2 
INTRODUCTION 
The Universal Automatic Map Compilation 
Equipment (UAMCE) nearing completion at The 
Bunker-Ramo Corporation is intended to produce 
high quality orthophotos and altitude charts from 
a variety of photographic inputs, including con 
vergent frame or panoramic pairs of up to 9 by 18 
inch format. It will be able to set up its own stereo 
models from measurements made when operating 
as a precision stereo comparator. 
The design of the UAMCE is based on the prin 
ciples demonstrated in the very successful Auto 
matic Map Compilation System developed at The 
Bunker-Ramo Corporation.* It includes a number 
of new features intended to enhance its utility in 
a production environment. Like its predecessor, 
the UAMCE is being developed under the sponsor 
ship of the U.S. Army Engineer Geodesy, Intelli 
gence and Mapping Research and Development 
Agency. 
This paper reviews the principles of automatic 
map compilation, describes the implementation 
for the UAMCE, and outlines the anticipated 
operating procedures for comparator measure 
ments and for compilation operations. 
PRINCIPLE OF AUTOMATIC 
MAP COMPILATION 
The principle of automatic map compilation 
from stereo photographs can be understood by 
examining the geometry associated with typical 
aerial photography. An elevation view normal to 
the line of flight of a camera vehicle, with photo 
graphs taken from camera stations Ci and C 2 , is 
presented in Figure 1. A point P(X, Y, Z) in the 
common field of view is shown imaged at p x and 
p 2 on the resulting photographs. 
Figure 1. Development of Height-Error Signal from Stereo Photographs 
Suppose it is desired to determine the altitude 
of point P from measurements on the photographs. 
If a low estimate of the altitude is made (as 
shown in the illustration), the image of P would 
appear to the left of the image of its estimated 
position in Ci and to the right of the image of its 
estimated position in C 2 . If the two photographs 
are synchronously scanned by fine points of light 
moving from left to right along S x and S 2 and 
centered on the estimated positions of the point, 
the signal corresponding to Pi will appear early 
in its scan while that from p 2 will be late in its 
scan. While particular imagery is not identified, 
the differential time between the appearance of 
related imagery provides a measure of error in 
the altitude estimate. 
CORRELATION OF SIGNALS 
The recognition of the similarity between two 
signals, basic to the measurement of the differ 
ential time, is achieved through a correlation 
process which implements the mathematical 
expression 
S(r)= 7 f-i t g(t) h(t — r) dt (1) 
lo Jt — To 
where g(t) and h(t) are the two signals to be 
compared, t is a delay, and S(r) provides the 
desired measure of the similarity of the two sig 
nals over the range of integration; S(t) is a 
measure of the average correlation level over the 
integration time, T 0 . The delay parameter, t, 
allows the signals to be compared with different 
time offsets; the delay that maximizes S(r) pro 
vides the desired measure of the displacement of 
similar or “correctable” elements in the two 
signals. 
Figure 2. Development of Correlation Function for 
Sharply Defined Element 
*S. Bertram. “The Automatic Map Compilation System,” Photogrammetric Engineering (July, 1963). 
S. Bertram. “Application of Hybrid Analog and Digital Techniques in the Automatic Map Compilation System,” Proceedings—Spring Joint Computer 
Conference, 1963.