[CF-metadata] Polar Stereographic Projection in CF

[John Caron]

IMHO, its important to store the actual projection. So the base coordinate 
system is x,y in units (typically) of "km on the projection plane". hopefully 
you are using a standard projection (eg polar stereographic), and then you use 
some well-known way of specifying the projection, eg FGDC. knowing the 
projection is necessary to allow full interoperability with GIS. This doesnt 
cost much, just 2 1D coordinate variables.

In addition, you might want to encode the lat/lon positions of each grid point, 
using the 2D coordinate axes as per section 5.2. This costs 2 2D variables in 
storage, which may or may not be small compared to the size of the file.

I dont see anywhere in the CF that standardizes how to specify the 
projection(?). I think its very important, perhaps it could be done for the next 
version ?



Mark A Ohrenschall wrote:

> Hello,
> 
> I'm wondering if I should follow section 5.2 of the CF Conventions in
> representing data that is in a polar stereographic projection. And at
> the risk of belaboring the obvious, are the two-dimensional coordinate
> variables respectively grids of latitude and longitude values for each
> grid cell in the poloar stereographic grid?
> 
> Thanks,
> 
> Mark
> 
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