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Lambert Conformal Conic 2SP

Oct 25, 2011 at 1:41 PM

I have some clients using raster maps with this projection.

Currently there is not a 2SP variant in the DotSpatial.Projections.Transforms namespace.

I have copied the LambertConformalConic class and renamed it, set the Name parameter and add it into the _transforms in the TransformManager class and it appears to work.

The quesiton is that is it actually working i.e. are the LambertConformalConic and LambertConformalConic2SP transformations actually the same and if not what would I need to change to get it to be correct.



Oct 25, 2011 at 4:12 PM

I asked a colleague of mine about this and this is what he had to say:

Actually most LCC state plane systems ARE 2SP (2 standard parallels), and I think folks just refer to that as the default LCC. The alternative (less common) is 1SP and a scale factor (instead of the 2nd SP). I’m pretty sure the DS code handles both cases fine. 

Oct 25, 2011 at 5:37 PM

I had the same sort of problem this summer (see My fix was just to change the LambertConformalConic constructor from:

        public LambertConformalConic()
            Name = "Lambert_Conformal_Conic";
            Proj4Name = "lcc";


        public LambertConformalConic()
            Name = "Lambert_Conformal_Conic;Lambert_Conformal_Conic_2SP";
            Proj4Name = "lcc";

Oct 26, 2011 at 9:01 AM

Ok thanks for that, it would be good if a developer could tweek the LCC class to include sstanton's solution.

Oct 26, 2011 at 7:38 PM

I can make the change. Kellison, do you see any problems this might cause?

Jan 26, 2012 at 9:01 PM

It appears that Lambert_Conformal_Conic_1SP is not presently supported.