Forest in situ observations using unmanned aerial vehicle as an alternative of terrestrial measurements
Forest in situ observations using unmanned aerial vehicle as an alternative of terrestrial measurements
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DOI：
10.1186/s40663-019-0173-3
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发表时间：
2019-04-15
影响因子：
4.1
通讯作者：
Deng, Songqiu
中科院分区：
文献类型：
--
作者：
Liang, Xinlian;Wang, Yunsheng;Deng, Songqiu
背景：近年来，陆地点云作为一种新的森林调查数据源引起了人们的关注。到目前为止，就几何精度和细节水平而言，陆地激光扫描(TLS)是所有陆地点云数据中数据质量最高的(IEEE Transact Geosi Remote Sens 53：5117-5132,2015)。在实际应用中，经过自动算法处理的TLS点云能够以接近所需的精度提供特定的个体树参数。然而，所有的陆地点云都面临着一个普遍的挑战，那就是上层树冠的遮挡。一种名为无人机载激光扫描(ULS)的新兴技术可能结合了林冠上和林下调查的优点。结果：在北方森林中，对22个不同林分条件的样地进行了ULS的性能评估。森林参数估计是通过与静态地面和移动激光扫描的最先进的地面机制进行比较来确定基准的。结果表明，在易林分条件下，ULS点云的性能与地面解相当。结论：本研究首次对ULS在不同森林条件下的现场观测进行了严格的评估。这项研究还可作为现有主动遥感技术用于森林现场测量的基准。结果表明，现有的ULS具有良好的树高/树冠测量性能。尽管ULS数据的几何精度，特别是树干部分的几何精度还没有达到其他陆地点云的水平，但无与伦比的高流动性和快速的数据获取使ULS成为森林调查中一个非常有吸引力的选择。
Background: Lately, terrestrial point clouds have drawn attention as a new data source for in situ forest investigations. So far, terrestrial laser scanning (TLS) has the highest data quality among all terrestrial point cloud data in terms of geometric accuracy and level of detail (IEEE Transact Geosci Remote Sens 53: 5117-5132, 2015). The TLS point clouds processed by automated algorithms can provide certain individual tree parameters at close to required accuracy in practical applications. However, all terrestrial point clouds face a general challenge, which is the occlusions of upper tree crowns. An emerging technology called unmanned-aerial-vehicle (UAV) - borne laser scanning (ULS) potentially combines the strengths of above and under canopy surveys.Results: The performance of ULS are evaluated in 22 sample plots of various forest stand conditions in a boreal forest. The forest parameter estimates are benchmarked through a comparison with state-of-the-art terrestrial mechanisms from both static terrestrial and mobile laser scanning. The results show that in easy forest stand conditions, the performance of ULS point cloud is comparable with the terrestrial solutions.Conclusions: This study gives the first strict evaluation of ULS in situ observations in varied forest conditions. The study also acts as a benchmarking of available active remote sensing techniques for forest in situ mensuration. The results indicate that the current off-the-shelf ULS has an excellent tree height/tops measurement performance. Although the geometrical accuracy of the ULS data, especially at the stem parts, does not yet reach the level of other terrestrial point clouds, the unbeatable high mobility and fast data acquisition make the ULS a very attractive option in forest investigations.