I don't think the metadata structure needs to be terribly
complex, in most cases. Changes to instruments (either a
new instrument, a change to the sample scheme, or some
kind of change to calibrations, etc) partway through could
be a problem, but that's true in xml too.

John G is right, we often lose access to the network at sea;
but even without that consideration, NetCDF is supposed to
be self-documenting, and we should be able to come up with
some strategies for including fairly complex metadata in the
files. 

I like the ancillary variable route because it seems straightforward
and flexible.
  • Data variables can share one or more ancillary variables, very useful for something like an ADCP record.
  • Ancillary variables can have data types.
  • Ancillary variables can have dimensions that make them self-explanatory.
Cheers - Nan


On Aug/05/2011 2:08 PM, Lowry, Roy K. wrote:
Hi John,

We seem to have a difference of perception in the fragility of Web access to the average scientist.  Certainly, I was assuming ships had virtually the same level of internet access as I have at home (if not in the lab) based on my experience of the NERC ships.  However, if lack of internet access becomes an issue then we need to look at URI resolution to physical XML files sitting with the NetCDF.

Cheers, Roy.

________________________________________
From: John Graybeal [[email protected]]
Sent: 05 August 2011 17:57
To: Lowry, Roy K.
Cc: [email protected]; [email protected]
Subject: Re: [CF-metadata] per-variable metadata?

On Aug 5, 2011, at 09:27, Lowry, Roy K. wrote:

Hi Nan,

At the risk of being shot for herecy, I maintain the belief that in the current technological environonment packing everything inside the straightjacket container of a physical file is an anachronism.  <snip>  So, I would have an attribute in the CF file holding a permanent identifier that is guaranteed to be resolvable from now until eternity into an XML file delivering usage metadata.
I agree with the first statement, because 'everything' is a long list indeed.  The world of linked open data agrees too, I expect.

But with respect to *usage* metadata, I wonder.  Because the storage of complex data for perpetual access on the web is not a solved problem, and not everyone has access to the entire web, or at least every metadata provider for every file they are working with, all the time.  So then you're stuck, until the ship gets back or the DSL line is up or the hosting site finishes its weekly maintenance, or someone goes back and resuscitates some old system that had the metadata years or decades before.

John-- 
This message (and any attachments) is for the recipient only. NERC
is subject to the Freedom of Information Act 2000 and the contents
of this email and any reply you make may be disclosed by NERC unless
it is exempt from release under the Act. Any material supplied to
NERC may be stored in an electronic records management system.


-- 
*******************************************************
* Nan Galbraith                        (508) 289-2444 *
* Upper Ocean Processes Group            Mail Stop 29 *
* Woods Hole Oceanographic Institution                *
* Woods Hole, MA 02543                                *
*******************************************************


_______________________________________________
CF-metadata mailing list
[email protected]
http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata

Reply via email to