Semi-direct tree reconstruction using terrestrial LiDAR point cloud data
Semi-direct tree reconstruction using terrestrial LiDAR point cloud data
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DOI：
10.1016/j.rse.2018.02.013
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发表时间：
2018-04
影响因子：
13.5
通讯作者：
B. Bailey;M. Ochoa
中科院分区：
文献类型：
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作者：
B. Bailey;M. Ochoa
提出了一种利用陆地激光雷达数据在叶尺度上重建树木等大型植物几何结构的新方法。这项工作的主要目标是开发一种可行的方法，准确和快速地重建或“数字化”整棵树，以便在为高分辨率生物物理模型或分析提供几何输入的数字树模型中指定每一片叶子的位置、方向和大小。与任何光学测量技术一样，主要的挑战是准确计算传感器看不到的植物物质。由于本方法使用三角测量过程来近似地直接重建扫描仪观察到的尽可能多的树叶，因此该方法被称为“半直接”。对于遮挡视线的植物物质，使用统计回填过程添加额外的叶子，使重建的植株的叶面积和方向的三维分布与实际植株的平均匹配。在最好的情况下，例如当叶密度低时，几乎所有的叶面积都从扫描中直接重建，并且在重建中保留分枝和聚集结构。在最坏的情况下，例如当叶片密度很高并且几乎所有叶片都被遮挡在扫描仪的视野中时，只有一小部分叶片可以直接重建，但至少重建植株上的叶面积分布和叶片角度分布将与实际植株一致。与许多其他方法不同，本方法不依赖于植物的木质物质来提供重建的骨架，并且可以用于从扫描仪中几乎看不到木质物质的密集植物中。
A new method was developed for reconstructing the geometric structure of large plants such as trees at the leaf-scale by utilizing terrestrial LiDAR data. The primary goal of the work was to develop a feasible means for accurately and rapidly reconstructing or “digitizing” entire trees in order to specify the position, orientation, and size of every leaf in digital tree models that provide geometric inputs for high-resolution biophysical models or analyses. As with any optical measurement technique, a primary challenge is accurately accounting for plant matter that is occluded from view of the sensor. The present method is termed “semi-direct” because it uses a triangulation procedure to approximately directly reconstruct as many leaves as possible that are in view of the scanner. For plant matter obstructed from view, a statistical backfilling procedure was used to add additional leaves such that the three-dimensional distribution of leaf area and orientation of the reconstructed plant matched that of the actual plant on average. In a best case scenario such as when leaf density is low, nearly all leaf area is directly reconstructed from the scan and the branch and clumping structure is preserved within the reconstruction. In the worst case scenario such as when the leaf density is very high and nearly all leaves are occluded from view of the scanner, only a small fraction of leaves can be directly reconstructed, but at a minimum the distribution of leaf area and the leaf angle distribution across the reconstructed plant will be consistent with that of the actual plant. Unlike many other approaches, the present method does not rely on the woody matter of the plant to provide a skeleton for reconstruction, and can be used in dense plants where little woody matter is visible from the scanner.