扫描激光雷达可以获取大气剖面，对于了解边界层与云的结构、污染物分布与输送有重要的作用。斜程扫描下，天顶角较大时传统Fernald和Klett消光系数反演方法不再适用，可采用经典两角度方法对激光雷达常数进行校正，进而获取大气消光系数。但经典两角度法求解雷达常数时存在多解问题，如何设定约束条件求取最优解是较难解决的问题。从经典两角度方法出发，在两条斜程上筛选出的大气缓变区域，假定水平均匀，通过线性回归的方法估算雷达常数，并采用一系列约束条件以求取雷达常数最优解，最终得到斜程扫描下消光系数分布，较好地解决了两角度测量中多解问题求解的困难。通过实验验证，即使在天顶角较大或者信号质量不是很好的情况下，消光系数反演依然能够获得较好的效果。结果表明，该方法能够很好地反映出大气的空间结构。

Scanning lidar can produce a profile image about atmosphere and play an important role in studying boundary layer, structure of cloud, distribution and transport of air pollution. However, traditional Fernald and Klett methods cannot be applied to the situation of large zenith angles. Usually, by using two-angle method, the lidar constant is corrected, and then atmospheric extinction coefficient is obtained. But this is a multiple-solution problem. It is difficult to optimize the solutions just by setting some relevant conditions. The atmospheric region between adjacent slant paths is basically horizontally uniform. The lidar constant is estimated by using linear regression in that region. Then the best lidar constant is optimized with relevant constraints. The atmospheric extinction coefficient is inverted. By theoretical simulated and measured data analysis, the inversion result is still very good even when the zenith angle is large and lidar signal quality is not very good. Results show that this method can display atmospheric structure very well.