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Research article2004Peer reviewed

Rewiew article, Laser scanning of forest resources: the nordic experience

Erik Naesset, Terje Gobakken, Hannu Hyyppä, Juha Hyyppä, Matti Maltamo, Åsa Persson, Ulf Söderman, Holmgren Johan, Nilsson Mats, Olsson Håkan

Abstract

This article review the research and application of airborne laser scanning for forest inventory in Finland, Norway and Sweden. The first experiments with scanning lasers for forest inventory were conducted in 1991 using the FLASH system, a full waveform experimental laser developed by the Swedish Defence Research Institute. In Finland at the same time, the HUTSCAT profiling radar provided experiences that inspired the following laser scanning research. Since 1995, data from commercial operated time-of-flight scanning lasers (e.g. TopEye, Optech ALTM and TopoSys) have been used. Especially in Norway, the main objective has been to develop methods that are directly suitable for practical forest inventory at the stand level. Mean tree height, stand volume and basal area have been the most important mensurational parameters of interest. Laser data have been related to field training plots measurements using regression techniques, and these relationships have been used to predict corresponding properties in all forest stands of the area. Experiences from Finland, Norway and Sweden show that retrieval of stem volume and mean tree height at stand level from laser scanner data performs as well as, or better than, photogrammetric methods, and better than other remote sensing methods. Laser scanning is, therefore, now beginning to be used operationally in large-area forest inventories. In Finland and Sweden, research has also been done into the identification of single trees and estimation of single- tree properties, such as tree position, tree height, crown width, stem diameter and tree species. In coniferous stands, up to 90% of the trees represented by stem volume have been correctly identified from canopy height models, and the tree height has been estimated with a root mean square error around 0.6 m. It is significantly more difficult to identify suppressed trees than dominant trees. Spruce and pine have been discriminated on a single-tree level with 95% accuracy. The application of densely sampled laser scanner data to change detection, such as growth and cutting, has been demonstrated

Keywords

Airborne laser scanning; canopy height; forest inventory; timber volume; tree segmentation

Published in

Scandinavian Journal of Forest Research
2004, Volume: 19, number: 6, pages: 482-499 Publisher: Taylor & Francis group