ement the Software 
2D the images were 
0 a given plane. This 
h the choice of two 
ured on the object 
r the rectification of 
ched together to an 
in a specific scale as 
ly. 
; could carry out the 
ric triangulation tool 
pending on the input 
ues such as space 
d a bundle block 
) define the variables 
mated digital surface 
ighly accurate point 
of a typical facade 
e of 1:450 and were 
image resolution of 
. coverage of 4.5 mm 
e was about 9 m, the 
re measured with an 
the chosen „natural“ 
;s manually, and the 
ate of the exterior 
nt collection — based 
amount of tie points 
d. 
  
point collection 
triangulation process 
of unit weight. The 
uals computed for the 
  
  
  
Property S.D. 
Ground X 0.0120 m 
Ground Y 0.0191m 
     
   
  
  
  
  
  
  
  
Ground Z 0.0130m 
Image X 0.2726 pixel ~ 3 um 
Image Y 0.2747pixel 
  
  
Figure 6: Results of the triangulation 
For the high accuracy orthophoto-production but also for the 
production of building-sections and in a long term for the 
production of a 3D model of the whole temple finally a digital 
elevation model of the facade was automatically generated with 
the help of the stereo-model. 
For the evaluation of the accuracy of the DEM a comparison 
between the known object points (tie- and ground control 
points) and the matched DEM-points was made. The absolute 
deviations varied between -4 and +3 cm. The average absolute 
error was about +/-1 cm. The maximum-faults occurred in the 
shadowed areas and could be corrected by simple editorial work 
with Erdas Stereo-Analyst. 
With the achieved data sections in any order could be laid 
through the facade by Profile Tools of Erdas Imaging. 
  
  
  
s 
Figure 7: Orthophoto, DGM and Profiles 
4. CONCLUSIONS 
The achieved methods of digital photogrammetry will be a solid 
component in archaeological and architectural work of the next 
Sirwäh-Expedition. The painful hand-made line drawing can be 
  
replaced in great parts. The image-maps as geometrically 
correct drawing-basis can be rationalized. The maps are at 
disposal within a day. During special training periods the 
archaeologists and architects are taught to help themselves with 
this technology. 
First results of point-matching to automatically generation of 
surface models show that a complete three-dimensional object 
reproduction by digital photogrammetric methods can be 
achieved within one field-campaign. 
5. EXAMPLES OF IMAGE MAPS 
  
Figure 8: Fortification Tower, West-Side 
—377—