[postgis-users] raster clipping

[Stephen Crawford]

Hi All,

I'm new to raster queries and i have what should be a simple operation 
but i can't figure it out.  I have a tiled raster table for the USA 
lower 48 in a Lambert Conformal Conic (LCC) projection.  I would like to 
clip this raster to the USA polygon layer, which is in epsg 4326.  Since 
I will want to repeat this process in the future, I went a head and did 
a Union and Transform of the states layer so it is now just one 
multipolygon geometry in the LCC projection.  I can't seem to write the 
query to clip the entire raster table and save it into a new table.  A 
couple of things to note:

1)The raster table has a set of tile for each day, so to just see one 
raster for the domain for one day I use:
        SELECT ST_Union(rast) WHERE observation_date = '20111201';

2) As far as I can tell ST_Clip() is not on my machine; so I was going 
to try it with ST_Intersection

Any help is greatly appreciated.

Thanks,
Steve

-- 
Stephen Crawford
Center for Environmental Informatics
The Pennsylvania State University