Re: ISA Core Location Vocabulary

Hi Raphael,

Our use case is a very simple one. We offer APIs for city data, and
obviously one fundamental aspect in our API is the use of geo-referenced
data.

We have our coordinates encoded in GeoSPARQL (e.g., for a district in
Madrid see [1]), using WKT for the definition of polygons, with the
definition of the coordinate reference system there (e.g.,
"<http://www.opengis.net/def/crs/EPSG/0/23030> POLYGON
((440414.613499999978 4473164.381099999882, Š"). We use at least two of
these coordinate systems for the geometries that we are encoding. Besides,
por points, we use the simple WGS84 vocabulary.


Internally, we are also encoding the CRS as a literal value, for easier
access to it and to speed up SPARQL queries. But we would prefer relying
on URIs rather than literal values.

Oscar



[1] 
http://datos.localidata.com/recurso/territorio/Provincia/Madrid/Municipio/m
adrid/Distrito/02?_view=coordenadas (you will need to register at
datos.localidata.com and get an API Key to get access to it). And sorry,
currently only in Spanish.




-- 

Oscar Corcho
Ontology Engineering Group (OEG)
Departamento de Inteligencia Artificial
Facultad de Informática
Campus de Montegancedo s/n
Boadilla del Monte-28660 Madrid, España
Tel. (+34) 91 336 66 05
Fax  (+34) 91 352 48 19






El 22/12/13 16:50, "Raphaël Troncy" <raphael.troncy@eurecom.fr> escribió:

>Dear Oscar,
>
>> When do you plan to have this KB of coordinate systems already publicly
>> available? We would love to be able to reuse it.
>
>This is clearly on our todo list! With the Linking Geospatial Data
>workshop coming up, we will definitively push the publication of such a
>resource early next year.
>
>Our early motivation is that France is using different coordinate
>systems for geolocalizing geographical objects, such as: Lambert93 in
>the Metropolitan area, RGFG95 in Guyanne (French Antilles), RGR92 in
>Réunion (near Madagascar), RGM04 in Mayotte, RGSPM06 in
>St-Pierre-et-Miquelon, etc. The problem is that often, the CRS is
>implicit and you have of course to interpret differently the lat/long
>values given in a spreadsheet.
>
>Besides a vocabulary and a knowledge base, we are also about to publish
>a REST service that can convert data represented in on CRS to WGS84.
>
>Can you describe what is your use case with LocaliData ?
>Cheers.
>
>   Raphaël
>
>-- 
>Raphaël Troncy
>EURECOM, Campus SophiaTech
>Multimedia Communications Department
>450 route des Chappes, 06410 Biot, France.
>e-mail: raphael.troncy@eurecom.fr & raphael.troncy@gmail.com
>Tel: +33 (0)4 - 9300 8242
>Fax: +33 (0)4 - 9000 8200
>Web: http://www.eurecom.fr/~troncy/
>

Received on Sunday, 22 December 2013 18:55:02 UTC