38 
5 TIME EXPENDITURE, IN HOURS (COMPUTER TIME 
BOLD TYPE) 
Zeiss Jena 1818 Nistri TA3 
Wild A7 
a) Preparations for the strip triangulations: 
Selecting points for relative orientation and tie points, 
marking points 
87 
80 
80 
Measuring and recording on stereocomparator 
216 
280 
Computing principal points, punching photograph coord 
inates and checking 
86 
65 
b) Strip triangulations: 
Triangulating the strips 
9.5 
5.1 
170 
Checking strip coordinates, correcting errors 
51 
20 
Averaging coordinates of points, measured in more than 
one model, punching strip coordinates, checking .... 
28 
20 
25 
c) Preparations for the block adjustments: 
Preparing for approximate positioning and leveling, 
checking results 
24 
18 
30 
Approximate positioning and leveling 
0.5 
0.6 
1.0 
Selecting tie points to be used in the adjustment, sorting 
cards, preparing control cards 
28 
30 
30 
d) Block adjustments: 
Second-degree transformation of the block as a unit . . 
0.45 
0.6 
0.6 
Checking on identification errors in the 18 ground control 
points 
35 
50 
Second-degree adjustments on corner points 
1.9 
2.1 
3.75 
on western and eastern points 
1.9 
2.45 
on perimeter points 
1.9 
1.75 
1.8 
Third-degree transformation of the block as a unit 
0.85 
0.95 
Averaging of coordinates of ground control points and 
(for the Zeiss Jena strips) hand-computing of discre 
pancies on tie points or averages, per adjustment . . . 
6 
3 
3 
Totals for the strip triangulations 
468 
465 
275 
9 5 
5.1 
— 
Totals for a block adjustment 
58 
86 
113 
(average) 
2.8 
3.1 
4.2 
These figures require the following comments. 
1. Points for relative orientation and tie points were selected and marked at 
intervals during the measuring periods. For the Zeiss Jena measurements, this was 
done by the operator who made the measurements. For the Nistri TA3 and the Wild A7 
measurements, it was done by the two operators together. In each case, a careful 
estimate of the required time was made and subtracted from the measuring period.