178 
Table 3. Comparison of exterior orientation parameters. 
(Coordinates in feet.) 
Parameter Monocomparator Auto Recognition 
Result Result 
Photo 73 
Photo 74 
Photo 73 
Photo 
74 
Omega 
-0 °14'48" 
-0 °19'32" 
-0 °13'12" 
-0°20 ' 
43' 
Phi 
-0 °18'58" 
-0 °12'00" 
-0°17 , 49" 
-0°13 ' 
27' 
Kappa 
1 ° 01'2 8 " 
1°20'04" 
1 ° 01'2 7 " 
1°19 ' 
53' 
X 
55205.4 
57011.7 
55206.9 
57010 
.9 
Y 
26009.3 
26102.5 
26008.8 
26103 
.8 
Z 
3865.1 
3843.1 
3865.5 
3843 
.9 
CONCLUSIONS 
Coordinates of points on digital images can indeed be re 
fined to significantly less than a whole pixel. This allows 
scanning at larger pixel sizes while retaining desired 
accuracy. The massive quantities of digital data in the 
photography can thus be reduced, resulting in a cost savings 
for data storage and computation. 
Scanner distortion is still a definite problem which cannot 
be neglected. Use of a reseau camera or a more stable 
scanner should alleviate this problem. 
Automatically generated DTMs are feasible and will likely 
be used in the future to reduce cost and increase speed of 
map compilation. The research described is just a small 
step toward developing an automated mapping system. Further 
research into automated mapping should be undertaken to 
improve accuracies and reduce costs. The results achieved 
in this investigation are encouraging. 
REFERENCES 
Keating, T.J., P.R. Wolf, and F.L. Scarpace, "An Improved 
Method of Digital Image Correlation from Scanned Densito- 
metric Data," Photogrammetric Engineering and Remote Sensing, 
v. 41, n. 8, August, 1975. 
Keating, T.J., Analytical Photogrammetry from Digitized 
Image Densities'^ Ph.D. Thesis , University of Wisconsin, L975. 
Masry, S.E., "Digital Correlation Principles," Photogram 
metric Engineering, v 40, n 3, March, 1974. 
Moik, J.G., Digital Processing of Remotely Sensed Images, 
NASA Scientific and Technical Branch, 1980. 
Wolf, P.R., and T.J. Keating, "Aerotriangulation Utilizing 
Digital Correlation of Image Densities," Presented Paper at 
the Aerial Triangulation Symposium, Department of Surveying, 
University of Queensland, Australia, October, 1979. 
Wolf, P.R., and J.C. Storey, "Automatic DTM Generation from 
Digitized Image Densities," Presented Paper, ACSM-ASP 
Spring Convention, Denver, Colorado, March, 1982.