Jean-Claude Repetto wrote:
Please read this thread on the PROJ.4 ML :
<http://www.nabble.com/epsg-parameters-td16447986.html>
This is Frank Warmerdam's answer :
>
> The problem is that if EPSG offers more than one transformation to
> WGS84 for a datum, the automated translation gives up and offers none
> of them preferring for the user to make the decision themselves.
>
I think it would be better to create the srs.db database directly from
the EPSG database.
Hi Jean-Claude,
if I read that nabble-thread, my conclusion is: it's at this moment not
possible to do a 1to1 translation for the EPSG-db to srs.db because of
the simple fact that one epsg can have more set's of parameters which
are 'valid/best' for different parts of the world.
I think there are some options though:
- add the definition YOU prefer for this specific epsg to your local
srs.db in qgis (using for example sqliteadmin)
- it's also possible roll you're own projection for a qgis project isn't
it? So you could make some 'template'-project in which you defined the
projection with the exact parameters of you preference.
- incorporate ALL available definitions of these multi-paramter-EPSG's
and add some interaction with the user to qgis in case there are more
definitions available for one EPSG-code. And let the user choose from
this list?
by the way: I will try to update the srs.db to match the ones used for
proj (so only the ones where there is one set of parameters for one epsg)
Richard Duivenvoorde
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