[OSGeo-Standards] PROJJSON OGC Community Standard Submission?

[Luí­s Moreira de Sousa]

Hi Howard,

thank you for the heads up, the initial message slipped past me. 

I am one of the people working on the CRS web ontology Rob mentioned, meant for joint approval by the W3C and the OGC. We are coming close to a first draft, you may follow that work here:
https://github.com/opengeospatial/ontology-crs

This web ontology does nor propose a new domain model, rather a semantic web counterpart to existing specifications. Namely, it is compatible with:
- ISO 19111
- IGN CRS ontology
- PROJ4RDF ontology
- PROJ data model

Within the PROJ4RDF initiative, Timo Homburg developed tools for the seamless transformation between WKT and RDF. Therefore we'll largely get a JSON-LD serialisation for free. Eventually, this web ontology will allow for the creation of a semantically accurate, machine-readable, on-line CRS registry.

Now, if indeed PROJJSON is not compatible with ISO 19111 then we might need some extra alignment. This should also mean PROJJSON cannot be (completely?) translated into WKT, and would not be entirely compatible with this coming W3C/OGC CRS web ontology. Do I read this correctly? Have you documented these divergences from ISO 19111 in a new domain model of some kind?

Regarding the application procedure, possibly the best is to submit a motion to the OSGeo Board. That would lend formal support by OSGeo. However, it might be useful to square these efforts together. As Rob mentioned, STAC is at best a counter-example here. I hope we can take this forwards in a better coordinated way.  

Regards.

--
Luís Moreira de Sousa
Mastodon: https://mastodon.social/@luis_de_sousa
URL: https://ldesousa.codeberg.page

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On Wednesday, 12 November 2025 at 03:43, Howard Butler via Standards <standards at lists.osgeo.org> wrote:

> No takers, interest, or guidance on this topic?
> 
> > On Oct 31, 2025, at 12:37 PM, Howard Butler howard at hobu.co wrote:
> > 
> > Hello,
> > 
> > The PROJ project plans to submit PROJJSON as an OGC Community Standard. The application document was initiated three years ago [1] by myself and Even Rouault, but we were waiting to see if the OGC CRS SWG would build upon PROJJSON to create a JSON based encoding of CRS.
> > 
> > To date, no draft has been published, the survey at the previous OGC meeting was ambiguous about how the organization would move forward, and if the CRS SWG chooses to revisit ISO 19111 conceptual model enhancements and their reflection through a JSON CRS definition, that work will in all likelihood be backwards and forwards incompatible with PROJJSON. Given the current situation, we would like to move forward with PROJJSON as a Community Standard.
> > 
> > In the interim since we initiated the submission, PROJJSON adoption has continued to grow. STAC was recently recognized as a OGC Community Standard at the Boulder Members Meeting [2], and its Projection Extension references PROJJSON. GeoParquet 1.1 [3] uses PROJJSON as its CRS definition, Parquet references PROJJSON as a possible definition in its spatial types[4], and Zarr is looking at it for its geo-proj Zarr extension [5].
> > 
> > We believe it makes sense to resume the application process for PROJJSON to be also recognized as a community standard. Even has prepared an update of the application at https://github.com/OSGeo/projjson-submission/pull/3.
> > 
> > Does OSGeo want to be mentioned as one of the submitting organizations? If so, what's the process for a project to submit one of its works to OSGeo as a Community Standard? A successful motion raised on this mailing list?
> > Kind regards,
> > 
> > Howard and Even
> > 
> > [1] https://github.com/OSGeo/projjson-submission
> > [2] https://www.ogc.org/announcement/ogc-announces-publication-of-the-spatiotemporal-asset-catalog-community-standards/
> > [3] https://geoparquet.org/releases/v1.1.0/
> > [4] https://github.com/apache/parquet-format/blob/master/Geospatial.md
> > [5] https://github.com/zarr-experimental/geo-proj
> 
> 
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