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Fig. 4:
Fig. 5:
10
uring in each region. (See fig.4)
∙ Calculation of altitude difference as
follow:
Altitude difference =
Sum of backsight − Sum of foresight
Altitude of the surveying point =
Altitude of known point
+ Altitude difference
2.2. Measuring horizontal angle
The horizontal-circle-scale is graduated
in minimum value of 1°and numbered
every 10°.
∙ Use the plumb-bob to set the center of
the instrument right above the survey-
ing point.
∙ Aim the telescope at point A and set
the horizontal-circle-scale to 0° by
turning the horizontal circle positing
ring.
∙ Aim the telescope at point B and take
the angle reading. It's the angle of po-
sition between A and B. (See fig. 5)
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