Kochi, Nobuo 
  
Figure 6 shows the contour lines obtained from GPT and DI-1000 on 9 target points. 
Figure 7 shows the contour lines obtained on 18 target points. 
Figure 8 shows the contour lines obtained from PI-2000 on 170 target points with automatic DTM measurement. 
Figure 9 shows the ortho-image obtained from GPT and DI-1000. 
Figure 10 shows the ortho-image obtained from PI-2000 with automatic DTM measurement. 
Figure 11—14 show the finally obtained ortho-image, cross-section (Figure 11.A~B), TIN image, and contour lines. 
  
Figure 6. 9 Target points Figure 7. 18 Target points Figure 8. 170 Target points 
So, the more the points, the more accurate will be the three-dimensional measurement. 
As it is clear, if you compare the result of figure 9 and figure 10, you will find that the figure 9 evidently lacks the 
aimed points. So, the targets are a bit distorted and location is displaced (Look at the square matrix and the location of 
target). 
Our entire stereo-matching operation used 4335 target points and finished within 2 minutes. 
   
Figure 9. Ortho-image: GPT and DI-1000 Figure 10. Ortho-image :PI-2000(DTM measurement) 
From the above experiment, it is obvious that the stereo-matching, which uses GPT data as its initial values, is much 
more speedy, reliable and accurate than coarse-to-fine-image-correlation. 
And the depth and horizontal accuracy became 1~2cm (rms). As to the accuracy, non-prism TS is = 1 cm. The image 
resolvability is 5mm for horizontal and 13mm for depth dimension. The contour lines (Figure 6~8,14) were drawn for 
each altitude difference of 2cm, which is good. The final target accuracy of our experiment this time was within 5cm. 
So, the result was satisfactory. 
The time spent on the experiment site was about 1 hour. And the time spent for processing from data reading to the final 
ortho-image production was also about 1 hour. However, the ortho-image production itself was only a few seconds. 
Thus, our system will be able to tackle urgent needs. 
  
  
  
  
  
  
A B 
Figure 11. Ortho-image Figure 12. Cross-section (A-B) 
  
438 International Archives of Photogrammetry and Remote Sensing. Vol. XXXIII, Part B5. Amsterdam 2000.