[Esip-documentation] Fwd: ACDD questions

Fri Apr 19 16:33:54 EDT 2013

---------- Forwarded message ----------
From: Derrick Snowden - NOAA Federal <derrick.snowden at noaa.gov>
Date: Fri, Apr 19, 2013 at 4:02 PM
Subject: Re: [Esip-documentation] ACDD questions
To: ngalbraith at whoi.edu

Hi Nan,

I hope this is the place to discuss ACDD because it looks like the
conversation is beginning.  Some comments interspersed below.

On Fri, Apr 19, 2013 at 3:39 PM, Nan Galbraith <ngalbraith at whoi.edu> wrote:

>  Hi all -
>
> Is this now the right list to discuss the ACDD? I'm highly motivated to
> confirm some details and definitions, since I'm working on an update
> to the oceansites format specification, and we're trying to adopt ACDD.
>
> And, what is now the definitive page describing ACDD? The geo-ide page
> includes a field that's not on the unidata page, geospatial_bounds.
> I'm not sure if that's intended to be in addition to the min/max
> lat/long attributes, or an alternative.  The geo-ide page is at
>
> https://geo-ide.noaa.gov/wiki/index.php?title=NetCDF_Attribute_Convention_for_Dataset_Discovery
> and I guess I'd like to know if that has been (or is going to be) replaced
> by something on the ESIP site?
>

I would like to develop a new landing page that includes some introductory
material discussing the purpose of ACDD and perhaps some discussion of how
things work.  The current page on the NOAA wiki immediately launches into
mappings which I agree is important, but shouldn't be the first page people
see.  I also think we need another page that serves as the versioned list
of attributes (if it's not on the list, it's not part of the convention)
and that each attribute contain a well written clear definition.  I think
the definitions we have now need to be improved.  By committing to using
ESIP for this conversation, I think we're committing to using the wiki as
the definitive source of ACDD information.

Ted, is there any reason we cannot begin creating pages now?  Anything we
should know before we start about ESIP wiki conventions?  I wouldn't want
to come in to our new environment and start messing up a well laid out plan
for the wiki.

>
> Has anyone who's using a keywords attribute figured out a decent scheme?
> I'm going to assume that  we're talking about describing the 'science'
> data
> with these, not data sources or feature types.
>
> I can't say we've found a decent scheme but I will say that I don't want
to limit ourselves too much. I'd like to be able to include keywords for
things like platform type and feature type since I feel like it's an
element of discovery.  I think the challenge is to find a way to associate
multiple "keyword_vocabulary"s.  I think that ncISO currently pulls out CF
standard names from the variable attributes and includes them as keywords
in the transformed ISO record.  Including them again as keywords seems like
unnecessary duplication.  I can see a need for including multiple keyword
vocabularies.  IOOS has been publishing vocabularies and maps between
existing vocabularies at MMI <http://www.mmisw.org/ont/ioos>.  I'd like to
be able to reference more than one of those.  It's not clear how to do that
yet.

> My question is whether these should be listing all the data variables in a
> file,
> or the general field of the data - e.g.
>  ''air_temperature, relative_humidity, rainfall_rate..."
> vs
> "OCEANOGRAPHY: GENERAL: Marine meteorology" (or just "Marine meteorology")
>
> Last point - I notice that the NetCDF-U people are identifying files that
> follow their
> spec (for uncertainty)  using a more standard approach than ACDD; they add
> UW-1.0 as a term in the Conventions attribute.  Should we consider this
> too, in
> place of the Metadata_Conventions attribute?
> Conventions = "CF-1.5 UW-1.0 ACDD-1.0"
>

I like the clarity of this approach.

>
> ACDD is certainly not the only metadata convention, and NUG recommends
> putting
> all the conventions in one attribute.
>
> Thanks - Nan
>
>
> Our discussion today about mailing list names has borne fruit!
>
>  Great work and thanks to our ESIP colleagues!
>
>
> --
> *******************************************************
> * Nan Galbraith        Information Systems Specialist *
> * Upper Ocean Processes Group            Mail Stop 29 *
> * Woods Hole Oceanographic Institution                *
> * Woods Hole, MA 02543                 (508) 289-2444 *
> *******************************************************
>
>
>
>
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>

-- 
Derrick Snowden
System Architect, US IOOS <http://www.ioos.noaa.gov>
1100 Wayne Ave, Suite 1225
Silver Spring, MD 20912
+1 301 427 2464 (o), +1 301 427 2073 (f)

Find us on Facebook <http://www.facebook.com/usioosgov>

-- 
Derrick Snowden
System Architect, US IOOS <http://www.ioos.noaa.gov>
1100 Wayne Ave, Suite 1225
Silver Spring, MD 20912
+1 301 427 2464 (o), +1 301 427 2073 (f)

Find us on Facebook <http://www.facebook.com/usioosgov>
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