Publications in Scientific Journals:

M. Hollaus, W. Wagner, C Eberhöfer, W. Karel:
"Accuracy of large-scale canopy heights derived from LIDAR data under operational constraints in a complex alpine environment";
ISPRS Journal of Photogrammetry and Remote Sensing, 60 (2006), 323 - 338.

English abstract:
Airborne laser scanning (ALS) is currently one of the most promising remote sensing techniques for quantitative retrieval of
forest parameters. While ALS has reached an operational status for mapping of boreal forests, its large area application over
mountainous environments is lacking behind. This is because alpine forests often have high horizontal and vertical structural
diversity and are situated in steep terrain. Also, ALS data acquisition and processing is more demanding over mountainous areas
than over relatively flat regions.
In this study we have used state-of-the-art ALS technology and software packages to map canopy heights and to estimate tree
heights for a 128 km2 region in the western part of the Austrian Alps. Spruce and fir are the dominant tree species. Rather than
employing data and methods tuned for a particular task and for a small study area, we solely use data and methods which already
serve other operational applications. Thus, it is ensured that the results obtained in this study are of practical relevance.
For the validation of the ALS derived canopy heights we have used 22000 ground control points and field-measured forest
inventory data from 103 sample plots, which are operationally used by the local forest administration. The validation of the digital
terrain model (DTM) with the ground control points shows that over non-forested terrain DTM errors increase from 10 cm for
relatively flat terrain (local slope<10°) to over 50 cm for local slopes greater than about 60°. The validations of the ALS derived
single-tree heights and Lorey's mean heights show good correlations using both, three dimensional first pulse points (R2=0.73-
0.84) and a grid-based canopy height model (R2=0.68-0.87). Overall, the results demonstrate that airborne laser scanning has now
reached the maturity to be used for mapping canopy heights of complex alpine forests throughout large areas.

Alpine forest; LiDAR; Canopy height; DTM; Forest inventory

Online library catalogue of the TU Vienna:

Related Projects:
Project Head Wolfgang Wagner:
Christian Doppler Labor für Räumliche Daten aus Laserscanning und Fernerkundung 2005

Project Head Wolfgang Wagner:

Created from the Publication Database of the Vienna University of Technology.