Lidar point clouds of three oak trees
Data files
Jan 13, 2026 version files 363.31 MB
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Bigoak_M_P1.xyz
33.70 MB
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Bigoak_M_P2.xyz
31.24 MB
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Bigoak_M_P3.xyz
28.99 MB
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Bigoak_M_P4.xyz
23.66 MB
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Bigoak_M_P5.xyz
26.68 MB
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Bigoak_M_P6.xyz
23.46 MB
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Mediumoak_M_P1.xyz
24.57 MB
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Mediumoak_M_P2.xyz
21.29 MB
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Mediumoak_M_P3.xyz
18.97 MB
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Mediumoak_M_P4.xyz
17.66 MB
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Mediumoak_M_P5.xyz
21.80 MB
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Mediumoak_M_P6.xyz
22.04 MB
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README.md
795 B
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Smalloak_M_P1.xyz
13.06 MB
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Smalloak_M_P2.xyz
12.77 MB
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Smalloak_M_P3.xyz
11.51 MB
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Smalloak_M_P4.xyz
10.24 MB
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Smalloak_M_P5.xyz
10.51 MB
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Smalloak_M_P6.xyz
11.16 MB
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TLS_positions_Big_Oak.txt
176 B
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TLS_positions_Medium_Oak.txt
178 B
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TLS_positions_Small_Oak.txt
182 B
Abstract
The data consists of a 3-dimensional point cloud of trees produced by a laser scanner, where each point is a sample of the tree’s surface. As for a single scanner location, a large part of the tree is occluded, multiple scans are commonly performed, and their data are co-registered (Li et al., 2020; Raumonen et al., 2015; Wan et al., 2019). It is important to not only place the points in a consistent coordinate scheme during co-registration, but also the scanner locations and to keep track of which points were produced by which scanner location for uncertainty propagation. To showcase our methodology, we applied it to terrestrial laser scanning data of 80-year-old oak trees of three different sizes (small, medium, and large). The raw point clouds were recorded at Alice Holt Forest, UK (51.1546°N, 0.8520°W) using a single-return phase shift Leica HDS- 6100 terrestrial laser scanner (Leica Geosystems, n.d.). The scans were conducted in March 2014 under dry conditions and low wind speeds (less than 2 m/s). Point clouds were acquired from six scan positions around each tree (azimuth angle: 0°, 60°, 120°, 180°, 240°, and 300°), each located 5 m from the tree base and 1.3 m above ground level. The TLS angular sampling resolution was 0.036° at each scan position, with a laser beam characterized by a 0.003 m spot size at exit, a divergence angle of about 0.013° (a 0.008 m spot size at 25 m, based on Gaussian definition). Detection and removal of scanner noise, multiple reflections, and ghost points were performed using a depth-discontinuity triangles-based method, which evaluates the angle between the local surface normal and the TLS viewing direction (Rombourg, 2019; Tang et al., 2007). The filtered point clouds were subsequently aligned within a common Cartesian coordinate system using Cyclone v9.0 (Leica Geosystems Ltd.), based on six ’6” tilt-and-turn’ reflective planar targets (Leica Geosystems Ltd.) positioned around each tree.
Data is provided on behalf of Forest Research UK.
Dataset DOI: 10.5061/dryad.7h44j1086
Description of the data
Files and variables
TLS scanner locations are given in TLS_Positions_*_Oak.txt with format
x y z #scanner
For each tree, there are six scanner locations, each of which has a point cloud stored in an .xyz file (i.e. Bigoak_M_P1 for the first scanner location for the big tree) with format
x y z
Code/software
The following Matlab code was used to read the data (Data_Processing/EC_Data_Reader.m) and used to fit QSMs to it with TreeQSM 2.4.1 and quantify their uncertainty.
