AN INTEGRATED MAPPING SYSTEM 
the minus X direction along the same profile 
at the maximum speed (20 millimeters per 
second). The Z-drive automatically moves 
the measuring mark so that the entire first 
profile is retraced. The operator watches the 
measuring mark to see that it actually re- 
mains in contact with the ground. The profile 
is re-recorded on the temporary tape. 
If the operator is satisfied with the first 
profile, he pushes a “RECORD” button when 
the left end is reached. The profile is retraced 
from left to right once again at maximum 
speed, guided by replay of the temporary 
tape. This time the television pickup tube is 
in the place of the measuring mark, and the 
contour plot and orthophotograph are being 
printed. The first profile is also being recorded 
on the permanent tape and re-recorded on the 
temporary tape. 
When the right end of the first profile is 
reached this time, the measuring mark re- 
places the television pickup tube, and the 
V-drive indexes to the position of the second 
profile. 
This time, as the measuring mark is driven 
to the left along the second profile, it retraces 
the first profile, guided by replay of the tem- 
porary tape. That is, it would retrace the 
first profile if the operator let it. But he uses 
his Z-drive servo control to over-ride the 
memory guidance so that the measuring 
mark actually traces out the second profile. 
That is the essence of memory-aided profiling. 
[t is based on the expectation that successive 
closely spaced profiles differ from each other 
by small amounts, and that an operator can 
readily see the small differences apparent 
during a retrace. The speed of the retrace is at 
all times under the control of the operator. 
The second profile as it is actually traced is 
recorded on the temporary tape. 
[f the operator is satisfied that he was suc- 
cessful in using his override control to trace 
the correct second profile, he pushes his 
“RECORD” button when the left end is 
reached. As before, this causes all recordings 
associated with the second profile to be made 
while the profile is being traced from left to 
right at maximum speed. 
The sequence is followed all through the 
model. Whenever the measuring mark is 
moving to the left, it is retracing the previous 
profile and is subject to override by the opera- 
tor. The permanent tape and the other re- 
cordings are made as the current profile is 
being retraced to the right. 
Whenever the operator wishes to verify or 
correct a profile before recording it, he pushes 
a “NO RECORD” button, which causes the cur- 
rent profile to be retraced, subject to his over- 
ride, as often as necessary. The permanent 
recordings, however, must be made in the 
plus X direction. 
There is considerable flexibility in the fre- 
quency with which orthophotographs and 
permanent recordings are made. It is possible, 
for example, to record on the contour-plot 
every profile, on the orthophotograph every 
other profile (after adjusting the masked 
width of the cathode ray tube) and on the 
permanent tape every fourth profile. 
The purpose of such flexibility is to permit 
tests which will establish optimal precedures 
for the future. The tests will also have to de- 
termine the speed and accuracy attainable 
with the equipment in various types of ter- 
rain. 
A few words remain to be said about the 
properties of the permanent tape profile 
record. It is a more complete record of the 
shape of the earth's surface than a contour 
map can be, and it is in a form which can be 
hand.ed by modern automatic data process- 
ing methods. It is, in fact, the raw material 
for a digital terrain library. A few of the con- 
jectural uses for such a library are: 
a. Recompilation of a map at a different 
contour interval, without additional photo- 
grammetric work. 
b. Revision of contours based on ground- 
control acquired after the original stereo- 
plotting project. 
c. Automatic computation of earthwork in 
the design of highways and other engineering 
structures. 
d. If a convenient method can be devised 
for storing planimetric information in digital 
form in conjunction with the profile record, a 
completely digital map library becomes possi- 
ble. The storage of map information in this 
form would put it all within reach of auto- 
matic processing methods. 
It will be possible for the first time to at- 
tack such problems after the planned tests 
of the Integrated Mapping System have pro- 
duced a body of recorded profiles. 
REFERENCES 
1. Spooner, C. S., Dossi, S. W., and Misulia, M. G., 
"Let's Go Over the Hill," PHOTOGRAMMETRIC 
ENGINEERING, XXIII, 5, December 1957. 
Kosofsky, L. J., “Investigation of an Integrated 
Mapping System,” PHOTOGRAMMETRIC ENGI- 
NEERING, XXIV, 3, June 1958. 
3. Bean, Russell K., “The Development of the 
Orthophotoscope,” PHOTOGRAMMETRIC ENGI- 
NEERING, Vol. XXI, 4 (September 1955). 
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