Spectra Precision Survey Pro v4.6 Recon and Nomad User Manual - Manual (Page 133)

Mapping Plane Scale Factor
123
Combined Scale Factor
You should select Use a single combined scale factor
option when using a single combined scale factor to
reduce all your total station measurements. The scale
factor might be provided for you, in which case you
simply enter the value in the Combined Factor field and
tap to return to the Job > Settings > Surveying screen,
otherwise you can calculate the combined scale factor as
described below.
A map zone must be set up before a combined scale
factor can be calculated. To configure a map zone, tap
the bottom button to open the Select Coordinate System
screen. This button is labeled Change Map Zone if a map
zone is already configured or Set Map Zone if a map zone
is not yet configured. Configuring a map zone is
described in the Mapping Plane Select Zone section of
this manual, starting on Page 251.
Tap Calculate Scale to open the Scale Calculator wizard, which is used
to compute the combined scale factor based on the current map zone.
If a map zone is not currently configured, the Select Coordinate
System screen will open first where you can set one up.
Enter a reference point in the Select Point field and tap
Calc. Scale>.