[postgis-users] create 10m buffer using input data in EPSG4326

[Jo]

I'm sorry if this is wrong, but there is another function where casting
thegeom to geography helps with that.

ST_Union(ST_Buffer(roads.the_geom::geography , 10))

I'm rather new at all this, so maybe it's bad advice.

Jo

2013/5/22 karsten <karsten at terragis.net>

> **
> Greetings, I am working on creating 10m buffers around roads:
>
> SELECT 10 AS score, ST_Difference(
>  ST_Union(ST_Buffer(roads.the_geom, 10)),
>  ST_Union(ST_Buffer(roads.the_geom, 0))
>  )
> AS the_geom
> FROM geodata.roads2012_ca roads
> GROUP BY score
>
> So far I have the roads in dd (EPSG 4326) and was wondering how I could
> pass the distances in meters into the buffer function (without necessarily
> creating a new column with projected geometries). I guess could use some
> geography data type function .. but how ?
>
> Thanks
> Karsten
>
> Karsten Vennemann
> Principal
>
> Terra GIS LTD
> 2119 Boyer Ave E
> Seattle, WA  98112
> USA
> www.terragis.net******
>
> Phone ++1 206 905 1711
> Fax      ++1 925 905 1711****
>
>
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