Dear Jonathan,
> I would say it is the treatment of time which is anomalous.
I guess time has an arbirtrarily-large set of datums (you can pick
anything you like for the "since" attribute, i.e. the epoch) so the
standard name approach couldn't be used for time unless you restrict
the number of epochs that are possible. But there are a limited
number of vertical datums so this wouldn't result in a standard name
explosion.
Whichever approach is taken the tools have to do pretty much the same
job, i.e. parse a string and (potentially) reference to a CRS
elsewhere in the file.
Regards, Jon
On Thu, Aug 7, 2008 at 10:53 AM, Jonathan Gregory
<j.m.gregory at reading.ac.uk> wrote:
> Dear Jon
>
>> standard_name="time"
>> units="seconds since 1970-01-01"
>>
>> i.e. the units specify the coordinate system. By analogy we could
>> have, for the vertical coordinate:
>>
>> standard_name="depth"
>> units="metres below geoid" (or "metres below reference ellipsoid") etc.
>
> I would say it is the treatment of time which is anomalous. COARDS did have
> some other uses of units to identify quantities, but CF deprecates this. We
> took the view that the quantity should be described by other attributes, and
> the units should be general-purpose udunits-compliant ones.
>
> So I think the best course is to propose some precise standard names for
> your needs.
>
> Best wishes
>
> Jonathan
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>
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Received on Thu Aug 07 2008 - 04:12:45 BST
