsu 211101, China
Abstract 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.
Key words laser optics; phase function; sectional-weighted sampling; infrared laser transfer; Monte Carlo
OCIS codes 140.3500; 140.3510; 140.3550; 140.3570
收稿日期: 2015-01-15; 收到修改稿日期: 2015-02-10
基金项目: 国家自然基金项目(41475020,41475025)
作者简介: 胡 帅(1990—),男,博士研究生,主要从事大气探测与遥感等方面的研究。E-mail: hushuai2012@hotmail.com
导师简介: 高太长(1958—),男,教授,博士生导师,主要从事军事大气探测等方面的研究。
.E-mail: 2009gaotc@gmail.com(通信联系人)
1 引 言
大气气溶胶指悬浮于大气中直径在 0.01~100 μm 的液体或固体微粒体系,是地气系统的重要组成部分
[1-3]
。
气溶胶尺度在微米级,对近红外波段有较强的散射与吸收作用
[4-5]
,可对红外激光传输
[6]
、红外遥感
[7]
及目标探
测
[8]
等产生重要影响,特别在气溶胶光学厚度较大时,多次散射效应增强,其影响更为显著
[9-10]
。散射相函数
是描述气溶胶散射特性的重要参数,表征的是散射能量空间分布特征
[11]
。在辐射传输模型中,根据相函数资
1