jin. In all 3.2 Powder Tower total facade consists of approximately 32000 object points 
W days so (4 to 8 points per stone). This task could only be handled 
id object For momument preservation purposes detailed plans of by a direct superimposition of graphical data onto the 
the historic Powder Tower of Oldenburg had to be images (Figure 7: Example image of the Oldenburg 
generated. The final results will include a stone-by-stone Powder Tower Figure 8). In the interior a stereoscopic 
registration of the exterior and the interior walls in the — reconstruction of the untextured wall of the dome was 
form of a complete 3-D CAD model. A geodetic net of nessecary. This data was collected on a Zeiss P3 
control points has been established inside and outside ^ analytical plotter running PHOCUS software. The 
the building. Images were taken from all around the measuring results of both systems were transfered to 
object including camera stations from higher positions ^ AutoCAD for further processing. As a result two- 
using a hydraulic lift (Figure 7: Example image of the dimensional drawings and a cylindrical projection of the 
Oldenburg Powder Tower Figure 8). exterior facade have been produced (Figure 9) 
(Tecklenburg 1995). 
3-D Point determination of the exterior walls was 
performed by intersection in the PHIDIAS program. The 
  
FE 33 
Figure 7: Example image of the Oldenburg Powder Tower Figure 8: Superimposition of 3-D CAD data 
  
rocessing ^ = Di dr fant 
  
100 
140 
Mat. 201 
Sent 280 
Stat 270 
Stat. 200 
Stat. 250 
mort. 240 
Stat. 230 
Mat 220 
Stet. 200 
Nat 190 
Stat. 190 
Su 170 
stat 
Stat 160 
Stet. 
ftat. 130 
Stat 120 
Stat. 110 
Stt 100 
L3] 
Stat 80 
Sut. To 
Stat 60 
Sut 50 
Stat. 40 
Sont. 30 
Su 20 
Stat 40 
set 
    
) floor Figure 10: Projection of the principle arch 
239