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Re: GeoSpatial vocabularies

From: Frans Knibbe | Geodan <frans.knibbe@geodan.nl>
Date: Wed, 08 Aug 2012 14:40:21 +0200
Message-ID: <50225E35.9070905@geodan.nl>
To: Thomas Bandholtz <thomas.bandholtz@innoq.com>
CC: public-lod@w3.org
Hello Thomas,

Why do you think an RDF version of OGC Catalog Services is needed? Don't 
the regular ways of describing datasets suffice?

One reason I can think of is that we desperately need some way of 
describing the spatial resolution (level of detail, level of 
generalization) for datasets. I did suggest this to the GeoSPARQL 
working group, but the idea was rejected. But perhaps the concept of 
resolution of a dataset (or a single data resource) is not limited to 
geospatial data. Other data about real world objects could be captured 
or modelled at different levels of detail too. I really wonder if there 
already is something out there that could be used to indicate the 
resolution of spatial data.


On 8-8-2012 12:36, Thomas Bandholtz wrote:
> Phil,
> very good idea.
> Is anybody aware of some RDF for OGC Catalog Services?
> If not I will tinker a draft quite soon.
> Best regards
> Thomas
> Am 06.08.2012 14:46, schrieb Phil Archer:
>> Having been involved with a number of conversations recently, and
>> being aware of many more, I am proposing a new Community Group around
>> vocabularies for describing locations.
>> See http://www.w3.org/community/groups/proposed/#locadd
>> Background
>> ==========
>> This is hardly a new idea and the last thing I want to do is to fall
>> into the XKCD trap [1]. Nevertheless, we have different organisations
>> having similar but separate conversations at the moment, mostly born
>> of different use cases and perspectives. This is normal but I think
>> some sort of coordination could be beneficial.
>> =========
>> The OGC has completed work on GeoSPARQL [2]. This is favoured by the
>> likes of (UK mapping agency) Ordnance Survey and has been produced
>> primarily by geospatial experts with an interest in linked data.
>> NeoGeo
>> ======
>> A community effort has produced NeoGeo [3]. This is favoured by the
>> likes of (French mapping agency) IGN and has been produced primarily
>> by linked data experts with an interest in geospatial data.
>> The primary difference between GeoSPARQL and NeoGeo is in the way they
>> handle point, line and polygon literals. Both enjoy significant
>> support and implementation experience.
>> =======
>> Is a European Commission Directive that legally obliges the Member
>> States of the European Union to publish environmental and geospatial
>> data using a common set of standards which are under various stages of
>> development [4].
>> ISA Programme Location Core Vocabulary
>> ======================================
>> Produced by a working group chaired by the team responsible for the
>> development of INSPIRE under the auspices of a different part of the
>> European Commission, this very lightweight vocabulary includes
>> properties and classes for describing locations and for recording
>> addresses in a manner conformant with INSPIRE - a feature not shared
>> by vCARD for example. Now a work item of the W3C Government Linked
>> Data WG [5], the vocabulary needs further community review and
>> refinement [6].
>> schema.org
>> ==========
>> Includes basic classes and properties for locations including:
>> - addresses (a clone of vCard) http://schema.org/PostalAddress
>> - lat/long (a clone of WGS84) http://schema.org/GeoCoordinates
>> - geoShape (including boc, circle, line & polygon)
>> http://schema.org/GeoShape
>> It inherits things like name, URL and description from
>> schema.org/Thing which are at least analogous to things like
>> Geographic Names and Geographic Identifiers.
>> schema.org includes containedIn but not, AFAICT, borders etc. The
>> schema.org location properties seem closely linked with event
>> vocabulary. Classes include Mountain, Body of Water, Continent etc.
>> The current list of proposed extensions to schema.org [7] does not
>> include anything in this space and there is no (visibly active)
>> discussion associated with schema.org and location.
>> W3C Point of Interest
>> =====================
>> I'm sorry to say that the Points of Interest WG [8] seems to have hit
>> the buffers so that the March 2012 draft [9] looks like being as far
>> as it gets. This just at a time when more and more data is being
>> published, a lot of it related to locations and, well, points of
>> interest. The ideas behind the POI WG remain as important as ever but
>> it seems that a new focus is necessary if that work is to be leveraged
>> effectively.
>> Standards bodies
>> ================
>> OGC and W3C are both willing to help if required but what actually
>> *is* required? That's what the proposed community group is to find
>> out. When we know that, we can look at where any work should be done.
>> Like any membership organisation, both W3C and OGC put the wishes of
>> their members first. Both bodies are very willing to work together.
>> Possible outcomes
>> =================
>> One possible outcome is a standard that is backwards compatible with
>> GeoSPARQL and NeoGeo and that combines aspects of both. The danger
>> there is that this would lead to an over-complex standard that could
>> never be fully implemented - which is about as big a pointless waste
>> of time as can be imagined. However, the two are close and common
>> ground shouldn't be hard to find.
>> At the other extreme is that everyone carries on in in their own way
>> and, well, people can pick and choose. This seems less than ideal to
>> me. If interoperability between data sets is important then we need to
>> make some effort to coordinate.
>> The gaps seem to be around linked-data friendly INSPIRE standards,
>> particularly wrt addresses, and in handling geometry literals that can
>> be huge (no one is talking about yet another way to define points
>> lines and polygons btw!).
>> What I hope the proposed group could achieve is:
>> - consensus on the use cases/gaps that need be filled;
>> - at least a rough solution that takes full account of the existing
>> work highlighted here.
>> If that can be done, the GLD WG's charter would allow it to take this
>> through the W3C Recommendations Track, assuming the continued support
>> and interest of the community. The WG itself does not have the
>> resources and geospatial expertise to see this through on its own.
>> If this interests you, do please join the Community Group at
>> http://www.w3.org/community/groups/proposed/#locadd and post your ideas.
>> Thank you
>> Phil.
>> [1] http://xkcd.com/927/
>> [2] http://www.opengeospatial.org/standards/geosparql
>> [3] http://geovocab.org/doc/neogeo/
>> [4] http://inspire.ec.europa.eu/index.cfm/pageid/2
>> [5] http://www.w3.org/2011/gld/
>> [6] http://philarcher.org/isa/locn-v1.00.html although officially I
>> should point you to http://joinup.ec.europa.eu/asset/core_location/home
>> [7] http://www.w3.org/wiki/WebSchemas/SchemaDotOrgProposals
>> [8] http://www.w3.org/2010/POI/
>> [9] http://www.w3.org/2010/POI/documents/Core/core-20111216.html
Received on Wednesday, 8 August 2012 12:40:59 UTC

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