`reference_ellipsoid_name` not used in netcdf grid mappings

[mraspaud]

Hi,

It looks like fimex doesn't load the reference_ellipsoid_name item from netcdf/cf, so that we could directly specify eg: reference_ellipsoid_name: WGS84. Instead, one has to provide the semi_major_axis and one of semi_minor_axis or inverse_flattening iiuc. Since these names are for supported in proj4, it would be nice if we could pass this information directly.

[heikoklein]

Hi,
I agree that we should add the newer CF-features. This feature is from CF-1.7 draft, and I'm not able to understand it. It refers to the ellipsoid.csv table on https://github.com/cf-convention/cf-conventions/wiki/Mapping-from-CF-Grid-Mapping-Attributes-to-CRS-WKT-Elements , which does not exist? And the ellipsoid.csv tables I have (from gdal), don't contain WGS-84.
So, without the mapping table from names to parameters, this will be difficult. We could just support WGS-84 and forget about others? I voted against EPSG codes in CF a while ago, so I'm not very keen on it.
Heiko

[mraspaud]

ellipsoid.csv is an attachment at the bottom of the page, and the link is : https://raw.githubusercontent.com/wiki/cf-convention/cf-conventions/csv/ellipsoid.csv
WGS84 is the most important nowadays it seems (in our field at least), so we can start with that indeed.

[mraspaud]

I modified the ellipsoid document and added a column with corresponding proj4 ellps name. Hope it helps !
ellipsoid.txt (it's in csv format)