Re: [netcdfgroup] Encode an azimuthal equidistant projection in NetCDF conversion

• To: icloud <khakpour.m@xxxxxx>
• Subject: Re: [netcdfgroup] Encode an azimuthal equidistant projection in NetCDF conversion
• From: Elizabeth Fischer <rpf2116@xxxxxxxxxxxx>
• Date: Wed, 10 Feb 2016 07:20:49 -0500

Use the proj.4 library and pyproj
On Feb 10, 2016 5:23 AM, "icloud" <khakpour.m@xxxxxx> wrote:

>
> I'm trying to do Azimuthal Equidistant in CF-compliant NetCDF, but I
> didn't get the correct projection.
> If you compare the first two information (gdalinfo) you see there is no
> `AUTHORITY` and also `PROJCS`, `GEOGCS`, `DATUM`, `SPHEROID` are unknown.
>
> I followed this link to set the set the projection:
> Mapping from CF Grid Mapping Attributes to CRS WKT Elements
> <https://github.com/cf-convention/cf-conventions/wiki/Mapping-from-CF-Grid-Mapping-Attributes-to-CRS-WKT-Elements>
>
> This is the original projection which I want to save it to NetCDF.
>
>     Size is 8000, 8000
>     Coordinate System is:
>     PROJCS["Azimuthal_Equidistant",
>         GEOGCS["WGS 84",
>             DATUM["WGS_1984",
>                 SPHEROID["WGS 84",6378137,298.257223563,
>                     AUTHORITY["EPSG","7030"]],
>                 AUTHORITY["EPSG","6326"]],
>             PRIMEM["Greenwich",0],
>             UNIT["degree",0.0174532925199433],
>             AUTHORITY["EPSG","4326"]],
>         PROJECTION["Azimuthal_Equidistant"],
>         PARAMETER["latitude_of_center",53],
>         PARAMETER["longitude_of_center",24],
>         PARAMETER["false_easting",5837287.81977],
>         PARAMETER["false_northing",2121415.69617],
>         UNIT["metre",1,
>             AUTHORITY["EPSG","9001"]]]
>     Origin = (4800000.000000000000000,1800000.000000000000000)
>     Pixel Size = (75.000000000000000,-75.000000000000000)
>
>
>
>
>
> and this is what I got:
>
>
>    Size is 8000, 8000
>     Coordinate System is:
>     PROJCS["unnamed",
>         GEOGCS["unknown",
>             DATUM["unknown",
>                 SPHEROID["Spheroid",6378137,298.257223563]],
>             PRIMEM["Greenwich",0],
>             UNIT["degree",0.0174532925199433]],
>         PROJECTION["Azimuthal_Equidistant"],
>         PARAMETER["latitude_of_center",53],
>         PARAMETER["longitude_of_center",24],
>         PARAMETER["false_easting",5837287.81977],
>         PARAMETER["false_northing",2121415.69617]]
>     Origin = (4799602.500000000000000,1800037.500000000000000)
>     Pixel Size = (75.000000000000000,-75.000000000000000)
>
>
>
>
> here is the code that I extracted the projection:
>
>     # Extract Projection info from tiff
>     ds = gdal.Open('sample.tiff')
>     prj = ds.GetProjection()
>     srs = osr.SpatialReference(wkt=prj)
>
>
>     # Create container variable for CRS
>     crso = nco.createVariable('crs', 'i4')
>     crso.grid_mapping_name = 'azimuthal_equidistant'
>     crso.projected_crs_name = srs.GetAttrValue('PROJCS')
>     crso.geographic_crs_name = srs.GetAttrValue('GEOGCS')
>     crso.horizontal_datum_name = srs.GetAttrValue('DATUM')
>     crso.latitude_of_projection_origin = srs.GetProjParm(
> 'latitude_of_center')
>     crso.longitude_of_projection_origin = srs.GetProjParm(
> 'longitude_of_center')
>     crso.false_easting = srs.GetProjParm('false_easting')
>     crso.false_northing = srs.GetProjParm('false_northing')
>     crso.longitude_of_prime_meridian = 0.0
>     crso.semi_major_axis = 6378137.0
>     crso.inverse_flattening = 298.257223563
>
>
>
> Does someone know how to get the correct projection?
>
>
>
>
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• References:
  • [netcdfgroup] Encode an azimuthal equidistant projection in NetCDF conversion
    • From: icloud