2.3 Summary of the results of the y-parallax tests 
y-parallax measurements were received from participants in the controlled tests of Sub-commissions 
IV:1—IV:3. The test areas and the type of photographs are first briefly described. 
Commission IV:1 
Test area: Monti di Revôira. Large elevation differences. Aerial photography with the following 
cameras: 
Wild R.C. 5a 11. 5/18. Film 
Wild R.C. 7a 10/15 Plates 
Zeiss 2x R.M.K. 21/18 Film 
Commission IV :2 
Test area: The city of Berne, Switzerland. Moderate elevation differences. Camera Wild R.C. 7 
Aviotar 21/18. Film. 
Commission IV :3 
Test area in Canada. Moderate elevation differences. Camera Wild R.C. 5a 15/23. Film. 
2.31 Preliminary tests 
When the results of the y-parallax measurements arrived from the participants some practical 
tests were immediately arranged. In particular results from Sub-commission IV:1 were tested in 
Table 1. 
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
Corrections Standard 
error of unit 
dbz, dos el 
Model Organization dby, de |. | de, 5 weight So9 . | Notes 
mierons e flat |rugged e flat | rugged | flat |rugged 
microns e mierons 
| | 
2899/2900 | Weissmann 1, Zürich 2 |—0.6| —63 | —67 0.4 0.0] —0.2 | 2.2 2.4 | Plates 
» Weissmann 2, M 63 0.6 79 107 3.2 1.8 1.3 5.6 5.4 2 
2900/2901 | Weissmann 1,  " 8 0.4 42 42 3.2 0.0 0.0 | 3.6 3.7 
2 Weissmann 2, » — 108 0.:2| —971 —602 | —1.8 1.7 1.9 3.5 5.7 » 
2412/2413 | Instytut Foto- 
grametrii, Warzawa 60 | —0.3| —28 —6 |—0.2 1.1 1.1]. 5.3 5.1 Film 
» Imatran Voima, 
Helsinki —37 | —0.7 11 0 0.0 —0.6 0.61 3.3 3.8 
>» Lantmäteristyrelsen, 
Stockholm —6 -0.5 3 14 0.2 0.2 0.6 | 4.0 4.2 
2 Vattenfallsstyrelsen, 
Stockholm 23 0.0 46 57 1.8 0.2 0.5 3.5 4.1 
2413/2414 | Vattenfallsstyrelsen 
Stockholm 46 0.2 81 | —51 0.5 0.8 1.4 | 2.8 2.4 
2 Imatran Voima, 
Helsinki 70 0.1 — 3 18 0.0 1.3 1.0 4.6 4.5 2» 
Lantmäteristyrelsen, 
Stockholm 3 0.2 41 35 0.8 0.3 0.3 | 2.8 2.7 ; 
» Vattenfallsstyrelsen, | | | 
Stockholm 85: 00 20 50] 041 17]. 15] 24 ] 25 
  
  
  
  
  
  
  
For $$4—0.01 mm in the model the standard errors of the corrections are: Sapyg = 27 microns, Sqpz, — 12 microns, 
$4,— 0:3, 8, — 0:6 and s,— 0:4. 
The mean square value of the differences of dbz, — 20 microns 
" » " ; "de; =0°3 
^ ç : 
S99 =0.3 microns 
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