[josm-dev] projection Mercator, set EPSG 3785 instead of EPSG 3857

Josh Doe josh at joshdoe.com
Mon Feb 21 03:14:28 GMT 2011


What timing. I just created a wiki page on this very subject. [1]

I've been meaning to submit a bug, but the "Mercator" projection in
JOSM is NOT EPSG:3857 as it claims, I'm not sure what EPSG or ESRI
code it corresponds to.

The definitions of EPSG:3785 and EPSG:3875 are different, but they
should be equivalent.

-Josh

[1]: http://wiki.openstreetmap.org/wiki/EPSG:3857

On Sun, Feb 20, 2011 at 8:44 PM, M∡rtin Koppenhoefer
<dieterdreist at gmail.com> wrote:
> 2011/2/21 Frederik Ramm <frederik at remote.org>:
>> Hi,
>>
>> M?rtin Koppenhoefer wrote:
>>>
>>> JOSM currently does not permit to set the Google / Bing / standard
>>> Mapnik projection if I interpret this right (there is "Mercator" which
>>> is  EPSG 3857 according to JOSM). Wouldn't it be better to set EPSG
>>> 3785 (aka 900913) as "Mercator"?
>>
>> EPSG:3857 is the "correct" number of this projection. 3785 is deprecated.
>> See
>> http://viswaug.wordpress.com/2009/04/01/gis-standards-gone-crazy-epsg-especially/
>>
>> All, including 900913, mean the same.
>
>
> I know that 3857 was introduced to replace 3785 but I get (got)
> slightly different results for 3785 and 3857 and the definitions you
> can find at EPSG are also slightly different. ( I am aware that EPSG
> says that 3785 is "not valid").
>
> cheers,
> Martin
>
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