google maps projection

[Ed McNierney]

John -

All you have to do is make all your polygons appear to be the wrong
size.  And get rid of the scalebars, of course; you can replace them
with rhumb lines for all the compass navigators out there <g>.

I'd suggest the following...

    proj=merc 
    lat_ts=0.0
    lon_0=-90.0 
    x_0=0.0 
    y_0=0.0 
    ellps=GRS80
    units=m 
    no_defs 

Although I haven't tested that projection myself, as I still prefer
Brazil to look larger than Greenland.  The uncommon "lat_ts" parameter
is the latitude of "true scale" - i.e. the only spot on the map that's
accurate...

For more details check the PROJ page at
http://www.remotesensing.org/geotiff/proj_list/mercator_1sp.html but
that should get you off to a good start.

	- Ed

Ed McNierney
President and Chief Mapmaker
TopoZone.com / Maps a la carte, Inc.
73 Princeton Street, Suite 305
North Chelmsford, MA  01863
ed at topozone.com
(978) 251-4242 

-----Original Message-----
From: UMN MapServer Users List [mailto:MAPSERVER-USERS at LISTS.UMN.EDU] On
Behalf Of John Hagstrand
Sent: Wednesday, October 12, 2005 2:25 PM
To: MAPSERVER-USERS at LISTS.UMN.EDU
Subject: [UMN_MAPSERVER-USERS] google maps projection

Hello,

I am using MapServer to generate maps that I then overlay on top of
Google Maps.  To get them to match up, I need to get the projections to
match.

I've been told the following:  
Google Maps uses the Mercator projection and the WGS 84 geodetic datum.
The projection standard latitude is 0, and the projection standard
longitude is -90.

How can I translate that to a MapServer Projection block?

Thanks
John

___________________
John Hagstrand
www.MapTeam.com
847 838 5371