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"geo:" URIs

From: Alexander Mayrhofer <alexander.mayrhofer@nic.at>
Date: Mon, 27 Jun 2011 10:55:36 +0200
Message-ID: <8BC845943058D844ABFC73D2220D46650A8C7F0F@nics-mail.sbg.nic.at>
To: <public-poiwg@w3c.org>
Hello,

I'm one of the co-authors of RFC5870 - the "geo:" URI specification [1].
Since there has been some discussion about the URI scheme on this list,
i'd like to give my (obviously biased ;) view on how the POI spec could
benefit from the "geo:" URI. I understand that ISSUE-37 has been raised
specifically for the question whether or not geo: URIs should be used in
the specs, however, other raised issues might be touched by it as well:

- ISSUE-37: (obvious) 

- ISSUE-19: The "geo:" URI by definition does specify an identifier for
a point in space (optionally "diluted" by an uncertainty parameter) -
therefore, it would be a very compact, "geek-readable" and well
specified way of representing a Point. Lines and Polygons, however, are
obviously not supported. Note that lot of work went into making the
specification as precise and umanbigious as possible (read through
Section 3.4 of RFC 5870), and it was reviewed over and over by the
Geospatial community as well as the IETF (internet) community.

- ISSUE-21: A "geo:" URI always includes the specification of a
Coordinate Reference System. A lot of work in "geo:" URI went into
agreeing on a default Coordinate Reference System (WGS-84), but still
allowing for a maximum of flexibility. A Registry was created at IANA
which allows for the inclusion of more Reference Systems if needed [2].

- ISSUE-14: Having worked on the "geo:" URI specification for more than
3 years, i can only urge you to make use of other standards where you
can. If you can't use the whole standard, then refer to bits and pieces.
It saves a lot of work and pain to not re-define the semantics of
individual fields. Re-use where you can from stable standards. For
example, don't start doing your own definition of lat/lon when there's
text that has been reviewed and approved by both the geospatial as well
as the internet community (whether that's geoURI, geoJSON, PIDF-LO... it
doesn't really matter - but don't re-invent the wheel).

Hope that helps - i'm more than happy to discuss further details over
email / chat!

Alex

[1]: http://tools.ietf.org/rfc/rfc5870 
[2]:
http://www.iana.org/assignments/geo-uri-parameters/geo-uri-parameters.xm
l
Received on Monday, 27 June 2011 08:56:17 UTC

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