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9. Offset Measurement
Offset measurement are performed in order to find a point where a target cannot be
installed directly or to find the distance and angle to a point which cannot be sighted.
It is possible to find the distance and angle to a point you wish to measure
（
target Point
）
by installing the target at a location
（
offset point
）
a little distance from the target point
and measuring the distance and angle from the surveying point to the offset point.
The target point could be found in the following four ways.
9.1 Distance Offset Measurement
Sometimes we need to measure a coordinate of a point such as A1 whose position
cannot place a prism. assum that we know the horizontal distance from prism to A1. the
Distance offset measurement can be used.
【
Procedure of distance offset measurement
】
1. Input the known offset distance
A0
A1
T.H.
Horizontal distance
Prism(P)
Center of instrument(CI)
Offset
(dist)
–
Length
Left(-)/Right(+)length
Front(-)/)Len
B.S. Clear Enter