nbul 2004 
(5) 
es for the 
or the two. 
formation 
formation 
Therefore, 
property 
tance. | 
1 the same 
en it was 
(7) 
e allowed, 
minimum 
olves the 
| for the 
based on 
al surface 
y a laser- 
| parts of 
generated 
ure taken 
at corner 
on of the 
r data is 
n used to 
ters. The 
ig as the 
'ed image 
1e virtual 
y used for 
fragments 
er model 
r-scanner 
International Archives of the Photogrammetry, Remote Sensing 
model is transparent and the damages not, one can distinguish 
which fragments are sticking out and which do not. Otherwise 
the user had the impression that all fragments were flying in 
front of the building. 
In figure 8. an example for the polygon method is displayed. 
Two polygons have been digitised that should describe the 
corner of the building. The red dots are the points on the blue 
rays established by measured image points and the projection 
centres. The red points are connected by red lines and define 
like that the polygons. For each measured bundle of rays one 
obtains a polygon. The image shows the two polygons. Due to a 
height error of the GPS receiver the left polygon is measured 
too low. This creates an accordion effect for both reconstructed 
polygons. This effect could be avoided, if more than two 
polygons would be digitised to measure the polygon and an 
unknown free mean polygon is determined by minimising the 
sum of distances from the mean polygon to all measured 
polygons. 
  
Figure 4. Laser data of the studied building. 
and Spatial Information Sciences, Vol XXX V, Part B3. Istanbul 2004 
  
Figure 5. Video image 
Figure 7. Mixture of the laser-scanner data, the video and the 
simulated damages 
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