[OSRS-PROJ] PROJ 4.4.3 - about epsg...

Bart Adriaanse B at rt.nl
Fri Apr 20 15:58:47 EDT 2001

----- Original Message -----
From: "Frank Warmerdam" <warmerdam at pobox.com>
To: <osrs-proj at remotesensing.org>
Sent: Friday, April 20, 2001 8:44 PM
Subject: Re: [OSRS-PROJ] PROJ 4.4.3 - about epsg...
> Bart,
> I believe the current logic in my code for generating the EPSG mapping is
> to only generate a datum definition for coordinates systems where EPSG
> one, and only one route from that datum directly to WGS84.  This means
> alot of interesting datums end up not being if for instance multiple
> approximations exist.

This makes sense, in the case of the dutch system the right datum
transformation is in there somewhere but my understanding of how all tables
are related is not good enough to figure out what could be the problem, with
the changes made to the data base structure in version 5 of epsg it seems to
become even more difficult to find the right things in there...

> For now I would encourage you to file a bug report in Bugzilla, and I will
> try to come up with a mechanism to automatically patch selected coordinate
> systems based on an override file when doing the automated EPSG to PROJ.4
> translations.

I'll wait with that untill i have actually verified the 7 parameter shift so
i can advise you on what is best to use for the Dutch system...

> It must be stressed that the epsg definition file isn't well tested, and
> I would encourage anyone running into problems with it to report them.

Obviously, i am sure we all appreciate how tricky the epsg to proj
translation must have been...

Best regards,

Bart Adriaanse
The Netherlands

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