[Proj] finding proj descriptions

Martin Desruisseaux martin.desruisseaux at geomatys.com
Tue Oct 16 06:09:40 EST 2018

Le 16/10/2018 à 12:17, Roger Oberholtzer a écrit :

> I used to use http://epsg.io/ to find the proj strings for projections
> of interest. I see that the site now only provides an OGP XML
> description.
That site should be taken carefully anyway. Despite its name, epsg.io is
unrelated to EPSG. The only official and authoritative online source of
EPSG definitions is http://epsg-registry.org/ (or http://www.epsg.org/
for downloading the database). Some Well Known Texts provided by epsg.io
are in departure with authoritative EPSG definitions: for example most
geographic CRS which are defined with different axis orders, or the
Google projection (http://epsg.io/3857) which is defined with a wrong
projection method (it causes an error of about 30 km at the latitude of

I have heard that if EPSG was not a non-profit committee, they may have
taken legal action for asking epsg.io to change their name (disclaimer:
I'm of course not speaking in the name of anyone at IOGP). That web site
is of course free to provide the CRS definitions they want. It is the
illusion that those definitions show EPSG authoritative definitions
which is problematic.


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