Terrestrial Laser Scanning Point Clouds and Tree Attributes from 55 Sample Plots at the Evo Test Site (Spring 2024)

Abstract

Terrestrial laser scanning data acquired from 55 sample plots (32 m × 32 m) in Evo, Southern Finland during April 22 to May 14, 2024 (leaf-off conditions) using a Riegl VZ-400i terrestrial laser scanner with following configuration:

Acquisition Dates: 22 April – 14 May 2024 Conditions: Leaf-off Scanner Model: Riegl VZ-400i Measurement principle: Time-of-flight Wavelength: 1550 nm Laser Beam Diameter (at exit): 7 mm Beam Divergence: 0.35 mrad (at the 1/e² points) Beam Diameter at 10, 20 and 30 m: 10, 14, 18 mm Pulse Repetition Rate: 600 kHz Maximum Returns per Pulse: Up to 8 Scan Pattern: ‘Panorama 40’ Angular Resolution: 0.04° Point Spacing at 10 m: 3.5 mm Vertical Field of View: 100° (Scan Position, upright), 360° (Scanner tilted 90°) Horizontal Field of View: 360° (Scan Position, upright), 100° (Scanner tilted 90°)

The data was processed in the RiSCAN PRO software (version 2.19.3) where the built-in LIS TreeAnalyzer plugin, developed by Laserdata GmbH, was utilized for identifying and segmenting individual trees and measuring their characteristics.

For each sample plot (n = 55), a point cloud file (.laz) is provided with the following attributes for each point record: - X coordinate (Easting) [m], ETRS-TM35FIN (epsg: 3067) - Y coordinate (Northing) [m], ETRS-TM35FIN (epsg: 3067) - Z coordinate (Height) [m], N2000 - Reflectance (distance-corrected intensity) [dB] - Return number - Return count - Point Cloud ID (scan position ID) - Height above ground level [m] - Tree ID number

In addition, a text file is provided, containing the following attributes for each segmented tree (n = 6320): - X coordinate of stem cross section mid-point (Easting) [m], ETRS-TM35FIN (epsg: 3067) - Y coordinate of stem cross section mid-point (Northing) [m], ETRS-TM35FIN (epsg: 3067) - Z coordinate of stem cross section height [m], N2000 - Sample plot ID number - Tree ID number - Circle completeness (related to Hough circle finding for tree identification) - Crown projection area [m2] - Crown diameter [m] - Stem diameter measured at the height of tree identification [m] - Goodness of fit (related to Hough circle finding for tree identification) - Height of the point cloud slice used for tree identification [m]