[postgis-devel] Adding 4D support to asGeoJson

Even Rouault even.rouault at spatialys.com
Wed Jan 31 14:20:16 PST 2018

On mercredi 31 janvier 2018 16:39:57 CET Alexandre Lessard wrote:
> If we take a look into the OpenGIS specification of a simple featue
> http://www.opengeospatial.org/standards/sfa Section the OGC
> describe the 4 possible dimensions of a geometry and the fourth
> dimension is describe as a measurement. Continuing on that road, ISO 31,
> 31-1 and ISO 80000-3 define the units of measurements and they are all
> numerical (https://en.wikipedia.org/wiki/ISO_80000-3 Sorry for the
> wikipedia link I can only find the places to buy the standard
> documentation not the proper definition).
> So knowing that we can now ask for an errata on the rfc7946 to define
> properly the forth dimension. We can even go deeper since the SFA also
> define that a 3 dimension geometry can be XYZ or XYM so we would need to
> add a way to distinct the 2 to respect that standard properly.
> So i suggest to do the work now for the XYZM format and propose to the
> ietf modification to the RFC to respect the OGC SFA standard.

As far as I know, the omission of the 4th dimension in RFC7946 was done on purpose. Sean 
Gillies cc'ed might be able to confirm


Spatialys - Geospatial professional services
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.osgeo.org/pipermail/postgis-devel/attachments/20180131/69e80eaf/attachment.html>

More information about the postgis-devel mailing list