Evaluation of LIDAR and Photogrammetric Elevation Data for Feature-based Forest Analyses [article]

S. Mohsen Miri, Universitätsbibliothek Der FU Berlin, Universitätsbibliothek Der FU Berlin
2016
For qualitative and quantitative detection of forest resources, there is a demand to extract the stand parameters in forestry not only at stand level but also for single trees; high resolution digital surface models may be suitable for this aim. The dependence of most of stand features on tree height, demonstrates the importance of this element in the characterisation of forest stands from an environmental perspective and for the purpose of the timber industry. Airborne laser point clouds and
more » ... otogrammetric stereo images are the two main data acquisition sources to generate the digital surface models for detailed and large areas of forests. The main aim of this research is to study these two surface models for feature extraction approaches based on height data. In the represented research neither the spectral information of the images nor the intensity values of the LIDAR data are used. For this purpose a novel concept, called eye-finger, is developed to simulate and analyze the surface models by touching the top levels of the tree crown with closed eyes. To translate the feeling of the human sense of touch into the language of machine vision, the geometric and morphological features are defined and evaluated on both laser-based and image-based canopy height models. Because of the high degree of noise in the laser data, a filter should be implemented before the comparison and the segmentation steps. The developed non-smoothing filter in this work removes the problematic pixels, while the roughness and the form of the trees remain unchanged. The work focuses on European mixed-forests, consisting of coniferous and deciduous trees. The roughness parameters used in the production industry are implemented to extract the surface characteristics of mixed-forests. The average-based parameters like Ra show the dependency of these surface evaluators on the age and tree type of the stand. The roughness parameters related to the standard deviation of the surface, measure the finer variations on the surface. An advanced roug [...]
doi:10.17169/refubium-17690 fatcat:o447hdj7hffenndjbs4zyp7cwq