-9- 
( 3c).. determination of the first derivatives of these six 
elements (i.e. airplane's speeds ax/dt, aY/at; rate 
  
  
of climb or descent az/àt; rotational changes in 
attitude doe /àt, ag /at; and heading and drift 
changes dy/dt),and continuously recording these 
  
  
changes digitally. 
In case of aerial data scanning, this record is needed 
not only to "position" the data which are scanning- 
recorded, but also to "rectify" these data into an 
earth coordinate system. 
(9 
  
  
  
  
mac € 
Zz Er 
SW I... 
ETELL pathos. ... 0 ze 
vr? a i —" 
Dy 
|. & 
(0 
  
    
  
  
ELEMENTS OF 
OUTER ORIENTATION 
and DER\VATIVES (sPEGDS ) 
IN FLIGHT 
Figure 5