(119) 
(120) 
(121) 
(122) 
oints 
duces 
(123) 
(124) 
125) 
or 
. sx EEE 
E 
Location of observer or target point respectively. 
Type of application Outside effective atmosphere 
Inside effective atmosphere 
  
Aerial Photogrammetry | Formulas (100), (96) 
(97) &nà (95) 
Formula (122) 
  
Terrestrial Formulas (99), (96), 
Photogrammetry (97) and (93) 
  
  
Formula (115) or (124) 
and (97) or (99) & (94) 
in order of increasing 
precision 
  
Attention must be given to the fact that the computation of z for a specific 
ray is carried out with the coordinates of the center of projection and of a 
specific control point. Thus z, and not (z), is being obtained (Fig. 12). In 
extreme cases of precision terrestrial photogrammetry, it may therefore become . 
necessary to compute a series of refraction corrections according to the follow- 
ing steps: 
Jj 4f 
2. (z)!2 -A* 
5. A" « f(z)! etc. 
The computations are continued until the specific À -value stabilizes. 
Provided (z), + (2), is sufficiently close to 180? (flat earth geometry), 
formulas (115) and (122) can be combined in an expression valid for both a 
ground based or airborne camera. Introducing the notation of this report, the 
center of projection by O and the target point by R, we obtain: 
m - 
A" = A tan (z)o On : À 
a(To- 
69 
Tg) 
(126)