Practical Example and Tests 
  
The program GEBAT has been applied to a practical project in an indus- 
trial environment (see Figure 1). It consisted of a dense network that con- 
tained some 70 points in an area of about 15 by 15 m2. Due to the nature of 
the network and the tight time schedule, that required the adjustment of the 
network in a relatively short period of time, it was decided to use photo- 
grammetry rather than conventional surveying. The use of surveying would 
have required thousands of observations and, although the area is small, 
would have required a long time and thus been rather costly. However, it 
was easy to level the network with 0.5 mm standard deviation using precision 
leveling equipment. Furthermore, some 150 space distances had been taped 
arbitrarily, again with 0.5 mm standard deviation. The required accuracy of 
the adjusted coordinates was 1 to 2 mm. 
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Figure 1: Industrial Network 
This network was adjusted with the basic GEBAT system using the avail- 
able information and yielded an absolute coordinate error of 0.4 mm,and 1.6 
mm for the semi major axis of the 957 confidence ellipsoid. 
In order to test GEBAT-V, 4 control points were held in this network 
for a series of adjustments with different combinations of distances. 
The results given in Table 1 were obtained using 32check points. 
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