usted that 
tal to zero. 
4, separate 
The discrepancies in X, Y and Z in the usable test points are graphically shown 
in diagrams included in another chapter of the final report of the Group of Study. 
3 in X, Y 
mentioned 
rip adjust- 
4.3. Analysis of Results. — It is our opinion that the above given results fell 
short of the accuracy hoped for, and that they do not represent the inherent accuracy 
of the methods used. Among the reasons for such disappointing results are the fol 
lowing: 
1. Film Diapositives: This was associated with irregular film shrinkage and 
caused weaknesses in the block, especially in strips 3 and 4. 
2. Identification Difficulties: Out of 295 test points, only 229 were identifiable 
with some degree of certainty. More than half of these points left much 
2 Gr 20 E 
18 
j- 50 G» 80 N 
1 
to be desired in either the sketches or the selection of the point. 
3. Lack of Experience: The triangulation team was composed mainly of 
graduate students with no extensive experience in operating the stereo- 
-0.* j 
- 2.1 
- 89 1 
1 
*35 | 
plotters. 
-81 
1 
*0.0 
-0.4 
i -4.2 j 
5 DURATION OF THE DIFFERENT STAGES OF THE WORK 
-3-5 
+1.4 
*2.1 I 
*2 S 
-9-5 
5.1. Preparation. — Total 250 man-hours (selection and numbering of pass and 
tie points: 150 man-hour; preparing sketches for pass points: 80 man-hours; preparation 
1 
-2.1 1 
+4.3 
♦ 1 .5 
of different tables: 20 man-hours). 
*13 
-1.8 
+ 1.3 
. 50 Gr N 
2 6* 20 E 
5.2. Triangulation on Wild Al (11 strips—177 models). — Total 400 man-hours 
(17 days, 4 men working in 6 hours shifts around the clock. An average of 30 minutes 
per model for relative orientation; an average of 65 minutes per model for conjunction 
of the model to its predecessor; an average of 40 minutes per model to identify the 
pass and control points and write down the coordinates—the electric read-out system 
value 
was out of order). 
e identifi- 
following 
■ed blund- 
dng mean 
5.3. Adjustment. — Total 120 man-hours (20 man-hours for preparation of the 
data for the electronic computer; 2 hours time on IBM 650 to process the first phase 
of adjustment according to the Cross-Bases Method; 78 man-hours to graphically 
undertake the second phase of adjustment according to Zarzycki’s Interpolation 
Method; 20 man-hours for the final block adjustment). 
i in strips 
Note: The second phase of adjustment has been incorporated lately in the IBM 
7090 program for adjustment. An estimated 20 man-hours for preparing decks etc., 
and about 5 or 6 minutes on IBM 7090 would be necessary to undertake the adjust 
ment of the 11 strips. 
6 — GENERAL REMARKS 
1.2. 
The participation of the University of Illinois in the activities of the Study 
Group for Experimental Research on Blocks of Strips was made possible by a grant 
from the National Science Foundatoin (NSF G 19749). Our thanks to NSF for the 
financial support. 
79