[OSM-talk] Projection for processed_p.shp?

[Jaak Laineste (Nutiteq)]

Does it really work? I converted processed_p file with ogr2ogr into
MapInfo format (as I needed to use it with MapInfo Pro) with following
command:

ogr2ogr -f "MapInfo File" -s_srs "+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 +over" -t_srs EPSG:4326 processed_mi_wgs processed_p.shp

But the result is about 20 km north of the correct position (in
Europe, it depends on latitude, in equator error is 0). Looks like an
ellipsoid error for me.

 Actually my final target is to create similar polygons for sea (to
use as sea mask in top of raster data). Similar tiled way like
processed_p has for land. Like "invert" the data. Maybe someone
somewhere has done it already and can share the result?

/Jaak

2009/12/18 Frederik Ramm <frederik at remote.org>:
> Hi,
>
> Alexrk wrote:
>>> The projection is spherical mercator (900913), you can download a .PRJ
>>> file from the menu on
>>>
>>> http://spatialreference.org/ref/sr-org/6627/
>>
>> I've tried it in ArcMap - doesn't fit with a regular Mercator .prj file.
>
> Yes; "regular Mercator" is something other than "spherical Mercator".
>
>> I don't know, what projection this file actually is :(
>
> processed_p.shp is spherical mercator (properly EPSG:3857, formerly
> EPSG:900913, and erroneously EPSG:3857).
>
> If you don't like it, you can use ogr2ogr to reproject the shape to
> something else.
>
> Bye
> Frederik
>
> --
> Frederik Ramm  ##  eMail frederik at remote.org  ##  N49°00'09" E008°23'33"
>
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-- 
Jaak Laineste
www.nutiteq.com
Skype: jaakl3000
Mobile: +372 509 2586