Re: [Geopriv] Geolocation Policy and timezone

["Brian Rosen" <br at brianrosen.net>]

I note that the original posting was about communicating the time zone of
the location, which is a relatively unchanging piece of metadata directly
associated with the location, rather than a time stamp of a measurement.  A
timestamp may or may not have a timezone, but you wouldn't use the timestamp
of a measurement to determine the timezone of the location.

Brian

> -----Original Message-----
> From: geopriv-bounces at ietf.org [mailto:geopriv-bounces at ietf.org] On Behalf
> Of creed at opengeospatial.org
> Sent: Tuesday, July 22, 2008 12:46 PM
> To: Tschofenig, Hannes (NSN - FI/Espoo)
> Cc: geopriv at ietf.org
> Subject: Re: [Geopriv] Geolocation Policy and timezone
> 
> Just thinking "out loud".
> 
> The location payload (geodetic) contained in an LO is the result of some
> measurement process. From the OGC Observations and Measurements standard
> (now also in the ISO process):
> 
> An observation is an act associated with a discrete time instant or period
> through which a number, term or other symbol is assigned to a phenomenon.
> The phenomenon is a property of an identifiable object, which is the
> feature of interest of the observation. The observation uses a procedure,
> which is often an instrument or sensor but may be a process chain, human
> observer, an algorithm, a computation or simulator. The key idea is that
> the observation result is an estimate of the value of some property of the
> feature of interest, and the other observation properties provide context
> or metadata to support evaluation, interpretation and use of the result.
> 
> The reason for providing the above process is that the time properties of
> the observation are just as important as the location of the observation
> for many applications. There may also be legal implications associated
> with not having some time metadata associated with the LO observation. Of
> course, the discussion gets interesting when one considers that there are
> multiple time aspects associated with the collection of any observation -
> sample time, result time, and so on.
> 
> The short of the long is that I would suggest that there be some time
> metadata associated with an LO. FYI, the OGC uses the following ISO
> document as the basis for defining time (as a profile of the ISO
> document).
> 
> ISO 8601:2004, Data elements and interchange formats - Information
> interchange Representation of dates and times.
> 
> Regards
> 
> Carl
> 
> 
> 
> > Recently we had a discussion on the list regarding expressing timezone
> > information in PIDF-LO. In context of that discussion I checked the
> > geolocation policy document and I noticed that we do not have a feature
> > related to timezones either. The only thing we have at the moment is the
> > ability to control the distribution of the time-offset (from RFC 5025).
> >
> > Hence, there is no condition element that allows timezones to be used.
> >
> > Should we move forward with the document without adding a timezone
> > condition element?
> >
> >
> >
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> 
> 
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