[OpenLayers-Users] Reprojection Example

[Christopher Schmidt]

On Tue, May 27, 2008 at 10:55:02AM -0400, Chander Ganesan wrote:
> Is there an example anywhere of taking google maps and re projecting it 
> to something else (like EPSG:4269) ?  I tried this once before and 
> couldn't get reprojection to work, and ended up just modifying my 
> MapServer WMS service to support EPSG:900913 .
> 
> If I have 6 map services that are all EPSG:4269, and want to overlay on 
> a google maps base layer, it seems like it would be better to reproject 
> the google maps layer than to reproject all 6 other layers...right?

Short answer: No.

Long answer:

The typical response to this, in my mind is: 

  http://sc.tri-bit.com/images/2/23/pony.jpg
  """
   No you can't have a pony. 
   Not Yours.
  """

Specifically:
 * Google produces Google tiles: you're not allowed to use them outside
   the Google API.
 * The Google API does not provide the ability to display the Google
   tiles in any other projection.
 * OpenLayers can't reproject images at all: there is no way to use image
   data in two different projections and have them match up in
   OpenLayers.

So, your data will need to be in the same projection as Google's to use
them together.

Regards,
-- 
Christopher Schmidt
MetaCarta