[Esip-documentation] ACDD comments --

Mon Sep 22 14:55:37 EDT 2014

Nan,
Excellent point.   I think all CF datasets that don't have a
`featureType` identified would be treated as `grid`.   That would be
okay, wouldn't it?

On Mon, Sep 22, 2014 at 2:48 PM, Nan Galbraith via Esip-documentation
<esip-documentation at lists.esipfed.org> wrote:
> Hi All -
>
> I mostly agree with Rich;  the 2 sets of terms are redundant - at
> best.
>
>> Reading this, I think we should just modify ncISO to read featureType
>> rather than cdm_data_time and deprecate its use in favor of
>> featureType
>
>
> But! My concern is that by using the featureType attribute you
> are identifying your file as a discrete sampling geometry file,
> and there are still MANY data sets that don't fit that. Lots of
> data is published as data(T,Z,Y,X) - not permitted in DSG files.
> Here's a CF email from Jonathan on the subject:
>
>
>
> -------- Original Message --------
> Subject:        [CF-metadata] featureType attribute (was CF-1.6 DSG
> clarification: time series & lat/lon coordinates)
> Date:   Tue, 3 Dec 2013 21:06:03 +0000
> From:   Jonathan Gregory <j.m.gregory at reading.ac.uk>
> To:     cf-metadata at cgd.ucar.edu
>
>
>> Dear Nan
>>>
>>> >  Does the presence of a featureType attribute indicate that a file
>>> >  uses the DSG
>>> >  "machinery" and should therefore follow the guidelines of limited axes
>>> > that
>>> >  are spelled out in chapter 9?
>>
>> featureType can have only those values which are shown in Table 9.1. Each
>> value means that the data has a particular geometry, as shown in the
>> table.
>> Your data
>>>
>>> >  float seatemp(time, depth, lat, lon)
>>
>> does not have one of those geometries. In words, it isn't apparently a set
>> of timeseries, or a set of profiles, or any other of the possibilities.
>> It's
>> a variable with four independent spatiotemporal axes. This is the "usual"
>> type of gridded domain which CF has always supported. In the discrete
>> sampling geometries the spatiotemporal axes aren't all independent.
>> Therefore I
>> don't think you can use the featureType attribute with your data as it
>> stands.
>
>
> Cheers -
> Nan
>
>
>> On Fri, Sep 19, 2014 at 5:16 PM, John Graybeal via Esip-documentation
>> <esip-documentation at lists.esipfed.org>  wrote:
>>>
>>> I'm going to start replying to some of these on separate threads.
>>>
>>> I'm consolidating the issues into the Google spreadsheet as we discussed
>>> on
>>> the call, will publish that 'shortly' (when done).
>>>
>>> By the way, sorry for the delayed post of my mail responding to Bob, that
>>> mail was written yesterday and got hung up.
>>>
>>> On Sep 18, 2014, at 11:50, Bob Simons - NOAA Federal<bob.simons at noaa.gov>
>>> wrote:
>>>
>>> cdm_data_type should not be tied to
>>>
>>>
>>> http://www.unidata.ucar.edu/software/thredds/current/tds/catalog/InvCatalogSpec.html#dataType
>>> which is out-of-date and obsolete
>>>
>>> Are you sure? I thought several on this list were still using it.
>>>
>>> They probably are. That doesn't make it right. Unidata has created
>>> several
>>> sets of terms over the years. They haven't retracted the old versions.
>>> I'm
>>> not saying what the right list of terms is, just that that list is
>>> out-of-date. Until Unidata and CF get their act together, it is better
>>> for
>>> ACDD to not pick a winner.
>>> Please read this entire exchange:
>>> http://mailman.cgd.ucar.edu/pipermail/cf-metadata/2010/048519.html
>>> which clearly indicates the John Caron (if he is in practice the decider)
>>> says about cdm_data_type, which clearly goes beyond the list ACDD is
>>> seeking
>>> to enshrine.
>>>
>>>
>>> ACDD picked that winner in a previous version, and I reviewed the CF
>>> thread
>>> a year ago while trying fix this issue. Because there are many data sets
>>> that followed ACDD then (and some still use the cdm_data_type, per Rich),
>>> we
>>> didn't deprecate the existing attribute. But we did clarify in the
>>> definition that there is another attribute called featureType in CF
>>> (which
>>> is the outcome of the thread you cited, I believe).
>>>
>>> I'd be happy to move cdm_data_type to Suggested instead of Recommended, I
>>> think it should no longer be recommended. And maybe that wording needs to
>>> be
>>> improved, and the featureType attribute explicitly added? But I don't
>>> think
>>> we should redefine its meaning in a way that would break the previous
>>> uses.
>>>
>>> John
>>>
>>>
>>> _______________________________________________
>>> Esip-documentation mailing list
>>> Esip-documentation at lists.esipfed.org
>>> http://www.lists.esipfed.org/mailman/listinfo/esip-documentation
>>>
>>
>>
>
>
> --
> *******************************************************
> * Nan Galbraith                        (508) 289-2444 *
> * Upper Ocean Processes Group            Mail Stop 29 *
> * Woods Hole Oceanographic Institution                *
> * Woods Hole, MA 02543                                *
> *******************************************************
>
>
>
>
> _______________________________________________
> Esip-documentation mailing list
> Esip-documentation at lists.esipfed.org
> http://www.lists.esipfed.org/mailman/listinfo/esip-documentation

-- 
Dr. Richard P. Signell   (508) 457-2229
USGS, 384 Woods Hole Rd.
Woods Hole, MA 02543-1598