Parameterized Tree Positions Dresden 2017

The parameterized tree positions represent the location of all trees detected on the basis of a laser scan survey from 2017 within the City of Dresden (Germany). Geometric attributes such as tree height and crown diameter were derived for each tree. For this purpose, the urban forest was classified in the point cloud and then individual tree crowns were segmented. Based on these segments, geometric attributes were determined from the LiDAR point cloud. In total, this automated inventory contains ~ 3 million tree positions. This is an overestimation of the actual number of trees which is due to inaccuracies in the segmentation of individual trees, especially in dense tree stands. Despite this overestimation, the tree volumes detected in the point cloud are realistically reproduced. The methodology is described in detail in this article. Each tree has the following attributes: "treeID_utm33_tiles" - ID "H_Tree" – tree height (m) "H_Crown" – crown height (m) "H_Trunk" – trunk height (m) "D_Crown" – crown diameter (m) "X", "Y","Z" – position The dataset is available either as a Shapefile or GeoJSON in the coordinate system ETRS89/UTM zone 33 (EPSG: 25833). The dataset was divided into tiles. The tile number results from the coordinate of the lower left corner in the coordinate reference system. The source data used was made freely available by the “Landesamt für Geobasisinformation Sachsen” (GeoSN) under the license "Data license Germany - attribution - Version 2.0" and can be downloaded under the following links: LiDAR: https://www.geodaten.sachsen.de/downloadbereich-digitale-hoehenmodelle-4851.html 3D Building Model: https://www.geodaten.sachsen.de/downloadbereich-digitale-3d-stadtmodelle-4875.html Aerial Imagery: https://www.geodaten.sachsen.de/downloadbereich-dop-4826.html

经参数化处理的树木点位，代表2017年德国德累斯顿市激光扫描勘测中识别出的全部树木的空间位置。针对每棵树木，均提取了树高、冠幅直径等几何属性。为此，研究团队先对点云数据中的城市林木进行分类，再对单木树冠进行分割。基于上述分割结果，从激光雷达（LiDAR）点云中提取得到各类几何属性。本次自动化林木清查共得到约300万个树木点位。该点位数量存在一定高估，其原因在于单木分割环节存在误差，在林木密集区域尤为明显。尽管存在高估，但点云中识别出的树木体积仍能较为真实地反映实际情况。相关研究方法已在本文中进行详细阐述。

单木包含以下属性字段：
- treeID_utm33_tiles：树木唯一标识
- H_Tree：树高，单位为米（m）
- H_Crown：冠高，单位为米（m）
- H_Trunk：树干高度，单位为米（m）
- D_Crown：冠幅直径，单位为米（m）
- X、Y、Z：树木空间坐标

本数据集可采用Shapefile或GeoJSON格式发布，坐标系采用ETRS89/UTM第33带（EPSG: 25833）。数据集已按瓦片进行切分，瓦片编号由该瓦片在坐标系中的左下角坐标确定。

本数据集所用的源数据由萨克森州地理基础信息局（Landesamt für Geobasisinformation Sachsen，简称GeoSN）免费发布，采用"Data license Germany - attribution - Version 2.0"（德国数据许可-署名-2.0版）授权协议，相关源数据可通过以下链接下载：
- 激光雷达（LiDAR）数据：https://www.geodaten.sachsen.de/downloadbereich-digitale-hoehenmodelle-4851.html
- 三维建筑模型：https://www.geodaten.sachsen.de/downloadbereich-digitale-3d-stadtmodelle-4875.html
- 航空影像：https://www.geodaten.sachsen.de/downloadbereich-dop-4826.html