[mapguide-users] Webstudio and local coordinate systems

[Frank Warmerdam]

Bruce Dechant wrote:
> Michaela,
> 
> The problem is not related to webstudio but rather to the underlying coordinate system library used by MapGuide open source (MGOS), ie: PROJ4.
> PROJ4 does not support the coordinate system WKT you have below.
> 
> If you have the latest MGOS version (1.0.2) the web tier test pages have a "CheckWkt" page that uses the MapGuide API to check a coordinate system for you.
> 
> The default link is: http://localhost:8008/mapguide/mapagent/index.html
> 
> Then click on the "Coordinate System" link and select "CheckWkt"
> 
> Here is the result I get using MGOS with the WKT below:
> 
> 
> Coordinate System API: CheckWkt
> 
> OGC WKT:
> PROJCS["GK-S4-R95",GEOGCS["LL-RAUEN95",DATUM["RAUEN-95",SPHEROID["BESSEL",6377397,155,299,15281535],TOWGS84[582,0000,105,0000,414,0000,-1,040000,-0,350000,3,080000,8,30000000]],PRIMEM["Greenwich",0],UNIT["Degree",0.017453292519943295]],PROJECTION["Gauss_Kruger"],PARAMETER["false_easting",4500000,000],PARAMETER["false_northing",0,000],PARAMETER["scale_factor",1,000000000000],PARAMETER["central_meridian",12,00000000000000],PARAMETER["latitude_of_origin",0,00000000000000],UNIT["Meter",1,00000000000000]]

Bruce / Michaels,

I believe that Gauss_Kruger is just another name for Transverse_Mercator.
Trying changing:

    PROJECTION["Gauss_Kruger"]

to
    PROJECTION["Transverse_Mercator"].

I am open to suggestions on how to make OGR (used for PROJ.4 WKT
processing) more friendly with whatever the source of these WKT
strings is.  Is it copied from an ESRI .prj file?  Or is it standard
FDO WKT?  Perhaps we need methods to morph FDO WKT into OGR WKT and
the other way around, like I do for ESRI stuff now?  Or if there are
only a few oddities we could just aim to make the PROJ.4 translation
module handle some extra cases.

Best regards,
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I set the clouds in motion - turn up   | Frank Warmerdam, warmerdam at pobox.com
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