Re: ISA Core Location Vocabulary

Thanks, Ghislain.

Actually, the approach adopted in the Core Location Vocabulary was to allow
the use of any kind of geometry encoding/representation (so, yes, Frans,
also the NeoGeo voc is supported, even though it is not included in the
examples). The point was that there was no agreement in the group about the
best way to represent geometries. Rather, the group recognised that this
depends on the specific use case.

I wonder whether which are views in the CG on this issue.

Cheers,

Andrea







On Fri, Dec 20, 2013 at 3:07 PM, Ghislain Atemezing <
auguste.atemezing@eurecom.fr> wrote:

> Hi Frans,
>
>  A completely different thing: I see that the Location Core Vocabulary
>> does not define a new way of encoding geometry, but rather permits the
>> encoding specified in GeoSPARQL and Basic Geo. Was NeoGeo ever
>> considered too? One consideration may be that the world at large will
>> not be helped by having many different encodings for geometry. I think I
>> would prefer just an encoding of WKT, but without including the (URI of)
>> the coordinate reference system (CRS). I believe the SRS should be a
>> separate entity, to be applicable to a geometry, to a collection of
>> geometries, or to a dataset.
>>
> +1. This is definitively a way to go and with the colleagues at
> IGN-France, we are finishing two vocabularies that basically reuse NeoGeo,
> GeoSPARQL to re-define the existing semantics of POINT by taking into
> account what you just pointed out..
>
> 1- A vocab for CRS: http://goo.gl/UchRcy, that will be tied to the
> publication of at least the list of CRS maintained at IGN.
> 2- A yet another vocab for geometry, where we allow to have different CRS
> for a geometry. See http://goo.gl/nsJfei.
>
> You can play with this application, "Perfect School"[1] where from the
> initial dataset in LAMBERT93, we provide for each resource two different
> encoded values for the geometries.
>
> For example, we have queries like this
>
> [ ?s rdf:type aiiso:School ;
>         geom:geometry ?loc ;
>         ecole:nature ?nature .
>
>     ?loc geom:coordX  ?lat ;
>         geom:coordY ?lng ;
>         geom:systCoord  ignfr:wgs84g . # here we specify the CRS, e.g:
> ignfr:ntflamb2e
> ]
>
> where we will publish all the CRS in this domain space ignfr: <
> http://data.ign.fr/id/ignf/systemecoordonnees/>
>
> More to come when all the current issues are solved and the vocabs are in
> a stable version...
>
> Happy Holidays to everyone.
>
> [1]  http://semantics.eurecom.fr/datalift/PerfectSchool/
>
> --
> Ghislain Atemezing
> EURECOM, Multimedia Communications Department
> Campus SophiaTech
> 450, route des Chappes, 06410 Biot, France.
> e-mail: auguste.atemezing@eurecom.fr & ghislain.atemezing@gmail.com
> Tel: +33 (0)4 - 9300 8178
> Fax: +33 (0)4 - 9000 8200
> Web: http://www.eurecom.fr/~atemezin
> Google+:http://google.com/+GhislainATEMEZING
> Twitter:@gatemezing
>
>


-- 
Andrea Perego, Ph.D.
European Commission DG JRC
Institute for Environment & Sustainability
Unit H06 - Digital Earth & Reference Data
Via E. Fermi, 2749 - TP 262
21027 Ispra VA, Italy

DE+RD Unit: http://ies.jrc.ec.europa.eu/DE

----
The views expressed are purely those of the writer and may
not in any circumstances be regarded as stating an official
position of the European Commission.