Re: Geographic metadata in Spatial Data on the Web Best Practices

Hello Ed

For EPSG codes, the best practice documents links to http://epsg.io in
many places. Would it be possible to replace http://epsg.io links by
http://epsg-registry.org links? The later is the only official source of
EPSG definitions, and those two sources differ in axis order and other
aspects. There is unfortunately a lot of confusion about axis order and
(to lesser extend) units of measurement of CRS defined by EPSG codes, so
I worry that having W3C referencing a site publishing non-compliant EPSG
definitions may contribute to the confusion. For example the document
has some sentences accurately describing WGS 84 as (Lat/Long), but the
link to http://epsg.io/4326 describes a (Long/Lat) system (except in
their GML definitions).

The proposed replacements are:

  * http://epsg.io/28992 ->
    http://epsg-registry.org/?display=entity&urn=urn:ogc:def:crs:EPSG::28992
  * http://epsg.io/27700 ->
    http://epsg-registry.org/?display=entity&urn=urn:ogc:def:crs:EPSG::27700
  * /etc./ for all EPSG codes (a search in the HTML source code shows 22
    occurrences).

I suggest to also replace the following sentence in chapter 8:

    Definitions of coordinate reference systems are available from the
    Open Geospatial Consortium CRS Register, Spatial Reference and
    EPSG.io (an open-source web service which simplifies discovery of
    coordinate reference systems utilized worldwide).

By

    Definitions of coordinate reference systems are available from the
    Open Geospatial Consortium CRS Register
    <http://www.opengis.net/def/crs/> and EPSG registry
    <http://epsg-registry.org/> (the official source of EPSG
    definitions). Other web services like Spatial Reference
    <http://spatialreference.org/> and EPSG.io <http://epsg.io> also
    provide definitions as used in popular software, but those
    definitions — especially the ones published in Well Known Text (WKT)
    version 1 format — sometime differ from official EPSG definitions in
    axis order and units of measurement.

Regards,

    Martin


Le 04/04/2017 à 15:16, Ed Parsons a écrit :
> Hello Neil,
>
> I am working my way through the  public comments made to the Spatial
> Data on the Web working group prior to the release of final draft of
> the Best Practice Document, current version here
> https://www.w3.org/TR/sdw-bp/
>
> Hopefully you will notice a section that deals specifically with
> approaches to making metadata about spatial data including ISO 19115
> compliant metadata more accessible - there is more work to do in this
> section before the final draft, but you very valid point about the
> value of existing metadata records has been taken onboard. 
>
> https://www.w3.org/TR/sdw-bp/#bp-metadata
>
> Would you allow me to therefore  mark this comment as closed ?
>
> Many thanks for your contribution.