Vishful thinking…

GIS Standards gone crazy (EPSG especially)

Posted in GIS by viswaug on April 1, 2009

A couple of weeks ago I had written about how the different axis ordering that can be defined in EPSG coordinate system standards makes the lives of any GIS software provider that wants to implement these standards a whole lot harder. Today, I came across some information that really doesn’t make any sense to me. Previously Morten had written about EPSG finally getting around to adding the web mercator to their standards with the EPSG code “3785”. But in February, EPSG decided to change the EPSG code from “3785” to “3857”. Look at the change request info in the image below. That information can be obtained at



Also, as you might have already heard, OGC had accepted KML as an OGC standard sometime last year. The KML standard includes its own method of defining styles/symbology for 2D & 3D features along with other things. But OGC in fact already had its own existing standards for defining 2D feature styles/symbology in map layers called the Styled Layer Descriptor (SLD).

Now, the OGC has two standards to define features styles in XML which really kind of makes it a double standard.

Now, from what I read, the OGC is working on combining both those standards into one. Which is going to be a tough job since there are so many overlaps between KML and other existing OGC standards.


3 Responses

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  1. Jim Sibbald said, on April 1, 2009 at 9:49 am

    This would make a good April Fool if it weren’t true!

  2. […] I ran across this today:EPSG Craziness […]

  3. […] GeoWebCache to serve up WMS layers. The coordinate system of our data is one version of the the ever-changing “Popular Visualization CRS / Mercator” projection. We needed to match up the OpenLayers […]

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