[gdal-dev] Issue with Lambert Conformal projection with GDAL

[Frank Warmerdam]

Dmitry Kazimirov wrote:
> Greetings,
> 
> I currently trying to convert image data in grib2 format
> (specification is here if someone interested-
> http://www.weather.gov/forecasts/graphical/docs/grib_design.html, my
> datafeed is using 'Template 30' i.e. Lambert Conform Conic Projection)
> and rewarp it to other projection
> I have data about projection(they are sometimes changed)
> Lambert Conformal: (614 x 428) input WE:SN output WE:SN res 8 mode 8
> 
> 
> Lat1 12.190000 - latitude of first grid point
> Lon1 226.541000 - longitude of first grid point
> LoV 265.000000 - Orientation longitude (?)
> LatD 25.000000 - "Latitude where grid spacing is defined"
> Latin1 25.000000 Latin1, first secant latitude
> Latin2 25.000000 Latin2, second secant latitude (
> LatSP -90.000000 LonSP 0.000000 - Latitude and longitude of southern pole  (?)
> Dx 12190.528000 m  - Dx, X-direction grid length
> Dy 12190.590000 m - Dy, Y-direction grid length
> 
> GDAL Georeference's SetLCC require parameters
> SetLCC  	(  	double   	 dfStdP1,
> 		double  	dfStdP2,
> 		double  	dfCenterLat,
> 		double  	dfCenterLong,
> 		double  	dfFalseEasting,
> 		double  	dfFalseNorthing	
> 	) 		
> (uncommented at all)
> how I use my parameters to with GDAL?
> I understood that dfStdP1/P2 is 1st/2nd standard parallel(25.0000 in my case)
> What I should use fort dfCenterLat/Long?
> for falseEasting/Northing?
> Could anyone help?

Dmitry,

I don't have any good help.  I find the way that the GRIB folks describe
coordinate systems *very* hard to relate to normal GIS/Cartography
terminology.  I will note that the grib driver has this logic for
some LCC coordinate systems:

       case GS3_LAMBERT:
         oSRS.SetLCC(meta->gds.scaleLat1, meta->gds.scaleLat2,
                     0.0, meta->gds.orientLon,
                     0.0, 0.0); // set projection

I don't know if that helps at all or not.

Good luck,

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