432 
n — 1 degrees of freedom, where n is the number of photographs in 
the strip have been used for the practical and theoretic values. The 
following ratios have been found: 
The strip 6010a 0 1.88 Q /. 1.46 
6010b 0 1.43 Q 1.08 
6011 0 1.22 Q 1.44 
The table values for F 2 .5 are 2.31, 2.68 and 4.03 in the respective 
strips. Consequently it may be assumed that practical and theoretic 
values are similar, proving that two determinations of the inclination 
angles from differeni image halves do not give significant correlations 
provided that the assumptions for the theoretic derivations with respect 
to the interior orientation of the main camera have been right. 
7. The precision of the horizon camera values. 
2—3 reference pictures have been used in measuring the horizon 
pictures. Thus there are many determinations of the inclination angles. 
The precision of the inclination angles has been computed by means 
of these values and the following result has been obtained: 
s 
S M 
s 
S M 
Strip 6010a 
0 
2.1 I e 
1.22 c 
Q 
2.07 c 
1.20 e 
6010b 
0 
1.39 c 
0.98 c 
Q 
1.26 e 
0.89 e 
6011 
0 
1.26 c 
0.89 c 
Q 
2.87 e 
2.03 e 
Root mean 
square value 
0 
1.74 c 
o 
GO 
rs 
Q 
2.03 e 
1.32 e 
where s — the standard deviation of one measurement 
and s M = „ ,, „ „ the arithmetic mean 
According to the formula (2) it is possible to calculate the precision 
of the image coordinates in the horizon pictures backwards. After 
inserting the standard deviations into the quantities /3, R and h the 
following result is obtained: 
Si = —75= V /s 7 + s 3 2 (25) 
f V 6 > 
where Sj_= the standard deviation of one measurement 
$2 }> >> >> >> >> >> 
s 3 >> ” >> >> >> >> 
P = 6366.2 c 
(0.01 g ) in p 
(mm) in R 
(mm) in h