[PROJ] Matching EPSG:3005

[Nyall Dawson]

On Thu, 7 May 2020 at 05:46, Even Rouault <even.rouault at spatialys.com> wrote:

> Do not hesitate to give the full context for your question. I suspect this is related to https://github.com/qgis/QGIS/issues/36216 and Oracle WKT.

Correct! I'm mid way through a reply to that (but I'm blaming Oracle
here, not proj!)

> First, there's no particular effort in PROJ to deal with and "normalize" (that is use EPSG official names) Oracle WKT, so I'm not surprised that it doesn't work out of the box.

I guess I misunderstood the proj docs: "90% means that CRS are
equivalent, but the names are not exactly the same.". I assumed this
meant that a 90% match would ignore things like the
NAD83/GCS_North_American_1983 differences. But I'm guessing now that
there's only **some** names in the wkt which can vary?

> One thing that I can see, is that, as PROJ doesn't (yet ?) include an IA, "North American Datum 1983 (EPSG ID 6269)" and "North American Datum 1983" are considered to be different.

Can you clarify what IA stands for?

> Another more annoying reason is that when actually feeding the Oracle WKT in projinfo it reports "Unsupported conversion method: Albers Conical Equal Area", because it doesn't know this variant of the projection method name.

I did try with replacing this with the versions used by PROJ, but that
didn't alter the match at all.

Looks like Oracle is definitely at fault here. But for my own
curiosity, what else is missing in proj to allow identifying this
definition (aside for an alias to match "Albers Conical Equal Area")?

Nyall