[OpenLayers-Dev] Re-projecting Layers

Bradley Mclain bradleym06 at gmail.com
Mon Jul 9 02:23:11 EDT 2007


I tried using your approach but i continue to get the incorrect projection
error.

On 7/9/07, Paul Spencer <pspencer at dmsolutions.ca> wrote:
>
> Sorry, forgot to add that to get this to work in OL, you will need to
> add SRS:'EPSG:41001' to the layer object constructor:
>
> layer = new OpenLayers.Layer.WMS( "OpenLayers WMS",
>          "http://labs.metacarta.com/wms/vmap0", {SRS:'EPSG:41001',
> layers: 'basic', 'transparent':true},
>          {isBaseLayer: false} );
>
> Cheers
> Paul
>
> On 8-Jul-07, at 9:40 PM, Bradley Mclain wrote:
>
> > This is kind of hard to explain but what I want to do is use
> > Mapserver to project my data which is in the GDA94 projection as
> > shown below:
> >
> > "# GDA94 / MGA zone 55
> > <28355> +proj=utm +zone=55 +south +ellps=GRS80
> > +towgs84=0,0,0,0,0,0,0 +units=m +no_defs  <>"
> >
> > to a projection that will be able to be properly merged with Google
> > maps (using OpenLayers) which uses a projection something like the
> > following:
> >
> > "Update 4: Agreement frrom Melita Kennedy and David Burrows that
> > Google Maps and Virtual Earth use spherical equations for the
> > Mercator projection.  The correct proj4  settings are:
> >
> > +proj=merc +latts=0 +lon0=0 +k=1.0 +x0=0 +y0=0
> > +a=6378137.0 +b=6378137.0 +units=m
> >
> > Note this is different than using the  ellipsoidal equations which
> > would be:
> >
> > +proj=merc +latts=0 +lon0=0 +k=1.0 +x0=0 +y0=0
> > +ellps=WGS84 +datum=WGS84 +units=m no_defs"
> >
> > I believe that I need to use Mapserver to do this but I have no
> > idea how to go about it. Currently my Mapserver is running fine
> > displaying the data correctly using the GDA94 projection except i
> > had to use a .vrt file to correctly align the raster image which
> > was slightly out of alignment. I have also set up and can call my
> > Mapserver as a WMS (thought having issues with the WMS Layer
> > function in OpenLayers, just displays a white screen but I believe
> > that this is to do with projections)
> >
> > My Mapserver has been compiled with GD, GDAL, GEOS, PostGIS, PHP
> > and proj4.
> >
> > In my mapfile I have defined each layer using "init=epsg:28355" as
> > well as globally defining the map using the same projection.
> >
> > This reason I am trying to do this is because currently I don't
> > think that my projection can be properly imported into OpenLayers
> > and merged with Google Maps.
> >
> > Thanks
> >
> > Brad
> >
> >
> >
> >
> > _______________________________________________
> > Dev mailing list
> > Dev at openlayers.org
> > http://openlayers.org/mailman/listinfo/dev
>
> +-----------------------------------------------------------------+
> |Paul Spencer                          pspencer at dmsolutions.ca    |
> +-----------------------------------------------------------------+
> |Chief Technology Officer                                         |
> |DM Solutions Group Inc                http://www.dmsolutions.ca/ |
> +-----------------------------------------------------------------+
>
>
>
>
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.osgeo.org/pipermail/openlayers-dev/attachments/20070709/44141023/attachment.html


More information about the Dev mailing list