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STUDY ON APPLICATION OF THREE-DIMENSIONAL LASER SCANNING IMAGING 
SYSTEM IN TREE MEASURING 
L. L. Wu a ’ *, Z. K. Feng 3 , X. Luo b , X.R.Deng b 
3 Institute of GIS, RS & GPS, Beijing Forestry University, 100083 Beijing, P. R. China - (wll566577, 
fengzhongke)@ 126.com 
b China National Institute of Metrology, 100013, Beijing, P.R.China - (hslx9900, tangshandxr)@163.com 
KEY WORDS: Forestry, Surveying, laser scanning, Precision, Three-dimensional, Modelling 
ABSTRACT: 
In this paper, 3-D laser scanning imaging system was introduced to forestry measurement for data collection. Then the paper 
discussed the method for stand volume measure and crown measure by the new equipment. There are three methods to measure the 
stand volumes: using cylindrical and truncated cones to model the tree stem, collecting the point clouds of the tree stem to produce 
the surface of the stem to calculate volumes, the method of subsection integration to estimate the tree volume. Different methods fit 
to different trees with different shapes. In the measurement of stand crown volume, there are two methods to get the 3D models of 
the crown. The first is based on the point cloud data; the other method is to take the whole crown of the single tree as the 
components of the single small truncated cones. The method of using 3-D laser scanning imaging system could replace the 
traditional one in forestry was first to discuss. In experiment, 15 trees was selected to prove that 3-D laser scanning imaging system 
can be used in diameter breast height and tree height measurement. In stand volume estimation, the scanning system compared 
traditional sectional measurement method also showed high precision. 
1. INTRODUCTION 
The measurement science of forest is one of the basic subjects 
in the field of forestry, which studies on the forest itself and its 
products: timber, including the measurement, estimation and 
calculation(FENG Zhong ke, 2005; FAN Hai ying, 2004). In 
order to obtain the accurate measurement materials of the forest, 
the advanced measurement technology should be used because 
of the huge volumes and various shapes of the trees as well as 
the overlaps between the trees, which cause the difficulty to the 
work (ZHENG De hua, 2005; MA Li guang, 2005). The 
traditional method, wasting the resources and damaging the 
environment, is complicated, heavy-work loaded and needs 
cutting many trees. In a sense, it is not a preferred method. 
So, in this paper, a new research has been done, which used the 
model to realize the automation and explored the feasibility of 
using the data from standing trees got by scanning replacing the 
data got from fallen trunks. The data got by the traditional 
measuring tools are single and of low efficiency, which give 
certain restriction to the model construction based on the data 
and other analysis (FAN Hai ying, 2004). On the contrary, 3-D 
laser scanning imaging system can show the models of standing 
trees (MAO Fang-ru, 2005). Therefore, more comprehensive 
measurement values can be provided to make as the reliable 
data basis for the study of trunks, shapes of crowns, volumes 
and biomass. What’s more, the new method can set a 
foundation for the dynamic monitoring of forest resources. 
The purpose of the research was to have a exploratory study on 
the data collection method of using 3-D laser scanning imaging 
system to enrich the traditional measurement method, as well as 
the theory of forest measurement. 
2. METHODS OF STANDING TREES VOLUME 
MEASUREMENT AND STAND CROWN 
MEASUREMENT 
2.1 Measurement of standing trees’ scanning volume 
The traditional sectional measurement of fallen trunks is like 
this: cutting down the standing trees and measuring the exact 
volume by method of subsection integration to estimate the 
tree volume. As for the scanning data, with the help of the 
coordinate matching function provided by the corresponding 
software of the 3-D laser (Cyclone) scanning imaging system, 
a whole point cloud model of a standard tree was got by the 
patching of the point cloud data. After the processing of data 
merging, rejecting the gross errors, automated segment 
extraction and TIN model structure, the details of sample trees 
will be modelled and finally get the 3-D models of the whole 
trees. The models can be rotated, translated, zoomed and 
angle-changed to measure the direct measuring factors like 
diameters (including the segment diameters), height and crown 
of the standing trees directly and conveniently. Then, trunk 
volume was got (ZHENG De-hua. 2005). 
There are three methods of volume measurement using 3-D 
laser scanning imaging system. They are as follows: 
2.1.1 Using cylindrical and truncated cones to model the tree 
stem 
The calculation function of Cyclone software is used to 
calculate the exterior area and volume of the trunks (See below 
in Fig. 5). This method is suitable for the tree species with the 
shape of cylindrical, like pine trees and large birches. The 
advantages of this method is with great manoeuvrability and 
can compensate for point cloud data loss caused by equipment 
operation environment. As long as the value of point cloud 
* Corresponding author.