Schardt, Mathias 
  
FOREST INVENTORY BY MEANS OF SATELLITE REMOTE SENSING AND LASER SCANNING 
Andreas Wimmer; Mathias Schardt; Michaela Ziegler; Georg Ruppert; 
Klaus Granica; Ursula Schmitt; Heinz Gallaun? and Juha Hyyppà ! 
"Joanneum Research, Austria 
Institute for Digital Image Processing 
andreas.wimmer Q joanneum.ac.at 
fHelsinki University of Technology, Finnland 
Laboratory of Space Technology 
KEY WORDS: forest inventory, forest attributes, satellite imagery, laser scanning, stand-wise approach, single tree 
segmentation 
ABSTRACT 
In this paper forest inventory methods which are based on satellite remote sensing and laser-scanner data will be intro- 
duced. It will be demonstrated in how far conventional terrestrial inventories at a scale of 1 : 10.000 to 1 : 25.000 can 
benefit from the synergetic use of both sensor types. The forest inventory parameters to be investigated are: tree height, 
timber volume, tree species, tree age, stand border, and basal area. The presented results are mainly derived from the 
following projects 
— HIGHSCAN (Assessing forest stand attributes by integrated used of high-resolution satellite imagery and laser- 
scanner), EU - DG XII, CEO, co-ordinated by the Helsinki University of Technology and financed by the EU, 
— ALPMON (Inventory of alpine-relevant parameters for an alpine monitoring system using remote sensing data and 
GIS), EU - DG XII, CEO, co-ordinated by Joanneum Research Graz 
— SEMEFOR, Satellite based environmental monitoring of European forests, EU-DG XII, Pilot Projects, co-ordinated 
by Swedish Environmental Institute, Stockholm 
The projects are conducted in close co-operation with forest private and governmental management administrations. In 
this paper the results derived from different test sites will be presented. 
1 INTRODUCTION 
In the Austrian National Forests and those belonging to large forestry owners, forest inventories are performed every ten 
years on a stand-wise basis. In this inventories data are collected using cost-intensive field surveys in combination with 
yield tables. Inventory data for small forestry owners are mainly collected on the basis of questionnaires (Wood Felling 
Reports). Inventories of a similar intensity to those taken for the national forests and large forestry concerns are carried 
out only for those small forestry owners which have combined into agricultural associations. The proportion of small 
forestry owners participating in agricultural associations is very small, therefore field inventories are only carried to an 
very extensive extend. 
In this paper the potential of satellite remote sensing and laser-scanner data will be introduced and discussed. According 
to the positive experiences in the field of satellite based forest inventories it can be stated that satellite remote sensing is an 
appropriate tool to inventor and monitor forest parameters at a small scale. However, not all inventory relevant parameters 
such as tree height, tree volume, vertical stand structure and under-storage can directly be derived from satellite remote 
sensing. To overcome this shortcomings new airborne laser-scanner data from TOPOSYS can be used additionally to 
satellite images. Doing this, the synergetic use of both laser-scanner data and satellite data will take advantage of the 
benefit from both sensor types. 
Firstly, in this paper the potential of satellite remote sensing for the classification of forest parameters will be presented. 
Due to the lack of very high resolution the results will focus on the demonstration and evaluation of high resolution 
satellite data such as Thematic Mapper and SPOT IV data. Secondly, the ability to classify forest parameters by means of 
laser scanner data will be introduced. Finally, the information content of both data types will be compared and potential 
synergies outlined. 
  
1316 International Archives of Photogrammetry and Remote Sensing. Vol. XXXIII, Part B7. Amsterdam 2000. 
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