[mapserver-users] Projection EPSG code for LCC in mapserv 3.5

[Rob Atkinson]

Interesting discussion this.

IMHO - and I've been involved with both mapserver and WMS since inception, the
use of codes allows a greater degree of discovery through service registries,
and ability of client to discover how to negotiate a binding with the service.
WMS is all about interoperability after all. The lack of a better taxonomy is
a broader issue - the solution would be to have an active engagement with an
ISO process so that each country has a simple means to register its WKT
(actually the model for the projection) and get a code assigned as required.

RA

Paul Ramsey wrote:

> This dependence on the EPSG authority has got to be the worst aspect of
> the WMS spec. There are scads of useful (and widely used!) projections
> which EPSG does not have codes for. So now people are just randomly
> adding codes willy nilly. ESRI has already done so, in their
> "predefined" projections provided with ArcGIS8. They took the EPSG list,
> dropped a few projections, and then added a bunch of new ones of their
> own. I can send a proj4-style epsg file with the ESRI-added codes to
> anyone who needs it.
>
> What I do not understand is why the WMS spec does not support WKT as a
> means of defining projection information in the first place. Ironically,
> ArcIMS *does* support WKT for defining projection information.
>
> Daniel Morissette wrote:
> >
> > > Trem Stamp wrote:
> > >
> > > Does anyone know if there is an EPSG code for LCC projection
> > > information?  I seem to remember looking last time and couldn't fine
> > > one so had to use the following type of syntax:
> > >
> > >   PROJECTION
> > >   "proj=lcc"
> > >   "ellps=aust_SA"
> > >   "lat_0=-32.5"
> > >   "lon_0=147.0"
> > >   "lat_1=-29.5"
> > >   "lat_2=-36.5"
> > >   END
> > >
> > > If there is no EPSG code for this currently, does anyone know if there
> > > is likely to be in the near future?
> > >
> >
> > Trem,
> >
> > We ran into the same issue for Canadian LCC projections... there wasn't
> > any in the official list of EPSG codes.  But you can edit the
> > /usr/local/share/proj/epsg file to add your own codes... that's what we
> > ended up doing... read on...
> >
> > Cubewerx which is actively involved in all that WMS stuff had also run
> > into this issue and resolved it by defining its own extension to the
> > EPSG list for LCC and other projections useful to canadians.  They used
> > custom EPSG codes in the range 42100-42399.  We adopted the same codes
> > for our own WMS implementations and added (some of) them to our local
> > "epsg" file, so our clients and servers can exchange LCC projection with
> > other servers that also adopted Cubewerx's EPSG extension.
> >
> > Question to Frank W: Do you think the 42100-42399 custom EPSG codes
> > could be added to the official "epsg" file distributed with PROJ4?
> >
> > Now, I realize that this doesn't resolve your problem with Australian
> > projections not having an EPSG code... I think you should raise this
> > issue on the WMS-Dev list and see if a better solution to this problem
> > has been adopted.
> > (See http://www.intl-interfaces.net/mailman/listinfo/wms-dev)
> >
> > --
> > ------------------------------------------------------------
> >  Daniel Morissette               morissette at dmsolutions.ca
> >  DM Solutions Group              http://www.dmsolutions.ca/
> > ------------------------------------------------------------
> >   Don't put for tomorrow what you can do today, because if
> >       you enjoy it today you can do it again tomorrow.
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