93 
In other words, the most favourable number of pairs of photographs 
is about 5 for the stereo-radial triangulation. From (358) we further 
find for c — 150 mm 
m, = 0,0175 5,8 (363) 
where s, is to be expressed in millimeters. For s, — 0,01 mm we find 
m, = 0,00017 § (364) 
For S — 20 km the flying altitude would become about 7 000 meters 
and the radial standard error in the middle of the strip about 3,4 meters 
for s, — 0,01 mm and c — 150 mm. 
5.2. Independent model triangulation 
n 
For p — 9 ve find from (352) 
h ARE 
m, = 8 157, Yn (65 n? + 832) (365) 
Using the same procedure as above we find a minimum of m, for 
h — 04TS (366) 
or 
S = 21h 
Further we find 
n =" 4 (367) 
and for c — 150 mm 
m, — 0,0222 5, (368) 
For s, — 0,01 mm we find 
m, — 0,00022 5 (369) 
For S — 20 km we find 
h — 9400 meters 
and 
m, = 4,4 meters