| | | | | 
| 
Ve e e 
bis rebos erede aii ad 
fo © 9 o $ 9 9 © bd upp 
UT s ru uy 4 
| , 320m 1 200m | 
| | 
$ -—Q- i G- d -— T. G— i. 
| 
( 4. o d o zh. ex: A a | ) — 1602 
EA tor ir timete ce Jo 
| | | | | 
ree tO me erent my rida -$——-0——--——— 
| | 
| | 
+ — — — — — 601  photostrip 
North 
| 
| map sheet 
| | 1:400 
horizontal 
control point 
Picture No 1. 
1: 400. For economic reasons larger scales can hardly be considered. The 
negative scales mentioned correspond to flying altitudes of 930 metres, 
770 metres, 620 metres and 460 metres. 
Considering these factors, and naturally economic factors too, a deci- 
sion was made in favour of a flying altitude of about 600 metres (scale 
of the negative 1:4 000). 
The photostrips were planned as shown in picture No. 1. The choice 
of an east-west direction of the photostrips provides many advantages, 
209