[Geojson] [OSGeo-Standards] EPSG + Coordinate Ordering (Was Re: GeoJSON '1.0'?)

Paul Ramsey pramsey at cleverelephant.ca
Thu Mar 13 14:55:07 PDT 2008

I'm with Frank: say what you mean, and mean what you say.

EPSG:4326 has a particular meaning, but as long as you explicitly
over-ride that meaning in your document, at least you are saying what
*you* mean by EPSG:4326.  The WMS 1.1.0 specification did exactly

You should, as Frank suggests, go one step further and say that, "for
all geographic coordinate systems, we expect lon/lat, but that for
projected systems, we'll go with the explicit definition in the

Because this was botched (depending on your perspective, by WMS 1.0 or
by WMS 1.3) the meaning of EPSG:4326 when applied to web services is
somewhat in dispute, so just be clear about what you want in the
specification document.  Don't allow optional flags to flip the
behavior around at run-time.


On 3/13/08, Frank Warmerdam <warmerdam at pobox.com> wrote:

>  I will say there are some modest pitfalls to ignoring axis order from the
>  EPSG database.  In particular there are projected coordinate systems where
>  the axis order is important, and where the axis order in practical use
>  in the world is not "easting, northing".  So your concern is just the
>  lat/long vs. long/lat issue with geographic coordinate system then perhaps
>  you should be very specific about that.  For instance state that the axis
>  order is overridden to be "long, lat" for all *geograhic* coordinate
>  systems but that for projected or other coordinate systems EPSG axis
>  order will be honoured.

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