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Spectra Precision Survey Pro v4.5 Ranger User Manual User Manual

Page 229

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GPS Coordinates in Survey Pro

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• Pick from Data Base. Select this choice to use a datum from

the coordinate system database.

• Custom

Molodensky

. Select this choice to enter a custom

three-parameter datum transformation.

• Custom

Similarity

. Select this choice to enter a custom seven-

parameter datum transformation.

3. Select the Azimuth type for the new map projection zone. Choices

are:
• North

Azimuth

. Select this choice to have a north azimuth grid.

• South

Azimuth

. This choice to have a south azimuth grid.

4. Select the Grid direction for positive coordinates in the new map

projection zone. Choices for grid direction are:
• North\East

Grid

. Select this choice to have coordinates increase

positive in the north and east directions.

• South\West

Grid

. Select this choice to have coordinates

increase positive in the south and west directions.

Note: The geodetic calculation engine and the Survey Pro coordinate

geometry engine are separate components. While the geodetic engine

can properly handle southwest grid systems, Survey Pro can only
operate on a northeast grid system. However, since a southwest grid

with a south azimuth is a mirror image of a northeast grid with a
north azimuth, Survey Pro can handle this configuration with the

following work around: You must set the Azimuth Type to North
Azimuth

on the Units card of the Job, Settings screen. You then treat

north as south and east as west, and the coordinates will be correct
for a southwest grid and south azimuth zone.

5. Tap Next to enter the zone parameters for the new map

projection.

6. Key in the five or six parameters for your new map projection

zone.

7. If your zone is Oblique Mercator Angle, the next screen is used to

pick the Origin and Azimuth values.