, Y and Z 
mes evi 
solve the 
) considera 
sx, Y. 
on of Z, 
©, the un 
| each pair 
,, it is ne 
i8 radii) in 
least squa 
more than 
| new unknoms 
equation. 
| rests in 
‚ppropriate 
r to define 
section of 
tion is used, 
jJutation of 
the relative 
^ the points 
based on e 
tion of two 
‚ts obtained 
7e orientation 
soordinates 
ously with 
and third 
  
   
(ip) (5) (p) (p)y 
  
  
224m. e US à A 5) 
Sr) " "x(2) 
and 
NES (p) 
x = x) + ba) iz + 203) or 
an v) (n). ; 5^) 
Rex. uou 25 
From the second and fourth 
(p) CP) (np) _ „(p) 
p.28 10) 740057 250 
(1) t - | 6) 
Y(4) Y(2) 
m D) (p) 
fe GU ate) (2 2015) or 
6!) 
= +p) (p) 
rRNA nU 00) 
In order to define the intersection, the two values of Z, (5) and 
( 6) , must be equal. From this we deduce that the condition of intersec 
tion is = | 
(x(®) _ x(P)) (2) xu) (QU) 2 400, , 
(2) (1) ixi) - *x(2) (2) (1) 
7) 
t ab) ; 267) x(2) C) 7 O0) 50). 0 
Sx CO) T *x(2) 
It oan be easily verified that if approximate values for the coordi 
nates and the tangents of direction are introduced, a value is obtained = 
which is none other than the parallax V between the two homologous direc 
tions. A 
We can thus designate equation 7) as the "equation to the parallax." 
This differs from the normal case of photograms (taken without the interven 
tion of noticeable movements during photographing) by reason of the fact 
that in the coordinates of the photographing points and in the coordinates 
of direction there are present those parameters which refer to the movement