差分吸收激光雷达几何因子实验确定方法

差分吸收激光雷达发射光束与接收视场的重叠区域用几何因子函数来描述，几何因子是差分吸收激光雷达的重要参数。提出了一种实验方法，实验使用米散射激光雷达和差分吸收激光雷达同时测量信号，通过对比分析两台激光雷达采集信号计算得到的气溶胶散射比廓线，获得差分吸收激光雷达的几何因子。该方法的优点在于不需要预先得到精确度高的激光雷达参数，比如望远镜直径，光束发散角，望远镜接收视场角等。该方法的应用有利于减少近地面差分吸收激光雷达测量臭氧廓线的误差，提高差分吸收激光雷达的探测性能，有助于研究近地面层的臭氧时空分布特征。

Experimental determination of lidar geometric factor in differential absorption lidar

The lidar geometric factor describes the overlap between the laser beam and the receiver of field of view in differential absorption lidar. It is an important system parameter in differential absorption lidar. An experimental determination method of the lidar geometric factor is presented based on the comparison of aerosol scattering ratio profile derived from the signals measured by differential absorption lidar and Mie lidar simultaneously. The approach provides a means to determine the lidar geometric factor without an explicit knowledge of all lidar system parameter, such as the telescope diameter, laser beam divergence, telescope of field of view et al. The application of the proposed method can reduce the ozone measurement error of differential absorption liar and improve the potential of differential absorption lidar to investigate the spatial and temporal distribution characteristics of ozone.