International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, Vol XXXV, Part B5. Istanbul 2004 
  
Figure 6a. Surface showed as point clouds in figures b-d 
Figure 6b. Noise content of Riegl scan. 
Figure 6c. Noise content of Mensi scan. 
Figure 6d. Noise content of Optech scan. 
  
  
  
  
Beside numerical results of the alignment, Polyworks is also 
able to display an error map, where the residual 3D distances 
between points of overlapping scans are displayed in different 
colors. Using this tool we noticed that the residual error was 
distributing in different way accordingly to the performed 
alignment: evenly along the overlapping area if scans of 
different sensors were involved, with varying density in the 
case of the same laser scanner (Figures 7-9). Such unexpected 
behavior cannot be well explained: no further comparisons 
could be done using scans from the same sensor, as these parts 
of the Chapel represented the missing areas in the Mensi data 
sets and were surveyed by no more than one laser scanner. 
  
  
Figure 7. Holes in the Mensi data. 
  
Figure 8. Errormap of Optech-Mensi scan alignment. 
  
  
  
   
  
  
  
  
  
  
  
  
  
  
  
   
    
  
     
  
   
  
    
   
  
    
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