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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* Nan Galbraith        Information Systems Specailist *
* Upper Ocean Processes Group            Mail Stop 29 *
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