Uh, I leave the details to someone who knows better :) - it is a while since I checked, and it might indeed be underspecified right now.

To the best of my knowledge, there is only one widely used coordinate system for each Mars and Titan. I might be wrong. But in the worst case we would need to specify the default system for either.

I am not saying that the whole thing is not a problem - I am just saying that the data model, as spec'ed and implemented, has a space for solving it. It is obvious that without support in the UI the whole thing is slightly moot anyway.

On Fri, Oct 7, 2016 at 2:23 PM Jan Macura macurajan@gmail.com wrote:

2016-10-07 20:34 GMT+02:00 Denny Vrandečić vrandecic@gmail.com:

Wikidata allows to set a coordinate system - it is called a globe or coordinate system - on every coordinate. This would be the natural place to specify whether it is WGS84 or GDA94 or another system. Most of them are Q2, which, as per data model, is indeed WGS84

Hi Denny,

can you be more specific about this? So when there is no explicit value in the *globe* parametre of GlobeCoordinate, then it is treated as Q2 (this corelates with the dumps and every RDF serialization)? It would imply geographic coordinates (not the same as WGS84!!). Or is it considered to be specifically WGS84, which is Q11902211? And how you tell the coordinate system for other celestial bodies like Q111 (Mars) or Q2565 (Titan)?

Thanks a lot Jan _______________________________________________ Wikidata mailing list Wikidata@lists.wikimedia.org https://lists.wikimedia.org/mailman/listinfo/wikidata