ALS/Drone Individual Tree Crown Representations

This repository contains multi-temporal point cloud and convex hull representations of 110 indiviual tree crowns. This ALS data was captured within the Malcolm Knapp Research Forest, located 60 km east of Vancouver, Canada (49.26°N, -122.56°E) and is predominantly composed of productive coniferous species, primarily Douglas-fir (Pseudotsuga menziesii), and western hemlock (Tsuga heterophylla). Crowns are indexed by a unique 'tree_id' with T1 reffering to the first capture in 2016 from fixed wing aircraft and T2 in 2022 from DJI Matrice 300 quadcoptor drone. The main directories contain: '01_tree_pairs': Subdirectories labeled by unique tree id. The prefixes within the naming structure of files with the subdirectories refer to: '01' are the two vertex matched crown hulls, '02' the predicted crown stem line, '03' the filtered and density normalised point clouds, '04' the reprojected icosphere used to map and match a datum of vertices, and '05' the original alpha-shape mesh. '02_projected_crown_mesh': This directory contains the predicted convex hulls of tree crows derived from the approach outlined in the associated publication.本仓库包含110株单棵树冠的多时序点云（multi-temporal point cloud）与凸包（convex hull）表征数据。本次采集的机载激光扫描（Airborne Laser Scanning, ALS）数据位于加拿大温哥华以东60公里处的马尔科姆·纳普研究林（49.26°N, -122.56°E），林分以丰产针叶树种为主，主要为花旗松（Pseudotsuga menziesii）与西部铁杉（Tsuga heterophylla）。所有树冠通过唯一标识符'tree_id'进行索引，其中T1代表2016年通过固定翼飞机采集的首轮数据，T2代表2022年通过DJI Matrice 300四旋翼无人机采集的二次数据。 主目录包含以下内容： '01_tree_pairs'： 子目录以唯一树号命名。子目录内文件命名结构中的前缀含义如下：前缀'01'对应两组顶点匹配的树冠凸包，'02'对应预测的树冠树干轴线，'03'对应经滤波与密度归一化处理的点云，'04'对应用于映射与匹配顶点基准的重投影二十面体网格（icosphere），'05'对应原始alpha形状网格（alpha-shape mesh）。 '02_projected_crown_mesh'： 该目录包含基于相关论文所述方法得到的预测树冠凸包数据。