[OSM-dev] Convert from Spherical Mercator to WGS-84?

[Frederik Ramm]

Hi,

Iván Sánchez Ortega wrote:
> El Sábado, 28 de Noviembre de 2009, Mike N. escribió:
>> I would like to be able to convert from Spherical Mercator coordinates
>> (used by Mapnik, I think) to WGS-84 OSM db Lat/Lon format using the Geo
>> Tools cs2cs.exe or proj.exe from the Cartographic Projections library.   I
>> am unable to figure this out from their documentation or example.
> 
> epsg:900913 and epsg:4326 are your friends. Look out for them :-)

I was unsure whether the OP was able to do coordinate conversions in 
principle and just didn't know how to access spherical mercator, or 
whether he didn't know how to use these tools at all?

Anyway, epsg:900913 is somewhat picky in choosing its friends. Sometimes 
a tender

echo "<3785> +proj=merc +a=6378137 +b=6378137 +lat_ts=0.0 +lon_0=0.0 
+x_0=0.0 +y_0=0 +k=1.0 +units=m +nadgrids=@null +no_defs <>" >> 
/usr/share/proj/epsg

helps, but I'm unsure about the equivalent of this on Windows (which the 
OP seems to be using).

Bye
Frederik

-- 
Frederik Ramm  ##  eMail frederik at remote.org  ##  N49°00'09" E008°23'33"