[udig-devel] Re: EPSG-ACCESS and EPS-WKT

[simone giannecchini <simboss1@xxxxxxxxx>]

We really need to fix epsg-wkt since WMS is using it heavily (DBLASBY
AM I RIGHT?). Me or alessio could that but we need a bit of help and
maybe directions.
As far as it concerns with GEOT-46 I would like to have some
directions on how to do that in order to estimate how much time that
would take because I am running out of it right now.
Please, someone let me know because this is a big issue for us right now.
Simone.

On 5/18/05, Martin Desruisseaux <martin.desruisseaux@xxxxxxxxxxxxx> wrote:
> simone giannecchini a écrit :
> > 1>Is it my impression or the Standard Mercator 1 parallel projection
> > is not yeat supported in GeoTools? I think this since I get no errors
> > or exception but nothing happens.
> 
> Mercator 1 parallel projection is supported in Geotools. If a projection
> is not supported, you should get an exception.
> 
> In the particular case of Mercator projection, one may get the illusion
> that nothing is done. This is because that at the difference of Conic or
> Stereographic projection (for example), the Cylindical Mercator
> projection keep parallels and meridians as straight lines crossing at
> right angles. The only visible difference compared to a plain
> latitude/longitude map is that parallels close to the poles are further
> apart. See:
> 
>     http://mathworld.wolfram.com/MercatorProjection.html
> 
> There is many way you can check if a projection has really be done:
> 
> - Print GridCoverage2D.getEnvelope() and check the coordinates.
> 
> - Invoke GridCoverage2D.getRenderedImage() and inspect the JAI
>   operations. You can do that graphically using the
>   org.geotools.gui.swing.ImageProperties widget (I invite you to
>   try this widget; it is of some help for debugging image processing).
> 
> 
> > 2>Are epsg-access and epsg-wkt interchangeable?
> >
> > epsg
> > [...snip...]
> >   AXIS["Geodetic latitude", NORTH, AUTHORITY["EPSG","106"]],
> >   AXIS["Geodetic longitude", EAST, AUTHORITY["EPSG","107"]],
> >
> > wkt
> > [...snip...]
> >   AXIS["Lon", EAST],
> >   AXIS["Lat", NORTH],
> 
> I checked in the EPSG database version 6.6, and the correct axis order
> is the one produced by EPSG-Access.
> 
> > This explain the problems we have been experiencing in the WMS-WCS
> > side because of the fact that we were using epsg-access and epsg-wkt
> > at the same time.
> 
> Right. So we have a choice:
> 
>    1) Either someone fix the EPSG WKT property file.
> 
> or 2) A volunter go ahead and do GEOT-46, which could be a replacement
>       for the WKT factory. See http://jira.codehaus.org/browse/GEOT-46
> 
> 
>        Martin.
>