SPATIO-TEMPOTAL REFERENCE SYSTEMS// Geocoordinates (was: Re: Proposal to remove Preferred-Value fieldfor region YU in LTRU)

[Lang Gérard]

As we learnt from Albert Einstein, every information only makes good sense in relation with a spatio-temporal reference system. 
If we restrict our interest within a spatio-temporal sector around the orbit of the earth, we could think that it is possible to split the spatio-temporal referentiation system in two parts between a purely temporal one (like a universally recognized calendar and the Universal [Coordinated] Time [ex-Greenwich Meridian Time, GMT]) and a purely spatial one, that we call a georeferenciation system. But this is not really the case.
In fact, we essentially have two modes for georeferenciation:
-the first one, called geo-localization,  localizes points on the surface (or near the surface) of earth, by a longitude/latitude system (in dimension 2), or with addition of an altitude referenciation system (in dimension 3). This could be considered, in first approximation,  as independant of the temporal referenciation system, but only for very short time periods (think of the perspectives with planet's warming);
-the second one, called geo-codage,  codes elements of areas (in dimension 2) or volumes (in dimension 3) on the surface or near the surface of the earth, with as much levels that precision is wanted.. 
Area or volume elements can be choosed as quasi-regular geometric ones, but it is often more interesting to take as first level a territorial code like ISO 3166-1 for countries or territories, completed by a code concerning Oceans ans Seas to have a total description of the surface of the earth.
 A second possible level could be a code concerning the administrative subdivisions of ISO 3166-1 entries, as given by ISO 3166-2,  and so on (by example with something like postal codes or national geographic codes (like we have for France on "official geographical code").
It is clear that, as administrative or political frontiers are not completely stable, such codages are also not time-independant. But such geo-codages are certainly most useful for many "culture-linked" applications that are both linked with history and geography. 

Cordalement.
Gérard LANG

-----Message d'origine-----
De : ietf-languages-bounces at alvestrand.no [mailto:ietf-languages-bounces at alvestrand.no] De la part de Tex Texin
Envoyé : lundi 9 mars 2009 06:39
À : 'Doug Ewell'; ietf-languages at iana.org
Objet : RE: Geocoordinates (was: Re: Proposal to remove Preferred-Value fieldfor region YU in LTRU)

You could add a radius around the point... location lat, long, radius 100km.

A problem with this approach is that as research causes revision of the knowledge of language usage, these tags wouldn't be easily revised.
Whereas a named entity gets remapped without changing the tag.
So it might be better to choose a variant name and describe it as language or dialect used at lat, long, radius, etc. and if the understanding of the usage changes, then the definition can be revised.
tex

-----Original Message-----
From: ietf-languages-bounces at alvestrand.no [mailto:ietf-languages-bounces at alvestrand.no] On Behalf Of Doug Ewell
Sent: Sunday, March 08, 2009 9:12 PM
To: ietf-languages at iana.org
Subject: Geocoordinates (was: Re: Proposal to remove Preferred-Value field for region YU in LTRU)

Caoimhín Ó Donnaíle <caoimhin at smo dot uhi dot ac dot uk> wrote:

> In some applications, "geocoordinates" - i.e. latitude and longitude - 
> might provide a better alternative to country or regional codes.
>
> i.e. Rather than trying to decide whether a book or film or dialect 
> sample from some particular year should be tagged as "China" or 
> "Yugoslavia", for example, or trying keep an elaborate system of codes 
> for "China" or "Yugoslavia" with their changing and disputed borders 
> over time, the item could be labeled with a point in space-time: i.e.
> a date together with the geocoordinates of the town or place where it 
> originated.

I would think this might make sense as an extension, if anything (for both possible values of "if anything").  After the hurdles of writing the extension RFC and setting up the mailing list had been cleared, one might be able to write "gd-g-5705n-00553w-2009" to mean "Gaelic as spoken on Skye during 2009."

These might be perceived as "write-only" tags, providing a great deal of precision but also a great deal of difficulty in searching and matching. 
An application would have to figure out how good a match the tag above is for, say, "gd-g-5815n-00430w-xxxx" for "Gaelic as spoken in East Sutherland during the year xxxx."  (The dialects of these two areas are reportedly quite different.)  The addition of the date component would pretty much guarantee that each tag would be unique, not normally a good thing.

Another problem might be the false sense of precision that users might feel about a language variety tagged to the geographical minute or second.  This is not the world of Henry Higgins, with dialects identifiable down to the city block, but these tags might give some people that impression.  We have enough trouble with people thinking that region subtags necessarily identify a meaningful variety.

--
Doug Ewell  *  Thornton, Colorado, USA  *  RFC 4645  *  UTN #14 http://www.ewellic.org http://www1.ietf.org/html.charters/ltru-charter.html
http://www.alvestrand.no/mailman/listinfo/ietf-languages  ^ 

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