激光雷达反演参数k值的研究

Reserch on Logarithmic Ratio k of Aerosol Backscatter Extinction Using Lidar

采用532 nm激光雷达2006年在兰州市不同天气状况下的观测数据,结合能见度因子、CE318太阳光度计观测数据,对利用Klett法求解时,k在不同天气状况下的取值进行了初步研究,结果表明:只有当0.7≤k≤1.0时,气溶胶消光系数的大小与能见度估算出的值相接近。但在k=0.7时,计算出的气溶胶消光系数正、负参半;k=1.0时,消光系数廓线在晴天无云的天气状况下同实际情况不符。通过进一步分析研究激光雷达和光度计的同期观测资料发现:k=0.8时,较合理的数据所占比例为100%,k=0.9为84%,k=1.0仅为12%。对兰州市区而言,利用激光雷达分析气溶胶光学特性时,取k=0.8或k=0.9较为合理。

Using the data of 532 nm lidar, visibility and CE318 in 2006, the different values of k and aerosol extinction coefficient in different weathers are analysed when using method of Klett. The result showed： only if 0.7≤k≤1.0, the aerosol extinction coefficient calculated by lidar and visibility was close. But when k = 0.7, some values of aerosol extinction coefficient were negative, when k = 1.0, the vertical distributing of aerosol extinction coefficient was untrue. Analysed farther by means of CE318 in the corresponding period, had a results that k=0.8 or k=0.9 is logical when calculating the aerosol extinction coefficient by using lidar in Lanzhou.