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M. Hollaus, W. Dorigo, W. Wagner, K. Schadauer, B. Maier:
"Large-area stem volume estimation based on airborne laser scanner data and national forest inventory data";
Talk: ForestSAT07, Montpellier; 2007-11-05 - 2007-11-07; in: "Proceedings of the ForestSAT07", (2007), 5 pages.

The objective of this paper is to evaluate a new approach for the estimation of stem volume based on ALS data. The approach was tested for the entire Vorarlberg province in Austria, which covers about 97,000 ha of forests. ALS data were acquired in the framework of a commercial district-wide terrain mapping project and were acquired during several winter- and summer flight-campaigns. The laser point density varies between 1 and 4 points/m². The pre-processing of the ALS data was performed with state-of-the-art methods and commercially available software packages. A novel linear model was employed, which describes the stem volume as a linear function of canopy volume. The canopy volume is defined by the volume between the terrain surface and the canopy surface derived from the first-echo hits. The calibration of the stem volume model was based on national forest inventory (NFI) data. The first results of this approach provided a maximum R² of 0.69 and a standard deviation (SD) of residuals derived from cross-validation of 129.9 m³/ha (34.6%). A stratification of the forest into coniferous, mixed and deciduous forests increased the achieved accuracies (e.g. R² = 0.78; SD = 110.9 m³/ha (29.0%) for coniferous forests). As all involved data sources are in operational use, it is ensured that the results obtained in this study are relevant for forest and environment policy and practical applications.

LIDAR, linear model, downscaling, mountainous forest

http://publik.tuwien.ac.at/files/pub-geo_2023.pdf

Project Head Wolfgang Wagner:
Christian Doppler Labor für Räumliche Daten aus Laserscanning und Fernerkundung 2007

Project Head Wolfgang Wagner:
Regionalisierung von Waldinventurdaten mit Hilfe von Methoden des luftgestützten Laserscannings