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Talks and Poster Presentations (with Proceedings-Entry):

L. Eysn, M. Hollaus, K. Schadauer, A. Roncat:
"Crown coverage calculation based on ALS data";
Talk: 11th International Conference on LiDAR Applications for Assessing Forest Ecosystems (Silvilaser 2011), Hobart, Australia; 2011-10-16 - 2011-10-20; in: "Silvilaser 2011", (2011), 10 pages.



English abstract:
The objective of this paper is to present and evaluate a new geometrically unambiguously
defined approach to calculate forest canopy cover, also known as crown coverage (CC) from
airborne laser scanning (ALS) data based on national forest inventory (NFI) data. The CC is
defined as the proportion of the forest floor covered by the vertical projection of the tree
crowns. Most forest definitions lack in precise geometrical definitions for the calculation of CC
and therefore, the results of common calculation methods differ and tend to be incomparable. To
demonstrate the effect of such an unclear defined, common CC calculation method, CC maps,
generated from moving window algorithms using different kernel shapes and sizes, are
calculated and analyzed for three study areas in Tyrol, Austria. The new unambiguously
approach, the tree triples method, is based on defining CC as a relation between the sum of the
crown areas of three neighbouring trees at a time and the area of their convex hull. The
approach is applied for the same study areas and is compared with forest masks that are
generated from moving window algorithms using different kernel shapes and sizes.

Keywords:
forest definition, canopy cover, forest border delineation, vegetation mapping, LiDAR


Electronic version of the publication:
http://publik.tuwien.ac.at/files/PubDat_202289.pdf


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