Re: [thredds] EPSG 3857 (google maps / 900913) in TDS 4.2.5

• To: "thredds@xxxxxxxxxxxxxxxx" <thredds@xxxxxxxxxxxxxxxx>
• Subject: Re: [thredds] EPSG 3857 (google maps / 900913) in TDS 4.2.5
• From: Jon Blower <j.d.blower@xxxxxxxxxxxxx>
• Date: Thu, 31 Mar 2011 14:39:42 +0000

Hi Ivan,

Ah, I'd forgotten that the current TDS uses the espg-properties file.  The next 
version will embed the full EPSG database, which should fix this issue.  Sorry, 
I don't know what the correct parameters for 3857 should be.  I'll ask the 
Geotoolkit mailing list and get back to you if I get an answer.

Cheers, Jon


-----Original Message-----

Message: 5
Date: Thu, 31 Mar 2011 16:15:52 +0200
From: Ivan PRICE <ivan.price@xxxxxxxxxxx>
To: thredds@xxxxxxxxxxxxxxxx
Subject: Re: [thredds] EPSG 3857 (google maps / 900913) in TDS 4.2.5
Message-ID: <4D948C98.5000505@xxxxxxxxxxx>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed

Ok thanks Jon,

i tried upgrading the version of geotoolkit-bundle-referencing.jar but 
it resulted in java exceptions when i did getMap requests.

I then had a poke around in the file: epsg-wkt.jar and noticed that it 
was missing an entry for epsg 3857

3857=PROJCS["WGS 84 / Pseudo-Mercator",GEOGCS["Popular Visualisation 
CRS",DATUM["Popular_Visualisation_Datum",SPHEROID["Popular Visualisation 
Sphere",6378137,0,AUTHORITY["EPSG","7059"]],TOWGS84[0,0,0,0,0,0,0],AUTHORITY["EPSG","6055"]],
 
PRIMEM["Greenwich",0,AUTHORITY["EPSG","8901"]],UNIT["degree",0.01745329251994328,
 
AUTHORITY["EPSG","9122"]],AUTHORITY["EPSG","4055"]],UNIT["metre",1,AUTHORITY["EPSG","9001"]],
 
PROJECTION["Mercator_1SP"],PARAMETER["central_meridian",0],PARAMETER["scale_factor",1],
 
PARAMETER["false_easting",0],PARAMETER["false_northing",*-14500*],AUTHORITY["EPSG","3785"],
 
AXIS["X",EAST],AXIS["Y",NORTH]]


adding the above line to the epsg.properties file gets the WMS maps 
working, but they are shifted to the north by about 14km.  I have to add 
that bogus false northing to get them to line up properly.. ok for now 
but theres something screwy going on somewhere. maybe my definition i 
added is bad ? i got it from here:
http://spatialreference.org/ref/sr-org/6864/


cheers,

-i

• Follow-Ups:
  • Re: [thredds] EPSG 3857 (google maps / 900913) in TDS 4.2.5
    • From: Ethan Davis