基于双向重构后向散射信号的微脉冲激光雷达云层检测算法  

Cloud Detection Algorithm of Micro-Pulse Lidar Based on Bidirectional Reconstruction of Backscatter Signal

作　　者：孟园园 常建华[1,2] 陈思成 周妹 戴腾飞 王博业 姜炎宋 Meng Yuanyuan;Chang Jianhua;Chen Sicheng;Zhou Mei;Dai Tengfei;Wang Boye;Jiang Yansong(School of Electronics&Information Engineering,Nanjing University of Information Science&Technology,Nanjing 210044,Jiangsu,China;Collaborative Innovation Center of Atmospheric Environment and Equipment Technology,Nanjing University of Information Science&Technology,Nanjing 210044,Jiangsu,China)

机构地区：[1]南京信息工程大学电子与信息工程学院,江苏南京210044 [2]南京信息工程大学江苏省大气环境与装备技术协同创新中心,江苏南京210044

出　　处：《光学学报》2022年第24期181-194,共14页Acta Optica Sinica

基　　金：国家自然科学基金(61875089,62175114);江苏省高等学校大学生创新创业训练计划(202010300040)。

摘　　要：在理想的洁净大气条件下,微脉冲激光雷达后向散射信号强度具有随高度单调变化的特征。提出了一种基于插值重构方法的云层垂直结构反演算法,以探测距离最低处和最高处为起点和参考点,筛选预处理信号中相应的插值点进行Akima插值。将得到的前向和后向重构信号进一步作平均处理以模拟无云信号。所提算法先结合自适应阈值与经验阈值区分云和气溶胶,确定候选云层区间,再在此基础上,对比模拟的无云信号与预处理信号强度,提取候选云层的云底和云顶高度。利用微脉冲激光雷达数据进行的验证表明,相比于直接反演的传统算法,所提算法的云底和云顶高度的相关系数分别提高至0.9836和0.9334,均方根误差分别减小至43.8 m和280.2 m,有效提高了云层检测的精度。Under ideal clean atmosphere conditions, the backscatter signal intensity of micro-pulse lidar has a monotonic variation with height. An inversion algorithm of cloud vertical structure based on the interpolation and reconstruction method is proposed to screen the corresponding interpolation points in the pre-processed signal for Akima interpolation,with the places with the lowest and highest detection distances as the starting point and reference point, respectively. The obtained forward and backward reconstructed signals are further averaged to simulate the cloud-free signal. Clouds and aerosols are first distinguished by the proposed algorithm combining the adaptative threshold and empirical threshold to determine the candidate cloud interval. On this basis, the intensity of the simulated cloud-free signal is compared with that of the pre-processed signal, and the cloud base and cloud top heights of the candidate clouds are extracted. The validation using micro-pulse lidar data shows that compared with the results of the traditional direct inversion algorithm, the correlation coefficients of the cloud base and cloud top are improved to 0. 9836 and 0. 9334, and the root mean square errors are reduced to 43. 8 m and 280. 2 m, which indicates that the proposed method effectively improves the accuracy of cloud detection.

关 键 词：遥感 微脉冲激光雷达 云层检测 插值 重构 大气光学 

分 类 号：TN958.98[电子电信—信号与信息处理]