14 
tion, rough positions of desirable pass points are 
entered. A program sheet that defines the task of 
the operator is also prepared, listing the measure 
ments to be performed. 
With the tape entered into the computer, the 
diapositives inserted, and an appropriately marked 
print on the reference viewer, the operator presses 
the appropriate control key to start the operation. 
The computer then commands all tables having 
diapositives showing the first pass point to move 
to the designated coordinates. It also adjusts the 
shape of the scans at the diapositives in accord 
ance with the nominal orientation data, in order 
to present a virtually undistorted vertical view at 
the stereoviewer (even with panoramic photos). 
Following the instructions on the program sheet, 
the operator switches the stereoviewer to a 
selected diapositive and proceeds to center the 
pass point on the crosshair, using the position 
control. One image of the stereoviewer is then 
switched to a second diapositive and the position 
control used to center the pass point in the field 
of view. Two alternatives are available for the 
final centering: 
(1) The operator may take advantage of the 
expanded picture, 90-degree rotation, and 
interchange of left and right images to 
manually center the second image to coin 
cide with the first. 
(2) The operator, through the keyboard con 
trol, can command the correlation circuitry 
to make the final centering adjustment. 
The second alternative is obviously the more 
desirable. However it is not always possible; for 
example, if the area in the field of view has an 
appreciable variation in altitude, it will be neces 
sary for the operator to adjust the coincidence 
for the desired point. The stereoviewer is then 
used with the third and fourth diapositives (or as 
many as include the pass point) and the process 
repeated. When the operator decides that the 
centering on all diapositives is satisfactory, he 
depresses the “store data” button, causing the 
computer to place the measured coordinates in 
an appropriate store. The operation is then 
repeated for the next pass point. 
When the measurements have been completed, 
the data (together with geodetic control) will be 
used to calculate the orientation data required 
for compilation. 
Compilation operations require the orientation 
data (including lens and film distortion character 
istics) and measurement of the machine coordi 
nates of two reference points (e.g., two fiducial 
points) to establish the interior orientation; of 
course, the measurement is not required if the 
diapositives have just been measured in the com 
parator mode. The inputs also include the coordi 
nates of the corners of the area to be compiled, 
the desired scale for the output, and the coordi 
nates of points to be marked. The geographic 
position corresponding to the center of the output 
film sheets is also defined. 
Using a print of one of the diapositives on the 
reference viewer, the operator next moves the 
point of light around areas he judges to be poten 
tially troublesome. After an area has been out 
lined, the operator presses a button to select 
the program to be used when the area is being 
compiled. The program includes the following 
instructions : 
(1) Hold altitude (as over a water area) 
(2) Take smaller profiling increments 
(3) Move across the area, then stop for the 
operator to determine the altitude 
(4) Proceed slowly under operator control of 
altitude. 
When the instructions have been completed, the 
film sheets are inserted into the output tables (if 
the compilation is to be one of a mosaic set, the 
film might already be in the tables). The control 
and map grid points are then suitably marked 
under computer command and, finally, the com 
puter moves the tables to the compilation start 
position. 
The operator then uses the position control to 
find the altitude of the start point. With this 
accomplished he can depress the “start” button 
to begin the compilation mode, after which his 
job is to monitor the operation through the stereo 
viewer until manual action is required. Operator 
action will be required only in very difficult ter 
rains; the operator can mark these for attention 
before the compilation. 
FUTURE OF AUTOMATIC 
MAP COMPILATION 
The success of the Automatic Map Compilation 
System demonstrated the feasibility of such equip 
ment and ensured the success of the UAMCE. The 
new equipment has many features, not present in 
the original, that make it useful as a precision 
comparator and enhance its potential as a com 
pilation instrument. However, it cannot be claimed 
that the UAMCE is the ultimate instrument. Until 
the time that automatic equipment will be able 
to produce fully annotated, properly colored maps 
without the attention of an operator, improve 
ments will be sought. It is useful to examine the 
potential in various areas of the operation. 
The UAMCE allows 10 milliseconds for each 
altitude measurement — about a third of that 
required by the earlier system. The improvement 
is a result of (1) the higher intensity flying-spot 
scanners, which result in a significant improve 
ment in the signal-to-noise ratio and (2) a more 
effective scanning pattern that provides a good 
averaging over the area in a few scan lines, per 
mitting higher gain in the height-error loop before