b. Controlling automatic searching procedures when 
loss of correlation occurs 
c. Recording coordinates of plotting gaps for subsequent 
manual fill-in 
d. Selecting the preferred video signal for orthophoto 
compilation. 
The input-output interfaces associated with the incremental 
section are also expanded in the AS-11B/C system to provide real-time 
communication with the image correlation and orthophotoscope equip- 
ment. 
(3) Coordinatograph - The coordinatograph has an "H" 
type of axis configuration to position the plotting head. The 
head is positioned directly in one direction, designed the Y 
direction, by a servo drive. The entire Y mechanism, including 
the plotting head, is positioned in the X direction by two servo 
drive systems, one at each side of the table, The plotting area 
is slightly greater than 1 meter square. 
  
(4) Correlator Cabinet - This cabinet contains the 
electronic correlation circuitry and the electrical components 
which control the coordinatograph servos. An oscilloscope on 
this cabinet allows visual observation of the image being scanned. 
  
(5) Orthophoto Controller - This cabinet contains the 
scan-generation and time sharing circuitry which is special to 
the orthophotoscope operation and the form-line generator. 
  
The controls for setting print pattern size, scale factor 
and contour chart line width are on the control panel of this 
cabinet, 
(6) Orthophoto Printer - The printer is a modified AS-11B 
viewing unit, containing similar CRT assemblies, CRT optics, and 
precision servo-driven photocarriages. The upper housing of the 
printer provides facilities for loading and removing recording 
film under normal room lighting. The recording films are held 
upon the horizontal plane of the photocarriages by a vacuum 
system. The orthophoto is printed on one carriage and the 
form-line contour chart is printed simultaneously on the other. 
A shelf to contain two film magazines is also inside the printer. 
  
The control panel on the printer contains, e.g., controls 
for setting Gain, Intensity, and Gamma. Controls for the printing 
of either a negative or positive product and the carriage vacuum 
are also there. 
(7) Magnetic Tape Recorder - This is an Incremental 
Magnetic Tape Recorder which prepares IBM compatible tape at random 
or non-standard rates. The data is recorded in seven tracks on 
1/2 inch tape at a density of 200 characters per inch. The unit 
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