PHOTOGRAMMETRIC ENGINEERING 
     
  
  
  
  
   
  
  
   
   
   
  
   
  
  
  
  
  
  
  
  
  
   
  
  
  
   
   
   
  
  
    
yz" bz" of the 
22 Cnm (5b) 
The difference x'—x' of the image coordinates is thus denoted p and js 
called the x — or horizontal parallax. Below only the word parallax will be used, 
One also sees that two determinations of the z-coordinate are possible, and 
that any disagreement indicates errors of measurements or computations. Of 
course, attention has to be paid to the relative elevation of the stations. 
  
Ti 
Fo 
Fr 
1. 
db, dc, 
2, 
tional 
ureme 
camer: 
Fo 
camer: 
grid fr 
tions 1 
venien 
observ 
of the 
of the 
Th 
POMMES m . as p=: 
| Fıc. 4.—Wild phototheodolite. Fıc. 5.—Wild stereocamera, b=120 cm. inner ¢ 
| and x^ 
| The given formulas are called the fundamental formulas of stereo-photo- betwee 
| grammetry. errors | 
| For other cases, for instance the vergent, parallel averted, etc. cases, similar control 
formulas can easily be derived. See for instance 5. connec 
| outer ¢ 
| 1. THEORY OF ERRORS FOR THE NORMAL CASE located 
  
| | II THE FUNDAMENTAL ERROR EXPRESSIONS. i E 
(| : ; : . or the 
The accuracy of the coordinate determination according to the formulas coordi 
(3) — (5) is of course an important question. Small errors in the determination