[esip-semanticweb] help with marking up WMS/WCS Capability docs?

John Graybeal graybeal at mbari.org
Thu Jul 16 16:40:16 EDT 2009


To the best of my knowledge, the use of role and arcrole[2] within  
xlink[1] to specify the purpose of the locator (href) attribute is  
limited only to requiring URIs. So you can create a vocabulary that  
describes any set of roles that you want.

John

[1] xlink semantics: http://www.w3.org/TR/xlink/#att-method
[2] Role, Arcrole, and Title: http://www.w3.org/TR/xlink/#link-semantics

On Jul 16, 2009, at 1:15 PM, Benno Blumenthal wrote:

> Hello Chris,
>
> I have not chimed in yet because I have not had a chance to review  
> the options for metadata in WMS, and I wanted to say something  
> precise.  Essentially if you just want controlled vocabulary, XML  
> and RDF are quite similar (i.e. if Brian's machine tag implies a  
> particular controlled vocabulary for the value, then you have  
> represented the information isomorphically to using RDF objects for  
> the concepts, and you can crosswalk).  If you want to relate two  
> objects, the xlink is XML's version of what is native in RDF, but I  
> think xlink is very limited as to the meanings of the connections,  
> whereas RDF lets the connection's meaning be specified explicitly  
> according to a convention.
>
>  But meanwhile, could you explain your example more fully -- I don't  
> understand what
>
> dataset=OMI_A_G
>
> means (you called it a relationship).
>
> Benno
>
> On Thu, Jul 16, 2009 at 3:55 PM, Christopher Lynnes <Chris.Lynnes at nasa.gov 
> > wrote:
> On Jul 15, 2009, at 6:52 PM, John Graybeal wrote:
>
> I am not deep in any one of these details, but I am a little familiar
> with all the possibilities you mention. So consider the following as
> notions to be verified:
>
> 1) RDFa won't fit gracefully into the OGC schema as written, because
> it is using a different set of elements (that is, it is tuned to the
> HTML elements). "To date, because XHTML is extensible while HTML is
> not, RDFa has only been specified for XHTML 1.1." [1]  The way it
> works is to add attributes, which must be in an RDFa-compatible XHTML
> schema if the document is to validate.
>
> 2) I wholeheartedly endorse the intent to use controlled vocabularies
> in a way that is compatible with the semantic web. All that should be
> necessary to do this is to find a suitable place where a URI can be
> placed.  Then you can create controlled vocabularies whose terms
> correspond to URIs. There is extensive guidance on this topic at the
> MMI site [2].  I do not know of any reason these approaches would be
> incompatible with the ESIP ontologies.
>
> 3) The way OOSTethys [1] chose to add more specific descriptions/
> references to SensorML/O&M was through the use of xlink, which is
> supported in the OGC schema. Examples are on the OOSTethys site. As
> far as I know, this is the most used OGC practice to meet this need to
> date. (Because I don't know of any other particular recommendation.)
> Note that if a standard allows a name to be specified as a URI (which
> most of the SWE standards do, yes?), that is another place where the
> sensor web.
>
>
> Can you point me to any specific examples (i.e., URLs to files)?
>
> I'm having some difficulty seeing how a *relationship*, like  
> 'dataset=OMI_A_G' can be expressed with the xlink or URI...
>
> Thx,
>
>
>
> On Jul 15, 2009, at 12:53 PM, Christopher Lynnes wrote:
>
> Greetings!
>
> Over in the Air Quality Cluster, we are experimenting with using
> some kind of structured markup / tagging of OGC WMS and WCS
> capabilities documents (inside <Keyword> elements) to allow us to do
> structured searches on the documents.  An example might be, "give me
> the layers where Dataset = 'OMI_AI_G'". Seehttp://wiki.esipfed.org/index.php/WMS_GetCapabilities#WMS_GetCapabilities_Layer_Description
>
> Thing is, we figure if we are going to try to implement this kind of
> markup with a quasi-controlled vocabulary, we should do it in such a
> way that it is compatible with or even leverages the semantic web.
> We have pondered a machine tags approach, e.g.,
> <Keyword>esip:dataset=OMI_AI_G</Keyword>.  (A link to an initial
> attempt of a WMS that includes the current keyword encoding: http://webapps.datafed.net/AIRNOW.ogc?service=wms&request=getCapabilities&version=1.1.1)
> .
>
> Alternatively, we have heard RDFa mentioned for microformats, though
> mostly in the context of XHTML.  Can this be applied to OGC's XML
> and if so, how?
>
> Can the ESIP Semantic Web cluster provide a recommendation or
> suggestion in how to move forward that would be:
> (a) flexible and extensible,
> (b) compatible with the evolving ESIP datatype and services ontology
> and
> (c) lightweight and easy to use?
> --
> Christopher Lynnes             NASA/GSFC, Code 610.2
> 301-614-5185
>
> _______________________________________________
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>
>
> John
>
> --------------
> John Graybeal   <mailto:graybeal at mbari.org>  -- 831-775-1956
> Monterey Bay Aquarium Research Institute
> Marine Metadata Interoperability Project: http://marinemetadata.org
>
>
> --
> Christopher Lynnes             NASA/GSFC, Code 610.2          
> 301-614-5185
>
> _______________________________________________
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> esip-semanticweb at rtpnet.org
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>
>
>
> -- 
> Dr. M. Benno Blumenthal          benno at iri.columbia.edu
> International Research Institute for climate and society
> The Earth Institute at Columbia University
> Lamont Campus, Palisades NY 10964-8000   (845) 680-4450
> _______________________________________________
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John

--------------
John Graybeal   <mailto:graybeal at mbari.org>  -- 831-775-1956
Monterey Bay Aquarium Research Institute
Marine Metadata Interoperability Project: http://marinemetadata.org



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