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湍流廓线激光雷达是近十年出现的测量大气湍流强度廓线的新技术,目前数据处理已成为该技术的关键环节。对湍流廓线激光雷达的数据处理方法进行了详细地描述,重点研究了双光斑图像背景阈值计算方法与大气湍流强度廓线反演算法。比较了迭代法、最大类间方差法和统计法三种背景阈值计算方法分别在强信号与弱信号下的计算结果,得出统计法是比较适合双光斑图像的背景阈值计算方法。在背景阈值计算的基础上对图像进行分割并计算得到双光斑的质心距,统计多帧图像的质心距起伏得到达角起伏方差。然后利用HV-21模型模拟了从到达角起伏方差反演大气湍流强度廓线的算法,所得结果与原始值大小相近、整体变化趋势一致,但是不能反映原始值的细节变化趋势。
Turbulence profile laser radar is a new technique for measuring the intensity profile of atmospheric turbulence in recent ten years. Currently, data processing has become a key part of this technique. The data processing method of turbulent profile lidar is described in detail. The calculation method of background threshold and the algorithm of atmospheric turbulence profile inversion are mainly studied. Comparing the calculation results of the three kinds of background threshold calculation methods under the strong signal and the weak signal respectively by the iterative method, the maximum-class-variance method and the statistical method, it is concluded that the statistical method is a comparatively suitable background threshold calculation method for the dual-spot image. Based on the background threshold calculation, the image is segmented and the centroid distance of the two spots is calculated. The centroid fluctuation of the multi-frame image is obtained to obtain the angular fluctuation variance. Then, the HV-21 model is used to simulate the inversion of the atmospheric turbulence intensity profile from the undulating variance of the arrival angle. The obtained results are similar to the original values and the overall trends are the same, but they can not reflect the details of the original values.