介绍一种激光雷达常数标定和气溶胶光学厚度(AOD)测量的新方法。利用太阳辐射计，获得大气气溶胶的光学厚度，激光雷达可以获得35～40km高度的回波信号，在这一高度区间可忽略气溶胶的存在，大气模式可以提供大气分子散射系数，根据激光雷达方程计算出激光雷达常数。反之，标定激光雷达常数后，根据激光雷达方程，以激光雷达35～40km的大气分子后向散射回波信号来确定气溶胶的光学厚度。激光雷达测量结果与太阳辐射计的测量结果一致性较好，说明该方法是可行的。这种新方法既可以用于白天的气溶胶光学厚度测量，也可以用于夜间测量。

A new method is presented to calibrate lidar constant. Atmospheric aerosol optical depths(AOD)were measured by solar radiometer and lidars were used to acquire backscattering signals from aerosol free-loading regions 35 to 40 km altitude. Atmospheric model provides molecular scattering coefficient. Lidar constant can be calculated according to lidar equation. After lidar constant was calibrated using solar radiometer,aerosol optical depth can be determined with lidar return signals from 35 to 40 km altitude according to lidar equation. A good agreement between lidar measurements and solar radiometer measurements shows that our method for AOD measured by lidar is feasible. This method can be used to measure AOD on daytime and nighttime.