Print Email Facebook Twitter Detection of harvested trees in forests from repeated high density airborne laser scanning Title Detection of harvested trees in forests from repeated high density airborne laser scanning Author Pietrzyk, Peter (Student TU Delft) Lindenbergh, R.C. (TU Delft Optical and Laser Remote Sensing) Date 2014-05-28 Abstract Identification of harvested and fallen trees is a prerequisite for the detection and measurement of changes in forests. This paper presents a three step approach to monitor harvested and fallen trees based on direct comparison of repeated high density airborne LIDAR data. In a first step differences between data sets are obtained from a point to point comparison, such that the data can be reduced to the deviating points only. Secondly, the resulting points are clustered into spatially connected regions using region growing. Finally, individual trees are extracted from the clusters by analysing their relative proximity and by analysing geometric properties of points in the clusters. Two data sets, acquired at a four year interval and covering a forest with mainly deciduous trees, are compared. First results show that most points relating to a change can be extracted and that clustering of these with region growing enables us to efficiently separate harvested and fallen trees from the remaining trees. Grouped harvested trees could not be separated using the region growing approach due to touching crowns. Segmentation of these using spectral clustering however identified individual regions well, but the results depend mainly on the pre-defined number of clusters. Crowns of grouped trees can be therefore separated if the number of trees is known. Subject Change detectionForestryLaser scanningLIDARMonitoringSegmentation To reference this document use: http://resolver.tudelft.nl/uuid:5c2e515b-6c2d-4d4e-ba95-4b88d3d62519 DOI https://doi.org/10.5194/isprsannals-II-5-275-2014 ISSN 2194-9042 Source ISPRS Annals of Photogrammetry, Remote Sensing and Spatial Information Sciences, 2 (5), 275-280 Event ISPRS Technical Commission V Symposium, 2014-06-23 → 2014-06-25, Riva del Garda, Italy Part of collection Institutional Repository Document type journal article Rights © 2014 Peter Pietrzyk, R.C. Lindenbergh Files PDF isprsannals_II_5_275_2014.pdf 1.63 MB Close viewer /islandora/object/uuid:5c2e515b-6c2d-4d4e-ba95-4b88d3d62519/datastream/OBJ/view