Ah, I think I see - you're using 'institution' the way 'station' or
'cast' might be used
in a collection of feature types. Do all the possible instance
variables (station, profile...)
need to have standard names, too?
I think what's confusing to some of us is that the concept of
coordinates is normally
about location in time and space; Is the use of the 'coordinates'
attribute really correct
here, or would it be more appropriate for the institution to be an
ancillary variable?
If I understand what you're conveying with this CDL, 'institution' it
looks really similar to
the NODC 'instrument' attribute. In that convention (built on CF)
'instrument' is a
specific adaptation of the 'ancillary variables' concept. The term in
the 'instrument'
attribute contains the name of a variable that describes the
instrument(s) that
collected the data. I think a similar approach - a new attribute that
conveys the
relationship between a "data variable" and an ancillary variable -
would be more
clear in this case.
Regards -
Nan
On 3/29/12 10:55 AM, Jonathan Gregory wrote:
> If source and institution become legal standard names, it means they
> can be used as the values of string-valued scalar or auxiliary
> coordinate variables. A scalar string coordinate variable is just a
> string (a 1D char array), so it would be functionally equivalent to a
> variable attribute. However, it could be an array of strings i.e. a 2D
> char variable, as you say:
>> is this meant
>> to be a 2D variable? It makes a lot of sense in that context.
> You could use this if the data had a dimension which corresponded to a source
> or institution e.g.
>
> dimensions:
> ninst=10;
> lat=180;
> lon=360;
> stringlength=30;
> variables:
> float ppn(ninst,lat,lon);
> ppn:standard_name="precipitation_flux";
> ppn:units="kg m-2 s-1";
> ppn:coordinates="institution";
> char institution(ninst,stringlength);
> institution:standard_name="institution";
> data:
> institution="GFDL", "MPI", "CSIRO", ...;
>
> Here, institution is an auxiliary coordinate variable.
>
> As you say,
>
>> this should
>> either be dimension (1) or share a dimension with one of the coordinates?
> This is described in sect 6.1 of the convention.
>
> Best wishes
>
> Jonathan
> _______________________________________________
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> CF-metadata at cgd.ucar.edu
> http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata
>
--
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* Nan Galbraith Information Systems Specailist *
* Upper Ocean Processes Group Mail Stop 29 *
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Received on Fri Mar 30 2012 - 08:19:13 BST
