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Conference paper2008Peer reviewed

Estimation of tree lists from airborne laser scanning data using a combination of analysis on single tree and raster cell level

Lindberg, Eva; Holmgren, Johan; Olofsson, Kenneth; Olsson, Håkan; Wallerman, Jörgen

Abstract

Airborne laser scanning produces high resolution data which opens up for estimation methods on individual tree level. However, the detection rate depends on the forest structure, and typically suppressed trees below a dominant tree layer are not detected. This paper presents a method to produce tree lists consistent with unbiased estimates on raster cell level. First, automatic delineation of tree crown segments was performed. The number and attributes of trees were estimated within segments. Second, forest variables were estimated on a field plot level using both laser canopy height distribution and results from tree detection. Percentiles of the stem diameter and tree height distributions were estimated using regression models. Third, the estimated percentiles were used as input for imputation of field trees from similar field plots in order to create a target distribution matrix. The number of trees in this matrix was estimated by scaling with the estimated total volume for each field plot. Finally, the initial tree list obtained from the tree crown segmentation was adjusted by using the estimated target distribution matrix. Random errors and bias for stem volume and stem number estimates could be reduced by combining analysis on tree and raster cell level

Keywords

Lidar; single tree; area based; tree list; diameter distribution

ISBN: 978-0-85538-774-7

Conference

SilviLaser 2008