Spectra Precision FAST Survey Reference Manual - Manual (Page 141)

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2-reading option), and a new point ID will be stored. Within Offset, whenever you do a fresh, new Read, you will
substitute the new reading for the one previously stored in memory. If you have no previous measurement, a new Read
is required within O for Offset. So in summary, you can offset something you've already measured, or you can take a
fresh measurement (typical method), using O for Offset.
The total station Offset command must be selected each time it is used. It has three options:
 Distance/Angle
(sometimes referred to as “Shoot a Big Tree”): The Distance/Angle method requires two
measurements. The first measurement is the distance, followed by the prompt to read the angle. Note that the
dialog, shown in the next figure, prompts you to Read Distance first.
In the case of shooting a large tree, where the goal is to shoot the center of the tree, you would take a shot to the
middle-side of the tree, equivalent to the distance to the center of the tree. Then you would take a second shot, as
prompted, to the middle of the tree, for horizontal angle only. Note that for the elevation of the shot, you can use the
distance measurement or the angle measurement (second reading), and apply the vertical offset, if any, accordingly.
After both measurements are taken, the results are displayed. You are then returned to the dialog to take your next
offset.

Point (Plus/Minus)
: The Point Offset takes a shot and deducts or adds a distance relative to the line-of-sight in all
three directions (L/R, In/Out, Vertically Up/Down) using the dialog shown in the next figure.
 Before the shot, tap Read. After the shot, when the raw data is displayed in the lower left, tap Store. You will
remain in the command until you tap Close.
Repeat Shots Using Offsets
When taking multiple measurements in traffic or other conditions where you must move away quickly, one technique is