Re: [CF-metadata] Re: GDAL NetCDF driver and projection.

• To: "Rich Signell" <rsignell@xxxxxxxx>
• Subject: Re: [CF-metadata] Re: GDAL NetCDF driver and projection.
• From: "Denis Nadeau" <denis.nadeau@xxxxxxxxx>
• Date: Mon, 1 May 2006 13:35:39 -0400

Hi Rich,

...

Denis -- It seems that you are doing something slightly different than
ESRI.  Are you using ESRI WKT, OpenGIS WKT in your NetCDF files, or
something different.  It would be nice to see an example of these as
well.  Is your primary objective to have a NetCDF file that can be used
as input and output from GDAL, but able to handle any georeferencing
information that GDAL is capable of producing?

My primery objective is indeed to have a NetCDF file that can be used as input 
and ouput from GDAL.  And I want the NetCDF driver to handle any georeferencing 
information that GDAL is capable of producing.

I am using OpenGIS WKT in my NetCDF files.  I can easily support ESRI PE 
strings, but I do not know at this point if ESRI PE strings is equivalent to 
ESRI WKT.  Here is an example of GDAL NetCDF file.  It is still a prototype at 
this point and needs to be polished.

I used NetCDF CF-1 convention to create the file.

netcdf CratedNetcdf {
dimensions:
       x = 515 ;
       y = 515 ;
variables:
       char lambert_conformal_conic ;
               lambert_conformal_conic:Northernmost_Northing =
15448.6987687312
;
               lambert_conformal_conic:Southernmost_Northing = -
15451.301231268
8 ;
               lambert_conformal_conic:Easternmost_Easting =
15488.384688517 ;
               lambert_conformal_conic:Westernmost_Easting = -
15411.615311483 ;

               lambert_conformal_conic:spatial_ref = "PROJCS[\"LCC
E000
\",GEOGCS[\"NAD27\",DATUM[\"North_American_Datum_1927\",SPHEROID[\"Clarke
1866\",6378206.4,294.9786982139006
,AUTHORITY[\"EPSG\",\"7008\"]],AUTHORITY[\"EPSG\",\"6267\"]],PRIMEM[\"Green
wich\",0],UNIT[\"degree\",
0.0174532925199433],AUTHORITY[\
"EPSG\",\"4267\"]],PROJECTION[\"Lambert_Conformal_Conic_2SP\"],PARAMETER[\"
standard_parallel_1\",
33.90363402777778],PARAMETER[\"standard_parallel_2\",33.6252900
2777778],PARAMETER[\"latitude_of_origin\",33.76446202777778
],PARAMETER[\"central_meridian\",-117.4745428888889
],PARAMETER[\"false_easting\",0],PARAMETER[\"false
_northing\",0],UNIT[\"metre\",1,AUTHORITY[\"EPSG\",\"9001\"]]]" ;

              lambert_conformal_conic:GeoTransform = "-15411.6 60 0
15448.70-60 " ;
               lambert_conformal_conic:grid_mapping_name =
"lambert_conformal_conic" ;
               lambert_conformal_conic:standard_parallel_1 = 33.90363f ;
               lambert_conformal_conic:standard_parallel_2 = 33.62529f ;
               lambert_conformal_conic:latitude_of_projection_origin =
33.76446f ;
               lambert_conformal_conic:central_meridian = -117.4745f ;
               lambert_conformal_conic:false_easting = 0.f ;
               lambert_conformal_conic:false_northing = 0.f ;

       byte Band1(y, x) ;
               Band1:coordinates = "lon lat" ;
               Band1:grid_mapping = "lambert_conformal_conic" ;
               Band1:long_name = "GDAL Band Number 1" ;
               Band1:_FillValue = -9999. ;

// global attributes:
               :Conventions = "CF-1.0" ;
               :AREA_OR_POINT = "Area" ;
}

• References:
  • RE: GDAL NetCDF driver and projection.
    • From: Steve Kopp
  • Re: GDAL NetCDF driver and projection.
    • From: Denis Nadeau