9

PostGIS comes with a table of spatial reference systems with each one being identitfied by a SRID. However, from a user's perspective, SRID is just a number and doesn't tell them much. Is there a resource that associates SRID with more descriptive names?

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    ...the srtext column of said table holds the OGC WKT representation with the standardized details of each CRS. – ThingumaBob Jan 27 at 18:14
  • Thanks! I had looked at that column initially and thought it had too much info. But upon looking at it again, I realize that I can just parse the text and extract the parts I need. I accepted your answer. – user57029 Jan 27 at 23:09
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If you want/need to have more info from within PostGIS, running something like

SELECT  srid,
        left(split_part(srtext, '"', 1), -1) AS "type",
        split_part(srtext, '"', 2) AS "name",
        split_part((regexp_split_to_array(srtext, 'UNIT\[\"'))[array_length(regexp_split_to_array(srtext, 'UNIT\[\"'), 1)], '"', 1) AS units
FROM    spatial_ref_sys
WHERE   srid IN (4326, 32632);

results in

 srid  |  type  |         name          | units  
-------+--------+-----------------------+--------
  4326 | GEOGCS | WGS 84                | degree
 32632 | PROJCS | WGS 84 / UTM zone 32N | metre

I never wanted to learn regexp logic any better than this. Obviously, you could scan the whole WKT string for anything you need to know. And improve on the above, especially the units expression...


Alternatively, query the spatial_ref_sys.srtext or spatial_ref_sys.proj4text columns to get either the whole OGC WKT representation or the proj4 definition of each SRID.

8

A good modern web resource is epsg.io

It's "modern" because it has been synchronized to recent versions of the EPSG reference database, as stated at the bottom of the web page. It's source is available on GitHub.

It's also pretty easy to use. For example, SRID=4326, here is the description web page and links to various formats:

5

I use http://spatialreference.org and http://www.epsg-registry.org.

spatialreference.org has the spatial reference information in numerous formats:

enter image description here

And EPSG has an access database you download:

enter image description here enter image description here

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    Note that spatialreference.org was last updated in 2013, and was made from an older/outdated version of the EPSG database. The webpage was abandoned, and there are no plans to update it. – Mike T Jan 27 at 22:45
  • Didn't realise that. Who owns the domain and runs the site? – Jay Cummins Jan 27 at 22:59
  • 1
    @JayCummins see about for who set it up. They are excellent folks in the opensource geospatial community, and are happy for anyone to take the keys and catch up to the modern world – Mike T Jan 27 at 23:49

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