Hi,
----- Original Message -----
From: "Bentley, Philip" <philip.bentley at metoffice.gov.uk>
Date: Wednesday, August 3, 2011 11:17 am
Subject: Re: [CF-metadata] the need to store lat/lon coordinates in a CF-compliant netCDF file
> Hi Jon,
>
> > I've been following this thread with great interest. For me
> > it boils down to this question:
> >
> > - Is the datum always known by the data provider?
Tthe World Ocean Database (
http://www.nodc.noaa.gov/OC5/WOD09/pr_wod09.html ), which is creating by aggregating and standardizing datasets collected over a long period of time, has some datasets which go all the way back to the time of James Cook. Some of these datasets, I am certain, have datum which is not known. But, I think the provider could still give a best guess for what the datum could have been with adequate qualification instead of leaving it to the user to select arbitrary datum.
Upendra
>
> Almost certainly, but by a comparatively small number of individuals
> within an organisation I would guess. However - and here's the
> blocker -
> probably not by many/enough of the people who have the (let's be
> frank)unglamorous job of compiling metadata for large volumes of
> spatial data.
>
> >
> > If the answer is "yes" then I see no reason to omit the datum
> > (and plenty of reasons to include it). If there *are*
> > situations where the datum is genuinely unknown or undefined
> > then we need to express this clearly too so users can beware.
> >
> > (Previous posts mentioned GCMs as possible situations where
> > the datum is unknown - is this really true? Surely there is
> > always a sphere with a known radius on which coordinates are based?)
> >
> That would be my assumption also - that the raw facts are always
> known.
> In my experience the problem tends to be organisational rather than
> technical. Few organisations seem to employ staff whose lapel badge
> reads 'Spatial Metadata Operative'. Which is, I realise, a pretty lame
> excuse. Anyhows, I'm drifting off topic.
>
> Cheers,
> Phil
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Received on Wed Aug 03 2011 - 10:08:07 BST
