差分像移湍流廓线激光雷达测量误差分析

Error Analysis of Differential Image Motion Lidar

差分像移激光雷达可以测量随距离分布的大气湍流廓线。在结合测量原理和定性分析的基础上,经过严格的数学推导得到了差分像移激光雷达测量湍流的误差公式,提供了定量分析和改进系统性能的基础:在系统参数确定后,通过合理分配探测点间距以及每个探测点的探测时间可以达到最好的测量效果。根据模拟分析的结果,测量误差主要来源于光斑质心计算误差和有限样本引起的统计误差。近距离测量时,由于接收到的光子信号很强,光斑质心计算误差的影响很小,此时样本统计误差起主导作用;随着距离的增加,光斑质心计算误差的影响越来越大。

Differential image motion lidar is used to measure profiles of atmospheric turbulence. A formula is deduced to quantify the error of differential image motion variance, which provides the basis of qualitative analysis and improvement of system performance. With reasonable arrangement of distance resolution and time resolution, the best measurement results can be obtained. According to analysis, two mainly error sources are the errors from centroid position of image and statistical uncertainty of finite sample. The simulation results show that statistical error is the dominant factor at lower altitude, while centroid calculation error plays an increasingly important role with the increasing of distance.