Terrestrial Scanning / Forestry Assessment & Agriculture
A. Bienert, H.-G. Maas, S. Scheller "Analysis of the Information Content of Terrestrial Laserscanner Point Clouds for the Automatic Determination of forest Inventory Parameters" 07.01.2009
Terrestrial laserscanners find rapidly growing interest in photogrammetry as efficient tools for fast and reliable 3D point cloud data acquisition. They have opened a wide range of application fields within a rather short period of time. Beyond interactive measurement in 3D point clouds, techniques for the automatic detection of objects and the determination of geometric parameters form a high priority research issue. The quality of 3D point clouds generated by laserscanners and the automation potential make terrestrial laserscanning also an interesting tool for forest inventory.
The paper will first review current laserscanner systems from a technological point of view and discuss different scanner technologies and system parameters regarding their suitability for forestry applications. In the second part of the paper, results of a pilot study on the applicability of terrestrial laserscanners in forest inventory tasks will be presented. The study concentrates on the automatic detection of trees and the subsequent determination of tree height and breast height diameter.
Reliability and precision of techniques for automatic point cloud processing were analysed based on scans of a test region in a Saxonian mixed forest. In the pilot study, which represents an early stage of software development, more than 95% of the trees in a test region could be detected correctly. Tree heights could be determined with a precision of 80 cm, and breast height diameters could be determined with a precision of less than 1.5 cm.