Hi Bob,

You make several good points and I hope that this moves forward.

I am less thrilled about not standardizing on WGS84.

We have agreed to use metric and other standards and I think that
data expressed using other Datum's will be largely misinterpreted.

Arthur Chapman has convinced me that it may be impossible to
get users to upload their GPS data in WGS84, but I think that
it would be best if GBIF and others converted the data in regional
Datum's into WGS84 and exposed it as WGS84.

Encouraging the use of regional Datum's instead of WGS84 will
likely lead to a number of scientific mistakes.

I am sure your are familiar with these stories, but others on the list
may not.

Math error equals loss of Mars orbiter

http://findarticles.com/p/articles/mi_m1200/is_15_156/ai_57155808/

NASA reported Sept. 30 that it had lost the $125 million Mars Climate Orbiter because the force exerted by the orbiter's thrusters remained in the system of units based on pounds and feet rather than being converted to metric.
...
In 1985, he notes, controllers calculated distance in feet rather than nautical miles and inadvertantly pointed a mirror on the space shuttle Discovery away from Earth instead of toward a laser on Hawaii's Mauna Kea.

- Pete


On Fri, Jul 17, 2009 at 9:32 PM, Bob Morris <morris.bob@gmail.com> wrote:
I would say its concern is somewhat narrower than the illustrations in
 Bricklin's http://www.w3.org/2003/01/geo/

The IETF document is a draft proposal to have "geo" be an IANA
registered URI scheme. (See http://en.wikipedia.org/wiki/URI_scheme)
whereas the w3 Bricklin stuff is an informal (as you observe)
vocabulary.

Were the IETF docment be accepted in its proposed draft form, the
expression "geo:51.47026,-2.59466" would be a URI and so in RDF/XML
one might see expressions like

    <based_near rdf:about="geo:51.47026,-2.59466"/>

for the example from the Bricklin document's element

   <based_near geo:lat="51.47026" geo:long="-2.59466"/>

All of that would support RDF semantic reasoning. For example, it
would support the ability to axiomatize something like "If point p is
in feature f, and if feature f is_near point q, then point p is_near
point q".

But in RDF you can't talk about resources that don't have a URI, so
the IETF proposal would make it possible for geographic entities to be
RDF resources. Most importantly, this would happen in such a way that
one can tell when two geographic resources are the same. For example,
the comparison definition in the IETF proposal specifies
http://www.w3.org/2005/Incubator/geo/XGR-geo-20071023/#owl that two
points are the same if their coordinates (and a few other things) are
mathematically the same. Thus, slightly oversimplified,
geo:51.47026,-2.59466 and geo:51.470260,-2.59466  (note trailing 0 in
lat) always designate the same resource,  which is something one can
only wish for in the nascent vocabulary semi-proposal, widely adopted
despite Bricklin's warning that it is not in the W3C recommendation
track.

In summary, the IETF proposal would elevate at least points to the
status of entities in their own right, as opposed to "merely"
properties of some other entity.

http://www.w3.org/2005/Incubator/geo/XGR-geo-20071023/ goes a little
farther than the Bricklin document, and identifies a need to update
that document.  It also
provides an OWL model of the main elements of GML:

 "Geo OWL provides an ontology which closely matches the GeoRSS
feature model and which utilizes the existing GeoRSS vocabulary for
geographic properties and classes. The practical consequence is that
fragments of GeoRSS XML within RSS 1.0 or Atom which conform to the
GeoRSS specification will also conform to the Geo OWL ontology
(front-matter aside). Thus, the ontology provides a compatible
extension of GeoRSS practice for use in more general RDF
contexts."--http://www.w3.org/2005/Incubator/geo/XGR-geo-20071023/#owl

So the IETF proposal should be welcome as helping uniform application
of Geo OWL, should it ever make it into the W3 recommendation process.
 Maybe Flip Dibner knows what the status of Geo OWL is.

--Bob Morris


On Fri, Jul 17, 2009 at 7:44 PM, Peter DeVries <pete.devries@gmail.com> wrote:
>
> This appears to be a more formalized version of the current w3C geo: standard.
> Which people should also be familiar with since it is widely used.
> http://www.w3.org/2003/01/geo/
>
> - Pete
>
> On Mon, Jul 6, 2009 at 1:01 PM, Bob Morris <morris.bob@gmail.com> wrote:
>>
>> TDWG should track this and consider requiring/recommending its use if it is accepted by IETF
>> Bob Morris
>>
>> ---------- Forwarded message ----------
>> From: <creed@opengeospatial.org>
>> Date: Mon, Jul 6, 2009 at 11:55 AM
>> Subject: [Tc] Geo URI proposal in draft stage in the IETF
>> To: tc@lists.opengeospatial.org
>>
>>
>> There is an internet draft that may be of interest to the OGC. I have
>> provided some review and comments but the authors are seeking additional
>> feedback. Feel free to contact the authors directly. There are GML
>> examples in the document.
>>
>> http://tools.ietf.org/id/draft-ietf-geopriv-geo-uri-01.txt
>>
>> This document specifies an Uniform Resource Identifier (URI) for
>>   geographic locations using the 'geo' scheme name.  A 'geo' URI
>>   identifies a physical location in a two- or three-dimensional
>>   coordinate reference system in a compact, simple, human-readable, and
>>   protocol independent way.  The default coordinate reference system
>>   used is WGS-84.
>>
>> Cheers
>>
>> Carl
>>
>>
>>
>>
>> _______________________________________________
>> Tc mailing list
>> Tc@lists.opengeospatial.org
>> https://lists.opengeospatial.org/mailman/listinfo/tc
>>
>> All OGC members are strongly encouraged to maintain a subscription to this list.
>>
>>
>>
>> --
>> Robert A. Morris
>> Professor of Computer Science
>> UMASS-Boston
>> ram@cs.umb.edu
>> http://bdei.cs.umb.edu/
>> http://www.cs.umb.edu/~ram
>> http://www.cs.umb.edu/~ram/calendar.html
>> phone (+1)617 287 6466
>>
>> _______________________________________________
>> tdwg-tag mailing list
>> tdwg-tag@lists.tdwg.org
>> http://lists.tdwg.org/mailman/listinfo/tdwg-tag
>>
>
>
>
> --
> ---------------------------------------------------------------
> Pete DeVries
> Department of Entomology
> University of Wisconsin - Madison
> 445 Russell Laboratories
> 1630 Linden Drive
> Madison, WI 53706
> ------------------------------------------------------------



--
Robert A. Morris
Professor of Computer Science
UMASS-Boston
ram@cs.umb.edu
http://bdei.cs.umb.edu/
http://www.cs.umb.edu/~ram
http://www.cs.umb.edu/~ram/calendar.html
phone (+1)617 287 6466



--
---------------------------------------------------------------
Pete DeVries
Department of Entomology
University of Wisconsin - Madison
445 Russell Laboratories
1630 Linden Drive
Madison, WI 53706
------------------------------------------------------------