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Projection parameter problem

Topics: General Topics, SharpMap v0.9 / v1.x
Aug 17, 2010 at 12:50 PM

Hi All!

I use some coordinate system transformation to encrypt shape files: one of its steps to change their coordinate system, change its Central Meridian and so on. I transform back to its 'normal' coordsys on the fly - runtime. My encrypted coordsys is based on South_Pole_Lambert_Azimuthal_Equal_Area. It works, but as I see it does not parses the Central Meridian value changed by me, so the map is shifted by some kilometers.

string strSouthPole = "PROJCS[\"South_Pole_Lambert_Azimuthal_Equal_Area\",GEOGCS[\"GCS_WGS_1984\",DATUM[\"D_WGS_1984\",SPHEROID[\"WGS_1984\",6378137,298.257223563]],PRIMEM[\"Greenwich\",0],UNIT[\"Degree\",0.017453292519943295]],PROJECTION[\"Lambert_Azimuthal_Equal_Area\"],PARAMETER[\"False_Easting\",0],PARAMETER[\"False_Northing\",0],PARAMETER[\"Central_Meridian\",-127],PARAMETER[\"Latitude_Of_Origin\",-90],UNIT[\"Meter\",1]]";

SharpMap.CoordinateSystems.CoordinateSystemFactory pCoordSysFactory = new SharpMap.CoordinateSystems.CoordinateSystemFactory();
SharpMap.CoordinateSystems.ICoordinateSystem pSouthPole = pCoordSysFactory.CreateFromWkt(strSouthPole);

What could be the problem?

Thanks in advance.

Aug 18, 2010 at 9:22 AM

Hello tmatrai,

SharpMaps projection capabilities have been factored out to Proj.NET. You can download a more recent release, that might fix your problem. For to use that, you have to change all references from SharpMap.CoordinateSystems to ProjNET.CoordinateSystems.

Hth FObermaier