PHOTOGRAMMETRIC ENGINEERING 
Fig. 8. Orthophotograph and line-drop chart by the automatic map compilation System. 
pairs in less than three hours with an ex 
pected accuracy corresponding to a C-factor 
of 5,000. Smaller models and/or reduced 
accuracy would permit lower compilation 
times per model. Included in the console is an 
electronic stereoviewer to permit monitoring 
of the operation during compilation and for 
use during stereocomparator measurement. 
The general area under observation at any 
given time is indicated in a reference viewer 
by a spot of light on the print of one of the 
diapositives. The addition of a number of 
other features makes the equipment also use 
ful as a precision comparator, in which mode 
it will permit virtually simultaneous stereo 
measurements on common areas on four dia 
positives. A standard error measurement of 
less than 4 microns is expected for such 
operations. 
Digital Mapping 
While the UAMCE operates in parallel, 
another system in this class operates in series. 
Moreover, while the UAMCE can be typified 
as a hybrid analog and digital system, the 
second is only digital. “Automatic Mapping 
Using Digital Techniques” by John Sharp up 
dates the work conducted by the Interna 
tional Business Machines Corporation (IBM) 
for GIMRADA. The Digital Automatic Map 
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