测量大气边界层高度的激光雷达数据反演方法研究

大气边界层与人类关系最为密切,它的高度分布直接反映了近地面的大气状况.而今激光雷达已成为探测大气边界层时空演变特征的最有效手段,但如何从大量的测量数据中精确提取大气边界层高度则成为限制其应用的主要问题.介绍了四种常用的大气边界层高度提取方法,即梯度法、标准偏差法、曲线拟合法和小波协方差变换法,并结合自行研制的偏振拉曼-米散射激光雷达的实测数据,分别对四种方法的提取结果进行分析.结果表明:四种方法各有优缺点,梯度法、标准偏差法和小波协方差变换法比较相近,准确性高但不稳定；而曲线拟合法的稳定性好,但提取结果相对折中.总体而言,曲线拟合法更适用于大量数据的批处理运算.

Comparison of Retrieval Methods of Planetary Boundary Layer Height from Lidar Data

As the most closely related layer with human,the planetary boundary layer’s height directly reflects the state of the atmosphere near the ground.Now the lidar has become the most effective tool to observe the planetary boundary layer,but the retrieval of the planetary boundary layer height from a large number of measured data limited its application.Four kinds of commonly used methods,such as the gradient method,standard deviation method,fitting method and wavelet covariance transform method,are introduced and analyzed,with the continuously measured data of polarization-Raman-Mie scattering lidar.The results show that the four methods have their own advantages and disadvantages.The gradient method,the standard deviation method and the wavelet covariance transform method are similar and accurate in data process,but not stable.The fitting method has good stability,but its derivation is not so accurate relative to the three methods above.All in all,the fitting method is better to be used to process a large number of data.