[PROJ] geoid model from a geographic 2D

[Even Rouault]

Le 04/04/2024 à 14:34, Javier Jimenez Shaw a écrit :
> I have already asked the SLA in Singapore. Let's see what happens.
>
> If I identified it as "PROJ:SVY21_3D", and later they update EPSG 
> with, let's say, "EPSG:100"
> is there a way to say to proj.db that they ("PROJ:SVY21_3D" and 
> "EPSG:100") are the same thing, and that my added one "PROJ:SVY21_3D" 
> can be replaced by the new "EPSG:100"?
> I don't know if the table "alias_name" is for that purpose, or only to 
> updated names.

As far as I can remember, we don't have a way to express in the database 
that several entries are aliases of each other. The Topic 2 abstract 
model or WKT have provision to have several IDs per object, but we don't 
make use of that.  The alias_name table has a different purposes: 
handling the fact that object names may change, and to be able to match 
a deprecated/old name to the object that used to use it. Typically when 
processing WKT that don't have IDs.

-- 

http://www.spatialys.com
My software is free, but my time generally not.