Developer
Feb 27, 2011 at 12:35 AM

In the proj 4.8 library there is a +axis parameter. This parameter may be used to change the axis orientation (such as when x axis goes from east to west instead of west to east)
According to
proj 4 documentation:
'e'  easting 'w'  westing  an x/longitude with the opposite sign to normal. 'n'  northing 's'  southing  a y/latitude with the opposite sign to the normal. 'u'  up  normal z 'd'  down  a z/elevation with the opposite sign to the normal.
So, a normal coordinate system is defined as "+axis=enu". This is the default and it may be omitted in the normal case. Some variations:
"end"  Normal in x/y but the Z is a depth rather elevation. "neu"  reversed x/y axes, for instance +proj=latlong +axis=neu would truely be a latitude/longitude coordinate system. "wsu"  A coordinate system with the sign of x and y negated as is used for transverse mercator south orientated.
In the Esri string, these parameters are also supported as "Y_Scale" (1.0 or 1.0), "X_Scale" (1.0 or 1.0) and "XY_Plane_Rotation" (90.0 if x/y axis are reversed)
If the group agrees, may I add "Axis" as a new property of DotSpatial.Projections.ProjectionInfo?
Regards,
Jiri

