13 
AUXILIARY EQUIPMENT 
The video signals generated by the photomulti 
pliers at each scanning table are used to drive the 
correlation circuitry. The signals are also used to 
recreate images of the scanned area for exposing 
the orthophoto and to provide a “window” to the 
operation in the form of an electronic stereo 
viewer. The viewer is shown in schematic form in 
Figure 14. It includes two 4-inch, square-faced 
cathode-ray tubes whose images are superposed 
using a half-silvered mirror; separation for stereo 
viewing is achieved through cross-polarized filters 
in front of the two tubes with correspondingly 
polarized glasses worn by the operator. An elec 
tronically generated floating mark (a bright cross 
or dot) provides a stereo reference. 
The UAMCE incorporates a “reference viewer,” 
which is designed to illuminate a point on a print 
corresponding to the area under observation on 
the related diapositive. The viewer, at the upper 
right of the control console, is designed to take 
full-size prints. Switches permit the operator to 
slave the operation to any one of the four tables. 
The reference viewer permits the operator to 
locate the observation area in order that he can 
interpret the image in the stereoviewer. It is also 
used in certain operations not requiring full equip 
ment accuracy (such as initial calibration and 
defining potentially troublesome areas). 
A control keyboard provides operator selection 
of computer programs or operating parameters. 
Keys are provided to select the table to be man 
ually moved, as previously described, and to 
change the sensitivity of the control. Other keys 
cause the computer to go through a defined cali 
bration routine, to go into the comparator or 
compilation operating programs, to take in meas 
ured coordinate data, or to allow manually 
inserted height changes during compilation. 
The tables are manually controlled with a posi 
tion control, which takes the form of a ball whose 
upper surface protrudes above the table top. 
Movement of the ball is communicated to the com 
puter by properly coded signals; the computer 
then commands corresponding motions of the 
tables. This may take the form of combinations 
of x and y motions of a selected table during com 
parator measurements or of Z changes during 
compilation. 
A symbol generator provides video for the gen 
eration of symbols on the orthophoto and altitude 
chart scanners. These are used, under computer 
control, for marking important features, such as 
pass points and map grid coordinates on the 
orthophoto and altitude chart. The symbols are 
generated by a flying-spot scanner, whose light is 
modulated in accordance with a symbol on a mask. 
The symbol is computer-selected, from a field of 
six, by moving the center of the scanning raster. 
The light modulated by the symbol is sensed by a 
photomultiplier and the resulting signal amplified 
for application to the printout tubes. 
OPERATING CHARACTERISTICS 
OF THE UAMCE 
The UAMCE permits an unparalleled operating 
flexibility. This is illustrated in the following 
description of the principal operations performed 
with the equipment. 
Stereocomparator operations can be performed 
simultaneously on four diapositives. Before the 
plates are inserted, a tape is prepared which lists 
the pertinent data for the plates. This includes 
the nominal orientation data, camera station, and 
type of camera (frame or panoramic). In addi