I am trying to calculate the average of multiple rasters stored as
raster datatype in PostGIS enabled database. The rasters are stored in three different tables (spi3, sri3, and smdi) and have
date as common column. I am trying to use ST_Union function of PostGIS, where it says we can specify
This is what I have done so far.
select st_union(SETOF[spi3_raster, sri3_raster, smdi_raster], 'MEAN') from ( select spi3.raster as spi3_raster, sri3.raster as sri3_raster, smdi.raster as smdi_raster from spi3 as spi3 join sri3 as sri3 on spi3.date = sri3.date and sri3.date = '2013-01-01' join smdi as smdi on sri3.date = smdi.date where spi3.date = '2013-01-01' ) as foo;
However, I am not getting the result as expected.