ET 
  
- dk! , - (X, , Y. 2.9, vector of unknown object 
coordinates of the points i 
T 
"dt ; (X,c,? Yee? Z,c P: oy; , $,; D vector of 
unknown exterior orientation paramters of the image J. 
All simulations completed so far, are based on greatly 
simplified assumptions: 
- no drift or datum parameters for the observed exterior 
orientation data 
- no correlation between the observed exterior 
orientation data 
- no systematic image errors 
- no correlation between the observed control point 
coordinates 
- random error distribution for all observations 
- interior orientation assumed as fixed and faultless 
- standard deviation of observed image coordinates: 
Ope, ei dom S215 um 
- standard deviation of observed control point 
coordinates: Oy n= Oy 07 * + 0.0 m 
- flat terrain, ideal overlap and regular pattern of 
points 
- constant flying height, strictly vertical photographs. 
Fixed flight parameters: 
- flat aera with z - 0,0 m for ail terrain points 
- image scale m, = 1 : 60 000 
- focal length ce = 150,0 mm 
- forward overlap p = 60 % 
- side overlap q = 20 % 
- 9 points per image in standard location 
2.2 Variation of project parameters 
Variable project parameters are: block size, ground 
control, different groups of observed exterior orient- 
ation elements with different accuracy assumptions. The 
various cases are coded as follows: 
- block size 
* Bl 10 x 41 photographs (approx. 100 x 200 km?) 
* B2 5 x 21 photographs (approx. 50 x 100 km?) 
- ground control 
* CO no ground control 
* C1 4 XYZ control points 
* C2 2 'chaiîins of vertical control + 2 x 2 horizontal 
control 
* C3 3 chains of vertical control + 5 x 2 horizontal 
control 
* C5 5 chains of vertical control + 5 x 2 horizontal 
control 
- 27% -