云的多次散射对激光雷达测量结果影响的研究

Study of clouds multiple-scattering influence on lidar measurement

为了更加准确地获得大气消光系数和后向散射系数,利用半解析Monte Carlo方法对云的大气多次散射激光雷达回波信号进行了模拟计算。分析了激光雷达接收视场角及光学厚度对多次散射回波信号的影响及水云和卷云多次散射因子与光学厚度的关系。激光雷达测量数据的对比结果表明,多次散射对卷云和水云消光系数影响较明显,而对后向散射系数的影响可以忽略。

Lidar multiple scattering return from clouds was simulated by means of semianalytie Monte Carlo method in order to obtain atmosphere extinction and backscattering coefficeint exactly. The influence of the receiver field of view and medium optical depth on multiple scattering was discussed. The relation between cirrus/water clouds of multiple scattering factor and optical depth was studied. The results show that the presence of the multiple scattering can lead to an underestimation of the extinction coefficient and has little influence on backscattering coefficient.