The Transverse Mercator projection is similar to the Mercator Projection, except that the axis of the projection cylinder is rotated 90 degrees from the polar axis. This projection does not have the straight meridians and straight parallels of the Mercator projection, except for the central meridian, the two meridians 90 degrees away, and the equator. Nor does the Transverse Mercator projection have the straight rhumb lines of the Mercator projection; rather, it is a conformal projection. Scale is true along the central meridian or along two straight lines equidistant from and parallel to the central meridian.
The Transverse Mercator projection is the projection used in the State Plane Coordinate System for states with predominant north-south extent. It is also the geometric basis for the UTM Coordinate System.
Blue Marble Geographics uses a convention when assigning the sign to the convergence value of a point in a ProjectedCoordSys that uses this Projection. The conversion angle reported by the Projection::ConvergenceAtPoint method will be positive when the specified point lies north of the equator and west of the central meridian, or south of the equator and east of the central meridian. The convergence value will be negative when the point lies north of the equator and east of the central meridian or south of the equator and west of the central meridian.
The "TransverseMercator" Projection has the following Parameters:
|
Parameter Name |
Parameter String |
Units |
|
Longitude of the Center of the Projection |
central_meridian |
|
|
Latitude of the Origin of the Projection |
latitude_of_origin |
|
|
Scale Reduction Factor at the Center of the Projection |
scale_factor |
Double |
|
False Easting |
false_easting |
|
|
False Northing |
false_northing |