Graphical output of the system is provided by the coordinatograph. 
In the standard AP-Z system, coordinatograph motions are coupled 
directly to the handwheels and footwheel of the viewing unit by means 
of synchro links. In the automated system, the coordinatograph synchros 
are replaced by servos. These servos are controlled by the computer so 
as to permit operation of the system without actual rotation of the 
handwheels or footwheel. This modified configuration is the one shown 
in Figure Z. 
IMAGE CORRELATION SYSTEM 
The principal components of the image correlation system and 
their relationship to the AP-Z are shown in Figure 3. All other com 
ponents and relationships of the basic AP-Z system remain as indi 
cated in Figure Z. 
Figure 3 - Principal elements of the image correlation system