AUTOMATIC PHOTOGRAMMETRIC INSTRUMENTS 
Fig. 7. Automatic map compilation system Figures A & B 
The speed advantage in the UAMCE is 
gained by plane parallel scanning at one-to- 
one scale. The operation of the equipment is 
essentially parallel since it produces a line- 
drop chart and an orthophotograph as the 
area is scanned. The output ground coordi 
nates are used as reference so that the scan is 
along a line which is straight on the map 
plane. As the computer centers the syn 
chronous scans on small areas of the stereopair 
corresponding to a given geographic position 
at an estimated altitude, electronic cor 
relators and auxiliary circuitry determine the 
error in height and signal the computer. The 
computer updates its estimate and makes an 
estimate for the next point in the profiling 
sequence. This height is the basis for the alti 
tude chart and the video from one of the 
photographs produces the orthophotograph. 
The UAMCE will make one hundred 
(100) altitude measurements per second thus 
permitting detailed coverage of 9-X 18-inch 
100 per cent overlap, 30° convergent stereo-