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.