Spectra Precision Survey Pro v5.0 - Manual (Page 124)

Custom Molodensky: Choose this option to use a custom 3-parameter datum transformation, with either a
custom ellipsoid or a data base ellipsoid.
Custom Similarity: Choose this option to use a 7-parameter datum transformation, with either a custom
ellipsoid or a data base ellipsoid.
Grid and Azimuth Parameters: is where you select the grid azimuth and the positive coordinate direction. The
options are:
North Azimuth: Set a north azimuth for your new zone.
South Azimuth: Set a south azimuth for your new zone.
North/East Grid: Set the coordinates increasing positive in the north, east direction
South/West Grid: Set the coordinates increasing positive in the south, west direction.
Key In Zone - Mapping Plane Parameters
The Key In Zone Mapping Plane Parameters screen is used to enter the values for the map projection zone.
The parameters required depend on the zone type. They will include:
Central Longitude / Latitude: Enter the geodetic origin of the map projection.
False Northing / Easting: Enter the coordinate offsets at the origin of the map projection.
Scale factor: Enter the scale factor of the map projection.
N / S Parallel: Enter the north and south standard parallels of the map projection.
Azimuth: Enter azimuth of the central line of the map projection.
Key In Zone – Oblique Mercator Settings
The Key In Zone Oblique Mercator screen is sued to set extra parameters when the Zone Type is set to Oblique
Mercator Angle.
Azimuth At: Enter the convention for projection azimuth. The options are:
Equator
Center of Projection
Origin At: Enter the convention for projection azimuth. The options are:
Equator
Center of Projection
Rectify Coordinates: Set if the coordinates are rectified. Coordinates are ‘rectified’ if the local plane is rotated by the
azimuth angle of the central meridian of the projection so that grid North lines up with geodetic north at the origin.
Key In Zone - Ellipse
The Key In Zone Ellipse screen is used to set or create an ellipse for a new datum. This screen is only displayed when
Datum Type is Molodensky or Similarity.
Choose an ellipse for the new zone.
Ellipse from Data Base: Choose this option to use the selected data base ellipsoid.
Key in Ellipse: Choose this option to enter the values for the custom ellipsoid.
Survey Pro Help 5.00
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