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8. Offset mode
It includes
five functions which are “Offset(Angle)”,
“Offset(Dist1)”,“Offset(Dist2)”,“Offset(Plane)”,“Offset(Column
)”. These functions help for coordinate measurement, and can
get the coordinates of the point which the prism can’t be at.
Before operating these functions, please set ‘STA’, orientation,
instrument height and target height
.
8.1 Offset (Angle)
This mode is specifically useful when setting up prism
difficultly, e.g. in the center of a tree. Set up the prism at the
point ‘P’ which is the same horizontal distance away from the
instrument .The diagram for angle offset is as followed.
Instrument center
Station
A0
A1
Prism P
HD(f)
HD(r)
HD(r)=HD(f)
HD(r): the horizontal distance between
prism to instrument center
HD(f):the horizontal distance between
prism to instrument center
When measuring the coordinate of the earth point‘A1’
which is the projection of ‘AO’, set up the height of instrument
and the height of target.
When measuring the coordinate of ‘AO’, set up the height
of instrument only (and the height of target should be set to 0).
In the menu of “Offset”, select “1. Offset (Angle)” to enter
the interface of “Offset (angle)-Prism”:
