[georss] Time and Space

Tue Feb 13 20:10:38 EST 2007

This email thread is taking up a lot of "Time and Space"

Jeff

-----Original Message-----
From: georss-bounces at lists.eogeo.org [mailto:georss-bounces at lists.eogeo.org]
On Behalf Of Ron Lake
Sent: Tuesday, February 13, 2007 8:05 PM
To: Knoth, Brian D.; Mikel Maron; georss at lists.eogeo.org
Subject: Re: [georss] Time and Space

Hi,

All I could see in your last email example was the use of a text
description. Is that what you meant?

R

-----Original Message-----
From: Knoth, Brian D. [mailto:bknoth at mitre.org] 
Sent: February 13, 2007 4:45 PM
To: Ron Lake; Mikel Maron; georss at lists.eogeo.org
Subject: RE: [georss] Time and Space

The example I had in mind I did specify in my last email.

brian 

-----Original Message-----
From: Ron Lake [mailto:rlake at galdosinc.com] 
Sent: Tuesday, February 13, 2007 5:57 PM
To: Knoth, Brian D.; Mikel Maron; georss at lists.eogeo.org
Subject: RE: [georss] Time and Space

Could you give an example of this? - I would not use description since
it is totally open ended!

R

-----Original Message-----
From: Knoth, Brian D. [mailto:bknoth at mitre.org] 
Sent: February 13, 2007 11:02 AM
To: Ron Lake; Mikel Maron; georss at lists.eogeo.org
Subject: RE: [georss] Time and Space

Ron,

I believe that "role" of a geometry can already be conveyed within the
existing GML geoRSS profile. There are description/name/metadata
elements associated with every geometry at the abstract base level. I
would think these elements could be used to pass additional information
like role to consumers. Based off my previous example, here is what I
am thinking (note: allowing multiple geometries within a where node):

		<item>
			<title>Flight 1995</title>
			<link>http://..flightdetails</link>
			<description>some desc</description>
			<guid
isPermaLink="false">id:flight-0A05000760l02yz</guid>
			<pubDate>2006-03-02T20:36:12Z</pubDate>
			<georss:where
xmlns:georss="http://www.georss.org/georss">
				<gml:Point
xmlns:gml="http://www.opengis.net/gml">

<gml:description>takeoff</gml:description>
					<gml:pos>30.8944
-124.5270</gml:pos>
				</gml:Point>			
				<gml:Envelope
xmlns:gml="http://www.opengis.net/gml">
					<gml:description>turn point
A</gml:description>
					<gml:lowerCorner>43.8944
-123.5270</gml:lowerCorner>
					<gml:upperCorner>44.3444
-122.9002</gml:upperCorner>
				</gml:Envelope>		
				<gml:EnvelopeWithTimePeriod
xmlns:gml="http://www.opengis.net/gml">

<gml:description>rendezous</gml:description>
					<gml:lowerCorner>30.8944
-107.5270</gml:lowerCorner>
					<gml:upperCorner>35.3444
-108.9002</gml:upperCorner>
					<gml:timePosition
indeterminatePosition="before">2006-03-02T21:30:00Z</gml:timePosition>
					<gml:timePosition
indeterminatePosition="after">2006-03-02T21:40:00Z</gml:timePosition>
				</gml:EnvelopeWithTimePeriod>

			</georss:where>
		</item>

Regards,
brian
________________________________

	From: Ron Lake [mailto:rlake at galdosinc.com] 
	Sent: Tuesday, February 13, 2007 11:32 AM
	To: Mikel Maron; Knoth, Brian D.; georss at lists.eogeo.org
	Subject: RE: [georss] Time and Space

	Mike:

	If you do that - allow multiple geometries inside a single
"where" property - how does anyone know what they mean?  In GML a
property (like where) is used to describe the role of the geometry -
e.g. 

	            <abc:centerLine>

	                        <gml:LineString> ... </gml:LineString>

	            </abc:centerLine>

	            <abc:position>

	                        <gml:Point>... </gml:Point>

	            </abc:Point>

	How does that work in GeoRSS?  How do you know the roles of
Point and LineString otherwise?

	Cheers

	Ron

	________________________________

		From: georss-bounces at lists.eogeo.org
[mailto:georss-bounces at lists.eogeo.org] On Behalf Of Mikel Maron
	Sent: February 12, 2007 11:50 AM
	To: Knoth, Brian D.; georss at lists.eogeo.org
	Subject: Re: [georss] Time and Space

	Brian

	There was a thread on this last month that went into the issues
.. http://lists.eogeo.org/pipermail/georss/2007-January/

	But I should've been more specific .. you can include any kind
of GML payload in GeoRSS GML, which could have multiple geometries,
	but those all would be included in a single georss:where.

	-Mikel

	----- Original Message ----
	From: "Knoth, Brian D." <bknoth at mitre.org>
	To: Mikel Maron <mikel_maron at yahoo.com>; georss at lists.eogeo.org
	Sent: Monday, February 12, 2007 7:41:39 PM
	Subject: RE: [georss] Time and Space

	Mikel,

	I'll take a look at your links in a moment, but just quickly
wanted to respond to the issue of not being able to have multiple
<georss:where> nodes under an <item>. I know that I read this
restriction somewhere else and my only question is simply why not?  I
don't know of any restriction defined in the RSS specification that
limits child elements to only a single occurrence, is there?

	thanks,

	brian

		________________________________

				From: Mikel Maron
[mailto:mikel_maron at yahoo.com] 
		Sent: Monday, February 12, 2007 2:38 PM
		To: Knoth, Brian D.; georss at lists.eogeo.org
		Subject: Re: [georss] Time and Space

		Hi Brian

		I'm very interested in incorporating time, visualizing
and acting on change. Gave a presentation outlining some thoughts on
this foss4g..

http://www.foss4g2006.org/contributionDisplay.py?contribId=161&sessionI
d=47&confId=1

		Like Raj, I think time could be seen as having wider
application than just space. I've re-used the RSS and Atom
time-oriented fields for some
		basic stuff.

		http://worldkit.org/doc/time.php

		For richer time specifications, there hasn't been
agreement on a single encoding. Upcoming.org has a bit to say on this..

http://community.upcoming.org/w/index.php/Nerdy_Questions#What_are_the_
guidelines_you_follow_when_creating_RSS_feeds.3F

		They're using xCal. There's also an old RSS 1.0 module
called Event .. http://web.resource.org/rss/1.0/modules/event/

		While writing this I just saw your followup. One thing
about your usage, you can't associate multiple georss:where elements
with a single item;
		it's a one to one relationship. 

		Best
		-Mikel

		----- Original Message ----
		From: "Knoth, Brian D." <bknoth at mitre.org>
		To: georss at lists.eogeo.org
		Sent: Monday, February 12, 2007 1:40:54 PM
		Subject: [georss] Time and Space

		Hi,

		I'm new to this mailing list, yet have been advocate of
RSS and geoRSS
		on some internal projects for a while. I do have a few
concerns with
		regard to real practical acceptance of geoRSS, yet, I
understand the
		need to try and balance simplicity and expressiveness.
As such, we are
		attempting to utilize GML geoRSS, however, we have
needed to extend the
		GML geoRSS with the ability identify time as well as
space. 

		I wanted to just send out our approach to doing this to
get comments
		from anyone else who might be interested in this on the
mailing list.
		Simply put, we have added a GML TimePeriod to each of
the geoRSS nodes
		along with the spatial representation. Here is an
example:

		<georss:where>
		    <gml:TimePeriod>
		           <gml:begin>2006-06-17T09:55:00Z</gml:begin>
		        <gml:end>2006-06-17T10:30:00Z</gml:end>
		    </gml:TimePeriod>
		    <gml:Point>
		        <gml:pos>37.65356495497155
-114.5048399056895</gml:pos>
		    </gml:Point>
		</georss:where>

		All comments would be appreciated.

		Regards,
		brian
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