International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, Vol XXXV, Part B5. Istanbul 2004 
  
the kiln can be observed in each picture .The generic scheme of 
photography stations is shown in figure 3. 
S Photography scheme 
  
  
Figure 3. Scheme of five stations for photography 
With the focal length of 7-70mm at the distance of 10-20m the 
scale of photography differs between 1/1400 for three pictures 
and 1/140 and 1/280 for the others according to the focal 
lengths computed and shown in the tables 2 and 3. 
4.2.5 Targets’ designing : Shape of the targets on the kiln is 
shown in figure 4: 
100mm 
  
  
Figure 4. Shape of the targets 
We chose the circular form because of its homogeneity and also 
independency of measurements in directions and the cross in 
the middle of the circle helps us to target it easily with 
theodolites, and accordingly calculate the coordinates of the 
centre of the circle, with surveying methods. The size of the 
targets depends on the resolution and due to the high resolution 
of the pictures, perfect specifications of the camera that is 
shown in table 1 and a test photography that is performed 
before the project in the same distances, the radius of the target 
was selected: 50 mm. 
Because of the high temperature and the rough shell in the place 
of targets, we decided to draw the targets by colour through a 
designed shablon. 
According to the resolution of the camera, the size of each pixel 
on the images, equals to 0.14mm, so with considering the scale 
of photographs (1/150, 1/300, 1/1500) and zooming availability 
in computer this size of targets was suitable. A sample image is 
shown in figure 5. 
  
Figure 5. A sample image 
4.2.6 Designing control points places : In bundle adjustments 
of well-designed photogrammetric networks, the number of 
object points has surprisingly great impact on the mean standard 
error (Fraser, 1984). Due to this practical dependency of object 
point precision and the number of target points, network that is 
planned to include points can be examined and optimized at 
  
designing stage by considering 17 well-distributed targets. This 
leads to considerable savings in the computations. 
Whereas the accuracy attained in a standard bundle adjustment 
Is significantly influenced by the number of target points, the 
precision yielded in a self-calibration adjustment is 
considerably affected by both the density and the distribution of 
the object points. 
For designing points and satisfying project goals, it was 
necessary to select stable points while roller is rotating, to be 
assured of their fixed position during kiln movements. So, it 
was necessary to have fixed control points on the kiln. It is 
better to have an absolute monitoring system. For having an 
absolute displacement monitoring system, two base points are 
established in the area with high stability by steel bolts which 
have great resistancy against environmental conditions. 
Distance and direction observations between these two base 
points are measured by the most accurate instruments available. 
Distances are measured by MES000 mecometer with 
(0.2mm+0.2ppm) accuracy and directions are measured by 
T2002 with (0.5") accuracy. For considering temperature and 
pressure corrections on the distances, temperature 
measurements with 1?c accuracy and pressure measurements 
with 3 mbar accuracy were performed. 
After establishment two base points, direction observations 
from these two base point to 17 control point on the object were 
performed in 4 couples and the ground coordinates of the 
control points were calculated by intersection method . Position 
of the two base points and control points is shown in figure 6. 
  
  
  
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Figure 6. Position of the two base point and control points 
Vertical and horizontal angles from two base points to 17 
control points were observed. According to the 0.5" accuracy of 
the T2002 instrument the expected accuracy for control points 
coordinates was 0.5 mm.The ground coordinates of the control 
points were calculated by intersection method. After writing a 
program for calculating the ground coordinates of control points 
on the object, the results retrieved. 
4.2.7 Location and number of unknown targets : Since 
main goal of this project is to present capability of close-range 
photogrammetry for monitoring and measuring point 
movements in a structure, a suitable layout of points on the 
structure was selected. 
One of the capabilities of Close-range photogrammetry is to 
determine any movement of points on the structure. Therefore, 
four points with a descent density were marked on the kiln. All 
these points were involved in computation of camera 
parameters and the amount of displacements and directions of 
displacements were determined. 
Because of the quality of the object (a solid mass), mean value 
of computed displacements for four points on the object can be 
considered as displacement of the roller. 
  
  
    
   
  
  
  
  
  
  
  
  
  
  
  
  
  
  
   
   
    
   
     
  
  
  
   
   
  
   
  
  
  
  
  
  
  
  
   
    
    
    
   
  
    
    
   
  
     
   
    
  
  
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