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Geo vocabulary - relating geo:Point values to other entoties

From: Graham Klyne <graham.klyne@zoo.ox.ac.uk>
Date: Wed, 18 Mar 2009 12:25:54 +0000
Message-ID: <49C0E852.7000700@zoo.ox.ac.uk>
To: danbri@danbri.org, Semantic Web <semantic-web@w3.org>
CC: Sebastian Rahtz <sebastian.rahtz@oucs.ox.ac.uk>
Hi Dan (or anyone),

I've a question about the geo vocabulary (http://www.w3.org/2003/01/geo/) that 
you still seem to be shepherding (well, as recently as 2 years ago, it seems :)

Is there a common vocabulary term that can be used to attach a geo:Point to an 
object, e.g. to say that some place includes a given point.  We're looking to 
combine the geo: vocabulary with CIDOC-CRM [4], which has its own concept for a 
coordinate entity that is distinct from geo:Point, but for which geo:Point would 
be a reasonable qualifier.

[[
<rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#">
   <E53.Place xmlns="http://purl.org/NET/crm-owl#"
       rdf:about="http://clas-lgpn2.classics.ox.ac.uk/placeid/LGPN_12790">
     <P87.is_identified_by>
       <E47.Place_Spatial_Coordinates>

         <what-property-goes-here???>

           <geo:Point xmlns:geo="http://www.w3.org/2003/01/geo/wgs84_pos#">
             <geo:lat>25.49395234082177</geo:lat>
             <geo:long>37.05405819595916</geo:long>
           </geo:Point>

         </what-property-goes-here???>

       </E47.Place_Spatial_Coordinates>
     </P87.is_identified_by>
   </E53.Place>
</rdf:RDF>
]]

You give an example <based_near> from FOAF, but that seems not very generic.  It 
doesn't feel like a good idea if every vocabulary that employs geo: terms has to 
also invent its own terms to link to them.

My suggestion:  <geo:has_point> indicating that the place or region that is the 
domain of this property contains the <geo:Point> location that is the range of 
the property.

I did think of treating CRM's <E47.Place_Spatial_Coordinates> [2] as a 
superclass of <geo:Point>, but I worry that creates an relationship between CRM 
and geo entities that may not always be true (as in "Hey, You Kids, Get Off My 
Lawn!" [3]?).

There still a bit of an issue lurking here as the CRM entity is not itself a 
place, but a form of place identifier (as can be seen by browsing up the class 
hierarchy from [2]), so maybe my thought about <geo:has_point> would still miss 
the point (pun accidental).

So: did you have any thoughts about the ways in which geo:Points relate to other 
entities?

#g
--

[1] http://www.w3.org/2003/01/geo/

[2] 
http://www8.informatik.uni-erlangen.de/IMMD8/Services/cidoc-crm/docu/081216/classes/E47.Spatial_Coordinates.html

[3] http://lists.w3.org/Archives/Public/www-rdf-interest/2000Sep/0162.html

[4] http://cidoc.ics.forth.gr/, 
http://www8.informatik.uni-erlangen.de/IMMD8/Services/cidoc-crm/documentation.html

-- 
Graham Klyne
Image Bioinformatics Research Group
Department of Zoology, University of Oxford
South Parks Road, Oxford OX1 3PS, UK
E-mail: <Graham.Klyne@zoo.ox.ac.uk>
Direct phone: +44-(0)1865-281991
Departmental fax: +44-(0)1865-310447
Web: http://ibrg.zoo.ox.ac.uk/
      http://antiparos.zoo.ox.ac.uk/
      http://imageweb.zoo.ox.ac.uk/
Received on Wednesday, 18 March 2009 17:47:43 GMT

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