Missing GeoSPARQL WKT coordinate system

[VladimirAlexiev]

@jyrkioraskari The example below was produced from a Malgrat BIM model CentreCultural_AMM_v02.ifc by @Gonsco.
@nataschake Please put it in https://github.com/Accord-Project/Malgrat (IFC and Turtle file).
Goncal, is it ok to give Jyrki access to that BIM file and github project?

inst:wall_c771b999-41ea-407a-ab23-92d5459716eb
        rdf:type bot:Element , beo:Wall
        lbd:containsInBoundingBox  inst:space_9cb09d4a-d0a1-4705-885b-510e96282a6a .

inst:space_9cb09d4a-d0a1-4705-885b-510e96282a6a
      rdf:type bot:Space;
      omg:hasGeometry            inst:space_9cb09d4a-d0a1-4705-885b-510e96282a6a_geometry.

inst:space_9cb09d4a-d0a1-4705-885b-510e96282a6a_geometry
        geo:asWKT           "MULTIPOINT Z((-10443.56550743269 11257.269568646563 4750.0), (-765.7077325990435 19602.768600278832 8750.0))" .

This space includes 34 building elements (walls etc) so I think it encompasses quite a lot of the building.

Let's look at the geometry:
By default, the coordinate system of WKT is WGS-84 (EPSG 4326). But the coordinates above are obviously easting/northing.

Goncal, can you tell us how is the IFC geo-referenced?

Malgrat urban planning (parcels) use EPSG 25831. The coordinates of that building are as follows (converted at https://epsg.io/transform#s_srs=4326&t_srs=25831&x=2.7414317&y=41.6458244):

• WGS 84 (EPSG 4326): 2.7414317, 41.6458244
• EPSG 25831: 478467.64328690973, 4610486.0223075785

If EPSG 25831 is also the correct CRS for the IFC, then the literal should be like this:

geo:asWKT "<http://www.opengis.net/def/crs/EPSG/0/25831> MULTIPOINT Z((-10443.56550743269 11257.269568646563 4750.0), (-765.7077325990435 19602.768600278832 8750.0))"^^geo:wktLiteral

[VladimirAlexiev]

Goncal said that the IFC file also uses EPSG 25831 for geo-referencing.