[GeoJSON] Future plans for GeoJSON

[Sean Gillies]

Howard, I can't let you take all the blame for GeoJSON's crs. A lot of that
is my doing. And I think you're right that projection in the browser (like
http://bl.ocks.org/mbostock/4498292 or http://bl.ocks.org/mbostock/4319903)
changes the game entirely. All projecting geographic servers aren't as
necessary as they used to be and long/lat ("urn:ogc:def:crs:OGC::CRS84") is
increasingly sufficient.

Mike, I'm in favor of a single indentifier string for crs as you have above
for cases where long/lat just won't do. And I think that use of RFC 5165
URNs like "urn:ogc:def:crs:EPSG::3857" make the most sense for a GeoJSON
I-D. Perhaps a future CRSJSON could address cases not covered by OGC or
EPSG.

Other than Mike's election maps, what would break if we made crs an
optional string (defaulting to "urn:ogc:def:crs:OGC::CRS84") instead of a
JSON object?


On Fri, Apr 26, 2013 at 11:42 AM, Michael Geary <mg at mg.to> wrote:

> On Fri, Apr 26, 2013 at 9:27 AM, Howard Butler <hobu.inc at gmail.com> wrote:
>
>> As one of the primary forces behind the CRS stuff, I support the removal
>> of CRS from the GeoJSON specification. Adhoc specification of the
>> coordinate system would then be left to the implementor, and a thousand
>> turdblossoms can bloom.
>
>
> I'm one of those rare people who use the GeoJSON CRS. I built a bunch of
> election results maps for Google over the last few years, and to speed up
> the JavaScript code a bit I used Spherical Mercator coordinates since those
> convert directly to pixels with a single multiplication. So I use this CRS
> in my GeoJSON files:
>
>     "crs": {
>         "type": "name",
>         "properties": {
>             "name": "urn:ogc:def:crs:EPSG::3857"
>         }
>     }
>
> with coordinates like these:
>
>     "bbox": [ 737758, 4231185, 2061653, 5957068 ]
>
> I suppose it wouldn't make any real difference whether the crs object is
> in the standard or not, since I could just continue to use it in any case.
> Maybe if it weren't in the standard I would feel free to simplify it to:
>
>     "crs": "urn:ogc:def:crs:EPSG::3857"
>
> instead of all the extra structure it has now.
>
> So I guess I don't have an opinion one way or the other on removing the
> CRS from the standard, just wanted to mention that I'm using it.
>
> -Mike
>
>


-- 
Sean Gillies
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