Some answers below:
> That said, how does the application "know" what the main elevator is and where is is location or what is really meant by Floor 4
The above are needed for navigation, but not for positioning. The first version of the draft was not intended to provide support for navigation. That capability would however be possible to add by including a link to a floorplan in a vector format, which would have objects and places tagged with the names of the INT elements (eg SVG).
> Further, what is meant by "south" and "east"?
I thought that we can safely assume that in a relatively small object like a building (relative to the dimentions of the Earth) , the axes of the Cartesian coordinate system can be assumed as being N-S and E-W (N being the true north) cardinal directions. Is this a wrong assumption?
> How does the local CRS related to the real world CRS (such as WGS 84)?
From positioning pow, it doesn't have to. If you are looking to navigate in and out of the building, then you need it. But for that to work you need to have the WGS84 coordinates of the floorplan's edges and in/out gates.
Let me know if I am terribly wrong.
- Gabor
-----Original Message-----
From: geopriv-bounces@ietf.org [mailto:geopriv-bounces@ietf.org] On Behalf Of ext Carl Reed
Sent: Monday, October 19, 2009 3:08 PM
To: Brian Rosen; Dorothy Stanley; GEOPRIV
Subject: Re: [Geopriv] Interior Location Extensions internet draft available
I also believe this draft has merit and am willing to help it progress.
That said, I am working multiple other standards activities related to indoor/outdoor navigation that have a role in a variety of domains, such as emergency response.
For example, there is a new activity just beginning titles "Open Floor Plan Display". From the activity plan:
"Conversations between industry specialists often break down in semantic frustration for many reasons. A primary reason is the lack of a common framework and strategic planning to evolve this framework. Secondly, documentation of building elements and building service performance requirements has exploded. Which parts of the living documents need to comply with long term exchange requirements for wide spread re-use?"
The work proposed envisions a next generation 9-1-1 using modern devices and open exchange languages to depict buildings and alerts in simple, interoperable formats via lightweight web services. One objective is the ability to read and pass along sensor alerts before emergencies such as fires are large enough to be observed by a by-stander phoning in. Data identities center around building addresses, standard building data representations, and alert classifications. The work will build on existing standards and practices as well as previous collaborations between the OGC, NIST, buildingSMART Alliance, GSA, and other organizations in the AEC community.
One reason I mention this work is that there are a variety of issues related to expressing location within a building and then using that information to say guide first responders.
From the draft-stanley-geopriv-int-ext-00.txt document
"within X meters of the point which is 10 meters south and 15 meters east of the main elevator on Floor 4"
I understand that perhaps the focus of the document is not on semantics.
That said, how does the application "know" what the main elevator is and where is is location or what is really meant by Floor 4. Does there need to be a statement about where the building floorplan information comes from?
Further, what is meant by "south" and "east"? In reference to the cartesian coordinate system (actually, in the engineering world, these are engineering coordinate systems), where and how is the metadata about the local CRS accessed? How does the local CRS related to the real world CRS (such as WGS 84)?
These are the types of questions that the indoor navigation community is dealing with. For example
http://portal.opengeospatial.org/files/?artifact_id=35334 is one example.
So, expressing the location of IP enabled devices should probably be in the context of the larger in-building information domain. This way, location content provided in an interior extension encoding would "fit" or fuse directly into a larger common operational picture.
Sorry for the length of this posting, but this is a really important topic.
Regards
Carl
----- Original Message -----
From: "Brian Rosen" <br@brianrosen.net>
To: "Dorothy Stanley" <dstanley1389@gmail.com>; "GEOPRIV" <geopriv@ietf.org>
Sent: Monday, October 19, 2009 3:24 PM
Subject: Re: [Geopriv] Interior Location Extensions internet draft available
> Note that this draft builds on my INT draft
> (draft-rosen-geopriv-pidf-interior-00).
>
> The authors of this draft and I have cooperated on this aspect. One of
> the
> requests that these authors have made is that we include a registry of ³N²
> names in the INT draft. While I¹m not too thrilled with that idea, I¹m
> willing to go along if the rest of the work group agrees it will be
> useful.
>
> I think this draft has a lot of merit, and I'd like to see it progress. I
> have had extended discussions with these guys. There is a significant use
> case, they have the right idea of how to solve it, and it works within the
> kinds of systems it's intended to be used with.
>
> I think the syntax proposed is very awkward, and I'd like to propose
> changes.
>
> I think the "Reference Point" this draft defines is a bad idea. I think
> that the INTs should define the reference point, and the offset should be
> relative to that.
>
> In the examples used, I think it might be expressed as:
> ...
> <HNO>123</HNO>
> <INT N="Suite">100</INT>
> <INT N="Door">Front</INT>
> And then something like
> <POINT_OFFSET>
> <X>100</X>
> <Y>200</Y>
> </POINT_OFFSET>
>
> At this time, however, I think the syntax issues are not important and the
> basic idea is.
>
> Brian
>
>
>
> On 10/19/09 3:51 PM, "Dorothy Stanley" <dstanley1389@gmail.com> wrote:
>
>> All,
>>
>> An internet draft for Interior Location Extensions is now posted, see
>> http://www.ietf.org/id/draft-stanley-geopriv-int-ext-00.txt .
>>
>> This document supports the request for Location by reference
>> extensions in 11-09-0718-01-000v-liaison-request-to-ietf-geopriv.doc,
>> (available at http://trac.tools.ietf.org/wg/geopriv/trac/wiki ).
>> Extensions to existing Civic definitions include reference point, offset
>> and
>> shape
>> components.
>>
>> I've asked Alissa & Richard for time to present this in Hiroshima.
>>
>> Thanks,
>>
>> Dorothy Stanley
>>
>>
>> ------------------------
>> Dorothy Stanley
>> Aruba Networks
>> dstanley@arubanetworks.com <mailto:dstanley@arubanetworks.com>
>> 630-363-1389
>>
>>
>>
>>
>>
>> _______________________________________________
>> Geopriv mailing list
>> Geopriv@ietf.org
>> https://www.ietf.org/mailman/listinfo/geopriv
>
>
> _______________________________________________
> Geopriv mailing list
> Geopriv@ietf.org
> https://www.ietf.org/mailman/listinfo/geopriv
>
_______________________________________________
Geopriv mailing list
Geopriv@ietf.org
https://www.ietf.org/mailman/listinfo/geopriv
_______________________________________________
Geopriv mailing list
Geopriv@ietf.org
https://www.ietf.org/mailman/listinfo/geopriv
