sync PROJJSON with OGC updates to the WKT spec: keywords `definingTransformation` and `anchorEpoch`

[nsajko]

The PROJJSON JSON schema has no equivalent to the WKT keyword definingTransformation, if I'm not wrong. Am I wrong?

Would it be possible to either document this discrepancy (if there is one), or add a DefiningTransformation to PROJJSON?

[nsajko]

It seems this is a recent addition to the OGC WKT specification, so I guess PROJJSON just didn't have time to catch up? The version 2.0.8 of the WKT spec, dated 2022-07-15, added the keywords definingTransformation and anchorEpoch.

I wonder what should be done with such nodes when translating WKT to PROJJSON? Just drop them before outputting? Or is there already a way to represent those in PROJJSON?

[rouault]

I wonder what should be done with such nodes when translating WKT to PROJJSON? Just drop them before outputting?

yes

Or is there already a way to represent those in PROJJSON?

no. That could be added if there was a strong need for it, but it isn't clear to me right now what would be the practical advantage of bringing that piece of metadata

[nsajko]

OK, feel free to close then, or maybe keep open for reference, in case someone else asks the same question.