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2. Video theodolite system 
In order to measure the rotation parameters in real 
time, a CCD camera was mounted on top of a theodolite. 
wand x were defined as the vertical and horizontal 
angles respectively, ó assumed to be 0 degrees as the 
theodolite is levelled. The authors have concentrated on 
developing the video theodolite system consisting of a 
CCD camera, a theodolite and a video recorder where 
the camera rotation parameters can be determined in 
real time while recording a moving object. The current 
values of the rotation parameters were then 
continuously superimposed on the image frames and 
thus recorded as a part of the image data. 
Table 1 shows the composition of the video theodolite 
System and Figure 3 shows the configuration of this 
system. In this video theodolite system, since the CCD 
camera was mounted on a telescope which was 
reversed, resulting in the zenith angle being 
superimposed instead of the vertical angle. 
3.Experiment 
111 
Table 1 Video theodolite system 
  
Theodolite DT20ES (Sokkia, accuracy +20") 
CCD Camera XC-75 (Sony, 768H x 494V, 14.318 Mhz) 
Lens VCL-16YM (Sony, f=16mm) 
A/D Convertor FRM-512 (Photron, 12.28 Mhz) 
Video Recorder HR-SC1000 (Victor) 
  
  
  
Monitor PVM-1454Q (Sony) 
PC PC-9801BX (NEC) 
(= 
T image 
CCD Camera PC 
  
  
  
  
  
TV Monitor 
   
Theodolite 
Figure 3 Video theodolite system configuration 
In order to confirm the relationship between the rotation parameters (v,  ) and the reading angles (zenith, horizontal) 
of a theodolite, following experiment was performed by using a test field (Fig.4). The first image was taken when the 
video theodolite which was nearly parallel with the X,Y plane of the test field. The left-hand number which was 
superimposed in the upper and left corner of the first image shows the zenith angle (V,=37°1' 50") and the right-hand 
number is the horizontal angle (H,=0°0'00"). The second image was taken by turning the theodolite 26°18'40" 
counterclockwise and 3°3'10" above horizon, giving V,=40°5'00" and H,=26°18'40". 
Table 2 shows the calibration results and the accuracy of the orientation parameters for both images with 9 control 
points. 
   
  
  
No.2 image 
image 
  
  
Figure 4 Test field 
IAPRS, Vol. 30, Part 5W1, ISPRS Intercommission Workshop "From Pixels to Sequences", Zurich, March 22-24 1995