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林业资源管理 ›› 2020›› Issue (3): 58-62.doi: 10.13466/j.cnki.lyzygl.2020.03.011

• 科学研究 • 上一篇    下一篇

无人机密集匹配点云与机载激光雷达点云的差异分析

林鑫1,2(), 庞勇2, 李春干1()   

  1. 1.广西大学 林学院,南宁 530004
    2.中国林业科学研究院资源信息研究所,北京 100091
  • 收稿日期:2020-04-27 修回日期:2020-06-02 出版日期:2020-06-28 发布日期:2020-07-30
  • 通讯作者: 李春干
  • 作者简介:林鑫(1995-),男,广西南宁人,在读硕士,主要研究方向:生态遥感。Email: xxfxhp@126.com
  • 基金资助:
    国家重点研发计划“多尺度落叶松人工林生长预测”(2017YFD0600404);科技部中国-捷克交流项目“基于无人机遥感的中幼林参数估测”(2019-43-16)

Analysis of the Deference Between the UAV Dense Matching Point Cloud and Airborne LiDAR Point Cloud

LIN Xin1,2(), PANG Yong2, LI Chungan1()   

  1. 1. Collegeof Forestry,Guangxi University,Nanning,530005,China
    2. Institute of Forest Resource Information Techniques,Chinese Academy of Forestry,Beijing,100091,China
  • Received:2020-04-27 Revised:2020-06-02 Online:2020-06-28 Published:2020-07-30
  • Contact: Chungan LI

摘要:

为分析无人机密集匹配点云和机载激光雷达点云的异同性,对密集林分(郁闭度0.85)、稀疏林分(郁闭度0.55)和未成林地的2种点云的空间分布进行目视对比分析,并通过2种点云生产的DEM(UAV_DEM和LiDAR_DEM)分别对密集匹配点云进行归一化处理,得到2套归一化密集匹配点云数据,将其与激光雷达点云进行统计特征参数配对样本t检验分析。结果表明:1)在密集林分中,密集匹配点云无法获取冠层内部和地面信息,采用LiDAR_DEM进行归一化后,密集匹配点云的中下部分位数高度及全部分位数密度与激光雷达点云相应统计特征参数均存在显著性差异(α=0.05),但中上层分位数高度的差异不显著;2)在稀疏林分和未成林地中,除下部分位数高度外,其余高度、密度统计特征参数均与激光雷达点云相应参数无显著性差异,但密集匹配点云对幼树三维结构的刻画能力优于机载激光雷达点云。在森林调查监测中,无人机密集匹配点云可直接用于稀疏林分和未成林地的森林参数估测,在既有高精度DEM支持下可对密集林分的一些林分参数(如冠层表面高度等)进行估测。

关键词: 点云, 密集匹配, 无人机, 激光雷达, 林分密度, 森林资源调查

Abstract:

In order to analyze the similarities and differences between the UAV dense matching point cloud and the airborne LiDAR point cloud,the spatial distribution of two kinds of point clouds for dense forest(canopy density of 0.85),sparse forest(canopy density of 0.55) and undeveloped forest was visually analyzed.The densely matched point cloud was normalize through two types of DEM(UAV_DEM and LiDAR_DEM) produced by UAV and LiDAR point clouds respectively.Then,the statistical characteristics of the obtained two sets of normalized densely matched point cloud data and LiDAR point cloud data were compared using the paired sample t-test analysis.The results show that:1) In dense forests,densely matched point cloud has great limitations to obtain canopy internal and ground information.After normalization using LiDAR_DEM,the densely matched point cloud and the laser point cloud were examined with significant differences in the middle and lower quantile heights and all density characteristics(α=0.05),while no significant differences found in the middle and upper quantile heights;2) In sparse forest and undeveloped forest,except for the lower quantile height,the remaining statistical parameters of height and density are not significantly different between the densely matched point cloud and the laser point cloud.However,the densely matched point cloud is superior to the airborne LiDAR point cloud regarding the ability of describing the three-dimensional structure of young trees.In conclusion,the UVA dense matching point cloud can be directly used to estimate the forest parameters of sparse forest and undeveloped forest in the forest survey and monitoring.With the assistance of high-precision DEM,some parameters of dense forest(e.g.,crown layer height) can be further estimated through the UVA dense matching point cloud.

Key words: point cloud, dense matching, Unmanned Aerial Vehicle, LiDAR, stand density, forest inventory

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