[postgis-users] PostGIS Raster for Met Data

[Michael Akinde]

Hi,

I work with the WDB project (recently moved to github - http://github.com/wdb/wdb), a meteorological data storage built around Postgres. WDB is the backbone of  Norway's largets weather site, http://www.yr.no.

We keep a close eye on PostGIS development since it is naturally related to our type of data usage; unfortunately, we have previously not been able harness PostGIS properly for our purposes, due to the lack of Raster support. We do extraction of points (nearest or bilinear from a given point or all the points in a polygon) as well as entire rasters. Most of this implementation is code with limited functionality that we have hacked ourselves. We do use PostGIS for storage and retrieval of point data, though that part of the functionality has not really been prioritized.

PostGIS Raster is of course particularly interesting for us. Reading through the documentation, I find myself having a couple of questions, though.

- If I understand correctly, a Raster object in a table functions much like PostGIS Geometry object - including the limitation that one can only have one SRID per column. That's an issue for us, because we almost never deal with a single type of raster; we often have to deal with 10+ different data grids when doing data retrieval.

Does anyone have any experience with generating sub-tables to handle this problem? I'm particularly interested in performance, of course.

- Is there an easy (and efficient) way to run a query to get all of the coordinate points (x,y index) from within a raster that are contained in a polygon? That would be quite interesting for us if we still need to build our own solution on top of the existing functionality for performance purposes. Haven't looked at the source code yet.

Regards,

Michael A.