X Y X Y 
pixel um pixel um pixel um pixel um 
0.08 0.78 0.11 1.03 0.05 0.50 0.06 0.57 
0.07 0.65 0.08 0.82 0.05 0.51 0.07 0.64 
0.06 0.62 0.07 0.71 0.04 0.43 0.06 0.55 
  
  
  
  
  
  
Table(2) The precision of the observations for the digital photos 
Station 
1.00 
1.25 
0.93 0.08 
um 
4.33 
1.30 
0.83 
um 
1.23 
0:11 0.96 
0.07 0.66 
  
Table(3) The precision of the observations for the scanned photos 
7. DATA EVALUATION 
After determination of the photo coordinates of the inter- 
sections and control points for all images, all three data sets, 
namely hard-copy, digital, and scanned, were evaluated. 
Each project requires two sets of photo coordinates to be 
processed, for three images before and after deformation. 
Due to the unknown systematic errors of both the digital and 
non-metric cameras, a self calibrating bundle adjustment was 
selected for the evaluation ( El-Habrouk et al.,1996). The 
program UNBASC2 ( UNB Analytical Self Calibration) 
(Moniwa, 1977) has several advantage namely: no additional 
control information is needed for the calibration, no 
approximate values for the unknown parameters are required 
except for the principal distance, the calibration is photo- 
variant, and does not require fiducial marks as was the case 
for the digital camera. 
The input data includes photo coordinates, control infor- 
mation, and the iteration sequence to solve sequentially for 
the unknown parameters. The output are the 3D coordinates 
for the unknown points in object space, camera calibration 
parameters as well as accuracy related information. 
150 
8. RESULTS 
Fig.(4) illustrates the deformation behaviour of the roof model, 
as determined by photogrammetry. 
  
Fig.(4) The Deformation of the Roof Model 
International Archives of Photogrammetry and Remote Sensing. Vol. XXXI, Part B5. Vienna 1996 
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