[PROJ] Seeking clarification on PROJ support for temporal transformations

[Nyall Dawson]

On Wed, 28 Aug 2019 at 01:26, Even Rouault <even.rouault at spatialys.com> wrote:
>
> > But, if I understand correctly, WKT2:2018 would be the ultimate answer
> > to this, in that it would allow us to specify the epoch of a dataset
> > as an integral part of the data's CRS definition (which it is).
>
> Not sure to understand your "what it is", but pedantically, the epoch of the
> dataset is not part of the CRS definition. Anyway...

Well -- I think it IS a fundamental part of the definition, of equal
importance to other parameters such as false easting/northing. Without
the epoch information the coordinate data becomes meaningless, and
it's required in order to accurately position them. While it would
theoretically be possible to store this information somewhere else in
a dataset's metadata, it's such an integral part of the CRS that
shoving it right into the CRS definition is the right way forward...

Nyall


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