期刊名称：ISPRS Annals of the Photogrammetry, Remote Sensing and Spatial Information Sciences
印刷版ISSN：2194-9042
电子版ISSN：2194-9050
出版年度：2004
卷号：XXXV Part B2
页码：84-90
出版社：Copernicus Publications
摘要：Ecological analysis and forest planning need sophisticated information about the structures of forests. In recent years new sensor systems like laserscanner and digital airborne cameras emerged on the marked which fulfil the high requirements for forest applications. Also, new methods for automated delineation and feature extraction of individual trees have been developed. In this study images of the brand-new Digital Modular Camera were used to automatically generate a DSM by image matching techniques. The resulting density of matched 3D points was 18 pts/m 2 . After the robust filtering the cleaned point cloud showed a mean density of 11 pts/m 2 . The photogrammetric DSM was subsequently compared to a manual stereoscopic measurements and ground surveys. Tree height measurements from stereoscopic measurements showed a better accuracy than heights derived from laserscanning DSM and the photogrammetric DSM. The applied method of DSM generation using a feature-based matching approach could successfully reconstruct deciduous canopy surfaces with almost the same accuracy as the laser scanner did. However, the method failed especially when single coniferous trees were present in the plot by cutting the tree tops and underestimating the lower areas between the trees. Several ways to improve the matching strategy of the present algorithm for canopy reconstruction are discussed. The potential of the photogrammetric and laserscanner DSM`s for automated tree detection could be clearly shown by applying a single tree delineation algorithm which is based on a watershed approach
关键词：Forestry; DEM/DTM; Laser Scanner; Digital Imagery; Individual Tree Detection
