The partially good news is that if enough information (dwc:geodeticDatum) is given in a Darwin Core-based record, geo:lat/lon can be determined from it. More disturbing to me is that anyone would think geo:lat/lon alone is sufficient for any application, as it carries no notion of uncertainty and therefore fitness for use. Add dwc:coordinateUncertaintyInMeters (or even dwc:coordinatePrecision if you must) to the mix and I would be much happier.


On Sun, Aug 8, 2010 at 11:26 PM, <Garry.Jolley-Rogers@csiro.au> wrote:
Hi Jim,
       Thanks. Had this aside to read in detail later.  I think John is right... As same value with different constraints mean different interpretations are possible and seems to be the key thing. How are the values to be interpreted.

G

-----Original Message-----
From: Jim Croft [mailto:jim.croft@gmail.com]
Sent: Monday, 9 August 2010 4:12 PM
To: Alexander, Paul (PI, Black Mountain); Harvey, Paul.W (PI, Black Mountain); Jolley-Rogers, Garry (PI, Black Mountain); Cawsey, Margaret (CES, Crace); Greg Whitbread
Cc: tuco@berkeley.edu
Subject: Fwd: [tdwg-tag] time and space namespaces in Darwin Core

Did you catch this thread on tdwg-tag?  It is an almost exact mirror
of the conversations we have be having in the taxon profile space, but
involving the specimen locational data.

>>>From John's comments it would appear he is not prepared to accept the
geo: and dwc: lat/long as 'exact match' because, although they are the
same values, they have different constraints (or more precisely one
one has a constraint and one doesn't).

I wouldn't have picked it but this looks like a case for 'closematch'.

jim


---------- Forwarded message ----------
From: John Wieczorek <tuco@berkeley.edu>
Date: Mon, Aug 9, 2010 at 3:56 AM
Subject: Re: [tdwg-tag] time and space namespaces in Darwin Core
To: joel sachs <jsachs@csee.umbc.edu>
Cc: tdwg-bioblitz@googlegroups.com, tdwg-tag@lists.tdwg.org


There is actually no equivalency between dwc:decimalLatitude and
geo:lat  because geo:lat is specified to represent the latitude in the
WGS84 spatial reference system and dwc:decimalLatitude has no such
such restriction.

On Fri, Aug 6, 2010 at 10:08 AM, joel sachs <jsachs@csee.umbc.edu> wrote:
>
> On Fri, 6 Aug 2010, Hilmar Lapp wrote:
>
> > Shouldn't the RDF for DwC link DwC:lat to geo:lat (using some subtype
> > or better yet equivalency relation)? And shouldn't hence Linked Data
> > browsers be able to use DwC:lat in the same way as geo:lat?
> >
>
> Yes. But no Linked Data browser I'm aware of applies
> owl:equivalentProperty assetions before rendering the data. (In fact, most
> do no reasoning at all.) I agree that, whatever our default display,
> it should include the appropriate mapping statements, either via an
> rdfs:seeAlso or similar link, or directly in the document.
>
>
> Joel.
>
>
> >       -hilmar
> >
> > On Aug 6, 2010, at 11:01 AM, joel sachs wrote:
> >
> >> All,
> >>
> >> When representing observation records in RDF, there are advantages
> >> to using Dublin Core and Geo (http://www.w3.org/2003/01/geo/
> >> wgs84_pos#)
> >> namespaces where possible. For example, if we use DC:date, and
> >> geo:lat, geo:long, instead of DwC:eventDate, DwC:lat, and DwC:long,
> >> then Linked Data browsers can automatically map the records, plot
> >> them on a timeline, etc.
> >>
> >> My question is: What are the disadvantages to doing this? (For
> >> example, is this going to break someone's DwC validator?)
> >>
> >> Thanks -
> >> Joel.
> >>
> >
> > --
> > ===========================================================
> > : Hilmar Lapp  -:- Durham, NC -:- informatics.nescent.org :
> > ===========================================================
> >

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