Martin Smith 
  
Curve 1 (model data) = 1021 points (average 8.9m between scaled points) 
Curve 2 (ground data) = 3535 points (average 2.7m between points) 
Number of matched points = 352 points 
Figure 4 shows the distribution of points that have been matched. 
RMSE plan = 0.54m 
RMSE height = 0.52m 
  
  
  
  
40 
30 
20 
|B 10 
| o 
FE 
0 
-10 
20.0 
1000 :: 
— 4000 
ue = 0 
000 21000 
Northings 1000 Eastings 
Figure 4. Perspective view showing final matched matched points between model and GPS curves 
(GPS curve = - - -; model curve = +++; all coordinates in metres) 
  
Using traditional ground coordinated points this model has a particularly good absolute orientation with RMSE X = 
0.15m, RMSE Y = 0.14m and RMSE Z = 0.13m. More typical for 1:10 000 scale photography you might expect 
coordinate values in the region of 0.25 — 0.35m which is still a little better than achieved (= 0.5m). So. although the 
curve matching is not good enough for perhaps traditional topographic mapping it would be suitable for many other less 
demanding applications such as geological and environmental purposes. 
5.1.2 Silsoe, Buckinghamshire photography results. The photography is 1:10 000 scale of a relatively flat area with 
some gentle slopes at the edges of the model. The linear features (roads and paths) are fairly straight and approximately 
perpendicular or parallel to each other see figure 5. Curves were recorded on foot by kinematic GPS and on the SD2000 
— Co Uu —- 00 | 
< Un 
  
for model coordinates. 
  
  
  
x 10° 
2.364 
2.362 [^ 
2.36 -+ + qum 
2.358 
” 2356} 
354r 
2352 
235 
2.348 
5.08 5.085 5.09 5.095 5.1 
A X 10° 
Figure 5. Plan view of the model points used in final matching iteration 
(all coordinates in metres) 
  
  
  
  
854 International Archives of Photogrammetry and Remote Sensing. Vol. XXXIII, Part B3. Amsterdam 2000. 
  
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