Spectra Precision Survey Pro v4.2 GPS - Manual (Page 13)

Survey Pro GPS Quick Start Guide 11
Mapping Plane Zones and Ground Scale
If your horizontal projection mode is Ground – TDS
Localization
, you do not need to worry at all about map
projections, datums, or scale for ground distances. The
default projection and localization adjustment take care of
that for you.
If you are using Mapping Plane mode, you need to select a
map projection from the database, and if you going to
measure distances on the ground with an EDM, you need to
apply a scale factor. Applying a scale factor can be done in
one of two ways :
¾ You can use the selected mapping plane zone, with or
without a localization adjustment, and apply a
combined scale factor. When you use mapping plane
and a combined scale factor, the horizontal distances
are scaled to the map grid. To set the combined scale
factor, go to the Job | Settings | Surveying screen,
check the Use Scale box and tap Compute Scale. Select
your conventional occupy point and follow the wizard
instructions.
¾ You can use the selected mapping plane zone, with or
without a localization adjustment, and setup a Ground
Coordinates system. The Ground Coordinate system
will scale the mapping plane coordinates to ground
level. When you use Ground Coordinates, the
horizontal distances are 1:1 to the grid. To set a
Ground Coordinates system, go to the Survey |
Projection screen and tap Setup Ground Coordinates….
Follow the wizard instructions to set up Ground
Coordinates and adjust all of the job file points to the
new system.
Data Collection
Data Collection Settings
Use the Job | Settings | Measure Mode screen to control how
the receiver collects data, what raw data to write for each
point, and what criteria to check before accepting GPS
positions.