[georss] multiple locations and time
Knoth, Brian D.
bknoth at mitre.org
Thu Mar 1 14:59:34 EST 2007
Mikel:
I've taken a look at the RSS source behind the temporal mapping that
you sent. As much as I agree with the philosophy of trying to use
what's available as much as possible, I just can't figure out how to
use that approach for the case I'm trying to develop. The example that
you have provided is simple enough that the single position and single
time are both related directly to the item, so they can be easily
correlated. In other words, the time says that the item is valid
between begin and end. The W3C georss then gives the position of that
item. So, ok, while the item is valid, here is where it is.
The problem I am addressing is a bit different. The item has a lifetime
(which can be expressed by xCal extensions), and within that lifetime
the item has a history, a current and a projected collection of
locations with their own time slices. I'm of the position (no pun
intended) that the location time slices must be associated directly
with the location and not loosely linked with the item.
Josh provided to me an excellent example of this using <gml:history> to
capture time with location, but it was defined within a proprietary
namespace and definition, and that's most likely the path we will have
to take. All I'm wondering is couldn't the geoRSS GML profile be
easily extended to also support this concept and provide foundational
data support for temporal mapping applications (such as what you've
done with worldkit)?
I think I've given something like this before, and I know it is not
currently supported, but it's kind of what I am looking for:
<rss ...>
<channel>
<title>Today's Flights</title>
<item>
<title>Flight 2202</title>
<description>non-stop flight from Boston to San
Jose</description>
<link>http://airlines/flightdetails/2202</link>
<xCal:dtstart>2007-03-07T11:00:00Z</xCal:dtstart>
<xCal:dtend>2007-03-07T17:00:00Z</xCal:dtstart>
<georss:where>
<gml:EnvelopeWithTimePeriod>
<gml:description>Takeoff</gml:description>
<gml:lowerCorner>42.367157
-71.010054</gml:lowerCorner>
<gml:upperCorner>42.367157
-71.010054</gml:upperCorner>
<gml:timePosition
indeterminatePosition="before">2007-03-07T11:00:00Z</gml:timePosition>
<gml:timePosition
indeterminatePosition="after">2007-03-07T11:05:00Z</gml:timePosition>
</gml:EnvelopeWithTimePeriod>
</georss:where>
<georss:where>
<gml:EnvelopeWithTimePeriod>
<gml:description>Landing</gml:description>
<gml:lowerCorner>37.361400
-121.928031</gml:lowerCorner>
<gml:upperCorner>37.361400
-121.928031</gml:upperCorner>
<gml:timePosition
indeterminatePosition="before">2007-03-07T16:45:00Z</gml:timePosition>
<gml:timePosition
indeterminatePosition="after">2007-03-07T17:15:00Z</gml:timePosition>
</gml:EnvelopeWithTimePeriod>
</georss:where>
</item>
</channel>
</rss>
I just don't see a clean way of representing this type of information
by decoupling the time periods from the locations and somehow
associating them at the <item> level.
brian
________________________________
From: Mikel Maron [mailto:mikel_maron at yahoo.com]
Sent: Wednesday, February 28, 2007 8:41 AM
To: Knoth, Brian D.; Joshua Lieberman; georss at lists.eogeo.org
Subject: Re: [georss] WAS: GeoRSS Validation Service? RETURNING
TO: multiple locations and time
Hi Brian
Don't want to belabor the issue, but I very much share your
interest in representing time and space,
and my inkling on the best way to go is leveraging RSS
time/event namespaces already in use.
Small pieces, loosely joined, of simple targeted vocabularies.
I sent some links in the thread a few
weeks back, here's another demo of using the Upcoming.org
GeoRSS/Event feeds
http://worldkit.org/upcoming/
If you 'd like to pursue this course, well, let's do it!
Mikel
----- Original Message ----
From: "Knoth, Brian D." <bknoth at mitre.org>
To: Joshua Lieberman <josh at oklieb.net>; georss at lists.eogeo.org
Sent: Wednesday, February 28, 2007 12:28:06 PM
Subject: Re: [georss] WAS: GeoRSS Validation Service? RETURNING
TO: multiple locations and time
Josh,
If by Give-and-Take, you mean that I should go off and
implement my own
extension(s) or utilize some combination of existing extensions
for
time windows and locations (while providing a loose referential
linking
between them) to support what I need, then I feel I have been
very
accommodating this. These are the suggestions that I've
received and
I'm being forced to accept them because my original
recommendation to
this mailing list of simply allowing the GML representation of
space
with time in the geoRSS profile has been discarded.
I just don't understand how an extension whose main purpose
which is to
represent location (ie, geoRSS:where) can ignore the fact that
stuff is
at a place at a specific time, usually for a period of time,
and then
at some other place for other period of time. This fact just
seems so
basic that to ignore it seriously limits the applicability of
geoRSS to
anything more than possibly just the world of blogging. GE does
a great
job of activating and deactivating things that are outside of
their
time windows when TimePeriods are specified in KML. I've heard
some
unsubstantiated rumors that GE may support geoRSS in the future
- if
that is the case, shouldn't the hooks at least be inserted into
geoRSS
now to begin preparing for that usage?
So you are absolutely correct...I can build proprietary
extensions and
mechanisms for supporting this in our RSS feeds. I have felt,
and still
strongly do feel, that the proper place for this is within a
maturing
RSS extension such as geoRSS which, hopefully for its own
adoption
sake, can provide the building blocks necessary to support
functionality required by not only the Flikrs and blogs, but
also
Enterprise RSS as well.
VR
brian
_______________________________________________
georss mailing list
georss at lists.eogeo.org
http://lists.eogeo.org/mailman/listinfo/georss
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.eogeo.org/pipermail/georss/attachments/20070301/020d2f5e/attachment.html
More information about the georss
mailing list