simple 3D geocode for AR

[Mike Liebhold]

A friend wrote me with a request for clarification on a topic we've
discussed many times here,  but every time we've approached a consensus
the answer seems elusive.

Many devleopers are starting to create applications for iPhones and
Android phones to view location specific data  through the viewfinder
using the -imprecise- capabilities of the built in gps and compass and
applications platforms like Layar.

The question:

What is the -simplest- way to geocode a geoannotation in 3D using
geoRSS/Atom, geojson, KML ....?

(Is there a practical reason why WGS '84 shouldn't be implicit, and a
CRS  lookup NOT be required?)


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[Carl Reed]

Mike -

Interesting questions.

What is simple? There is an interesting quote by the mathematician
Whitehead, "Seek simplicity but distrust it."

Interesting quote :-) especially given recent stories about folks using GPS
and getting themselves into interesting situations with legal and liability
issues.

Anyway, I will get off of my soapbox.

As to WGS 84 being explicit, as long as the supporting documentation is VERY
clear about what is meant by WGS-84, e.g. 2d, 3d, projected, geodetic,
geographic. I would suggest an explicit reference to the EPSG registry for
code 4979 (3d geographic). I would also suggest checking out some IETF
standards that deal with "simple" expressions for locations (ones I am
familiar with), such as for DHCP ([RFC 3825] "Dynamic Host Configuration
Protocol Option for Coordinate-based Location Configuration Information" and
internet draft "A Uniform Resource Identifier for Geographic Locations
('geo' URI)"

One of the issues we have been dealing with in all of these location
protocols and encodings in the IETF, NENA and the OGC is the issue
uncertainty. Without some expression of uncertainty, then how does one
access the quality/value/appropriate usage for the coordinate(s)? And of
course then there are the related legal and liability issues.

Hence, the above quote!

Regards

Carl



----- Original Message -----
From: "Mike Liebhold" <mnl@...>
To: <geowanking@...>; <georss@...>;
<geojson@...>; "Gene Becker" <gbecker8888@...>
Sent: Thursday, August 27, 2009 5:35 PM
Subject: [georss] simple 3D geocode for AR

>A friend wrote me with a request for clarification on a topic we've
> discussed many times here,  but every time we've approached a consensus
> the answer seems elusive.
>
> Many devleopers are starting to create applications for iPhones and
> Android phones to view location specific data  through the viewfinder
> using the -imprecise- capabilities of the built in gps and compass and
> applications platforms like Layar.
>
> The question:
>
> What is the -simplest- way to geocode a geoannotation in 3D using
> geoRSS/Atom, geojson, KML ....?
>
> (Is there a practical reason why WGS '84 shouldn't be implicit, and a
> CRS  lookup NOT be required?)
>
>
> _______________________________________________
> georss mailing list
> georss@...
> http://lists.eogeo.org/mailman/listinfo/georss 

_______________________________________________
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georss@...
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[Dan Brickley-2]

On Fri, Aug 28, 2009 at 2:01 AM, David Colleen<dcolleen@...> wrote:
> Hi Mike
>
> This is easy in X3D (web3d.org). Geo-referencing support is native to X3D
> and one of the reasons that it is the foundation of CityGML.
>
> BTW... Fraunhofer should have their iPhone X3D viewer out shortly. I would
> expect Java based Android clients out soon as well.


Is there anything for ordinary desktop users yet (win/OSX/linux, ...)
? I used to have a bunch of VRML viewers on my desktop in the mid
'90s, yet whenever I look around lately for the state of play with
X3D, it feels like time has somehow run backwards. Am I missing
something obvious (besides patience?) or we have a problem here? When
do we get the 3d homepages that were long promised us? :)

cheers,

Dan
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[joshli]

a 2-D not 3-D WGS84 is the default for GeoRSS, but there is also an  
elev attribute whose default is number of meters above geoid (e.g. GPS  
elevation). For an imprecise geoannotation, height relative to terrain  
would probably be more useful (georss:floor but that is in units of  
building floors). A perspective might also be important (not currently  
defined in GeoRSS) if the geoannotation has been applied to one side  
of a vertical feature.


On Aug 27, 2009, at 7:35 PM, Mike Liebhold wrote:

> A friend wrote me with a request for clarification on a topic we've  
> discussed many times here,  but every time we've approached a  
> consensus the answer seems elusive.
>
> Many devleopers are starting to create applications for iPhones and  
> Android phones to view location specific data  through the  
> viewfinder using the -imprecise- capabilities of the built in gps  
> and compass and applications platforms like Layar.
>
> The question:
>
> What is the -simplest- way to geocode a geoannotation in 3D using  
> geoRSS/Atom, geojson, KML ....?
>
> (Is there a practical reason why WGS '84 shouldn't be implicit, and  
> a CRS  lookup NOT be required?)
>
>
>
> _______________________________________________
> Geowanking mailing list
> Geowanking@...
> http://geowanking.org/mailman/listinfo/geowanking_geowanking.org

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[Carl Reed]

All -

Another document that is in the IETF standards track is HTTP Enabled
Location Delivery (HELD) draft-ietf-geopriv-http-location-delivery-15.txt .
The document describes a Layer 7 Location Configuration Protocol (L7 LCP)
that  is used for retrieving location information from a server within an
access network. Again, this is not a "simple" or lightweight. However, there
are elements that may be useful in discussions related to what Mike has
asked. I should also note that HELD is gaining significant implementation
acceptance in the internet infrastructure community and will be a mandated
standard for use in the Next Generation 9-1-1 deployment.

Regards

Carl


----- Original Message -----
From: "Mike Liebhold" <mnl@...>
To: <geowanking@...>; <georss@...>;
<geojson@...>; "Gene Becker" <gbecker8888@...>
Sent: Thursday, August 27, 2009 5:35 PM
Subject: [georss] simple 3D geocode for AR

>A friend wrote me with a request for clarification on a topic we've
> discussed many times here,  but every time we've approached a consensus
> the answer seems elusive.
>
> Many devleopers are starting to create applications for iPhones and
> Android phones to view location specific data  through the viewfinder
> using the -imprecise- capabilities of the built in gps and compass and
> applications platforms like Layar.
>
> The question:
>
> What is the -simplest- way to geocode a geoannotation in 3D using
> geoRSS/Atom, geojson, KML ....?
>
> (Is there a practical reason why WGS '84 shouldn't be implicit, and a
> CRS  lookup NOT be required?)
>
>
> _______________________________________________
> georss mailing list
> georss@...
> http://lists.eogeo.org/mailman/listinfo/georss 

_______________________________________________
georss mailing list
georss@...
http://lists.eogeo.org/mailman/listinfo/georss

[Andrew Turner-8]

Simplest?

Just include a 3rd coordinate in GeoRSS-Simple point or GeoJSON point.

No, this is not explicitly valid. But you see where that discussion
gets us. Long windy roads of elusive semantic talk (arguably necessary
in the lon term, but not simple or useable *now*, which is when people
are building these tools).

If we lose interest without achieving a near term concensus,
developers will just do arbitrary, different solutions. Give them a
simple answer now, even if it makes your strict-validation-only-skin
crawl just a little bit. :)

So I say just do it, and we'll catch up with documenting it as uses
emerge.

Also, KML already supports 3D points.

Andrew



(via mobile)

On Aug 27, 2009, at 4:35 PM, Mike Liebhold <mnl@...> wrote:

> A friend wrote me with a request for clarification on a topic we've
> discussed many times here,  but every time we've approached a
> consensus the answer seems elusive.
>
> Many devleopers are starting to create applications for iPhones and
> Android phones to view location specific data  through the
> viewfinder using the -imprecise- capabilities of the built in gps
> and compass and applications platforms like Layar.
>
> The question:
>
> What is the -simplest- way to geocode a geoannotation in 3D using
> geoRSS/Atom, geojson, KML ....?
>
> (Is there a practical reason why WGS '84 shouldn't be implicit, and
> a CRS  lookup NOT be required?)
>
>
> _______________________________________________
> Geojson mailing list
> Geojson@...
> http://lists.geojson.org/listinfo.cgi/geojson-geojson.org

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georss@...
http://lists.eogeo.org/mailman/listinfo/georss

[Ron Lake]

If all you want is a Point then use one of the existing encodings e.g.
GML, geoRSS GML, KML etc - they are all more or less the same with
respect to simplicity - but I would add a URI attribute to identify the
CRS, which for now can be restricted to one CRS.

        <Point id = 'P1" CRS = "http://www.blah.bla/standardCRS.xml">
                <coordinates>100 200</coordinates>
        </Point>

No one needs to look up the CRS, but the hook is there for different CRS
in the future.  Using WGS84 (2D, 3D geographic) for points local to a
picture taker seems pretty crazy - but for the location of the picture
taker it seems fine.  People will discover what they need and populate
the needed CRS in the future.

R

-----Original Message-----
From: georss-bounces@...
[mailto:georss-bounces@...] On Behalf Of Andrew Turner
Sent: August 28, 2009 9:57 AM
To: geowanking@...; GeoRSS; geojson
Subject: Re: [georss] [Geojson] simple 3D geocode for AR

Simplest?

Just include a 3rd coordinate in GeoRSS-Simple point or GeoJSON point.

No, this is not explicitly valid. But you see where that discussion
gets us. Long windy roads of elusive semantic talk (arguably necessary
in the lon term, but not simple or useable *now*, which is when people
are building these tools).

If we lose interest without achieving a near term concensus,
developers will just do arbitrary, different solutions. Give them a
simple answer now, even if it makes your strict-validation-only-skin
crawl just a little bit. :)

So I say just do it, and we'll catch up with documenting it as uses
emerge.

Also, KML already supports 3D points.

Andrew



(via mobile)

On Aug 27, 2009, at 4:35 PM, Mike Liebhold <mnl@...> wrote:

> A friend wrote me with a request for clarification on a topic we've
> discussed many times here,  but every time we've approached a
> consensus the answer seems elusive.
>
> Many devleopers are starting to create applications for iPhones and
> Android phones to view location specific data  through the
> viewfinder using the -imprecise- capabilities of the built in gps
> and compass and applications platforms like Layar.
>
> The question:
>
> What is the -simplest- way to geocode a geoannotation in 3D using
> geoRSS/Atom, geojson, KML ....?
>
> (Is there a practical reason why WGS '84 shouldn't be implicit, and
> a CRS  lookup NOT be required?)
>
>
> _______________________________________________
> Geojson mailing list
> Geojson@...
> http://lists.geojson.org/listinfo.cgi/geojson-geojson.org

_______________________________________________
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http://lists.eogeo.org/mailman/listinfo/georss
_______________________________________________
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[Ron Lake]

Sorry my example should have been

        <Point id = "P1"  CRS = "http://www.blah.bla/standardCRS.xml">
                <coordinates>100 200  150</coordinates>
        </Point>

But the argument is the same.  Similar encodings can be made in JSON
etc.

R

-----Original Message-----
From: georss-bounces@...
[mailto:georss-bounces@...] On Behalf Of Andrew Turner
Sent: August 28, 2009 9:57 AM
To: geowanking@...; GeoRSS; geojson
Subject: Re: [georss] [Geojson] simple 3D geocode for AR

Simplest?

Just include a 3rd coordinate in GeoRSS-Simple point or GeoJSON point.

No, this is not explicitly valid. But you see where that discussion
gets us. Long windy roads of elusive semantic talk (arguably necessary
in the lon term, but not simple or useable *now*, which is when people
are building these tools).

If we lose interest without achieving a near term concensus,
developers will just do arbitrary, different solutions. Give them a
simple answer now, even if it makes your strict-validation-only-skin
crawl just a little bit. :)

So I say just do it, and we'll catch up with documenting it as uses
emerge.

Also, KML already supports 3D points.

Andrew



(via mobile)

On Aug 27, 2009, at 4:35 PM, Mike Liebhold <mnl@...> wrote:

> A friend wrote me with a request for clarification on a topic we've
> discussed many times here,  but every time we've approached a
> consensus the answer seems elusive.
>
> Many devleopers are starting to create applications for iPhones and
> Android phones to view location specific data  through the
> viewfinder using the -imprecise- capabilities of the built in gps
> and compass and applications platforms like Layar.
>
> The question:
>
> What is the -simplest- way to geocode a geoannotation in 3D using
> geoRSS/Atom, geojson, KML ....?
>
> (Is there a practical reason why WGS '84 shouldn't be implicit, and
> a CRS  lookup NOT be required?)
>
>
> _______________________________________________
> Geojson mailing list
> Geojson@...
> http://lists.geojson.org/listinfo.cgi/geojson-geojson.org

_______________________________________________
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[crschmidt]

On Fri, Aug 28, 2009 at 09:56:54AM -0700, Andrew Turner wrote:
> Simplest?
>
> Just include a 3rd coordinate in GeoRSS-Simple point or GeoJSON point.
>
> No, this is not explicitly valid.

This is explicitly valid in GeoJSON:

A position is represented by an array of numbers. There must be at least
two elements, and may be more. The order of elements must follow x, y, z
order (easting, northing, altitude for coordinates in a projected
coordinate reference system, or longitude, latitude, altitude for
coordinates in a geographic coordinate reference system). Any number of
additional elements are allowed -- interpretation and meaning of
additional elements is beyond the scope of this specification.

 -- http://geojson.org/geojson-spec.html#positions

> But you see where that discussion
> gets us. Long windy roads of elusive semantic talk (arguably necessary
> in the lon term, but not simple or useable *now*, which is when people
> are building these tools).
>
> If we lose interest without achieving a near term concensus,
> developers will just do arbitrary, different solutions. Give them a
> simple answer now, even if it makes your strict-validation-only-skin
> crawl just a little bit. :)
>
> So I say just do it, and we'll catch up with documenting it as uses
> emerge.
>
> Also, KML already supports 3D points.
>
> Andrew
>
>
>
> (via mobile)
>
> On Aug 27, 2009, at 4:35 PM, Mike Liebhold <mnl@...> wrote:
>
> > A friend wrote me with a request for clarification on a topic we've
> > discussed many times here,  but every time we've approached a
> > consensus the answer seems elusive.
> >
> > Many devleopers are starting to create applications for iPhones and
> > Android phones to view location specific data  through the
> > viewfinder using the -imprecise- capabilities of the built in gps
> > and compass and applications platforms like Layar.
> >
> > The question:
> >
> > What is the -simplest- way to geocode a geoannotation in 3D using
> > geoRSS/Atom, geojson, KML ....?
> >
> > (Is there a practical reason why WGS '84 shouldn't be implicit, and
> > a CRS  lookup NOT be required?)
> >
> >
> > _______________________________________________
> > Geojson mailing list
> > Geojson@...
> > http://lists.geojson.org/listinfo.cgi/geojson-geojson.org
> _______________________________________________
> Geojson mailing list
> Geojson@...
> http://lists.geojson.org/listinfo.cgi/geojson-geojson.org

--
Christopher Schmidt
MetaCarta
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[joshli]

In both GeoRSS GML and GeoJSON, some explicit CRS needs to be  
specified to use 3-coordinate locations. The simplest one for GeoRSS  
seems to be epsg:4979 ( urn:ogc:def:crs:EPSG:4979 ). It would need a  
slight modification to support the GeoJSON long-lat encoding.  
Otherwise use GeoRSS Simple and the elev property.

e.g.

<georss:elev>346</georss:elev>
<georss:point>42.3234 -173.234134</georss:point>

Well-known text description of 4979 (http://spatialreference.org/ref/epsg/4979/ 
)
GEOGCS["WGS 84", DATUM["World Geodetic System 1984", SPHEROID["WGS 84",
6378137.0,298.257223563, AUTHORITY["EPSG","7030"]],          
AUTHORITY["EPSG","6326"]], PRIMEM["Greenwich",0.0,  
AUTHORITY["EPSG","8901"]], UNIT["degree",0.017453292519943295],  
AXIS["Geodetic latitude",NORTH], AXIS["Geodetic longitude",EAST],  
AXIS["Ellipsoidal height",UP], AUTHORITY["EPSG","4979"]]

Josh

On Aug 28, 2009, at 1:05 PM, Ron Lake wrote:

> Sorry my example should have been
>
> <Point id = "P1"  CRS = "http://www.blah.bla/standardCRS.xml">
> <coordinates>100 200  150</coordinates>
> </Point>
>
> But the argument is the same.  Similar encodings can be made in JSON
> etc.
>
> R
>
> -----Original Message-----
> From: georss-bounces@...
> [mailto:georss-bounces@...] On Behalf Of Andrew Turner
> Sent: August 28, 2009 9:57 AM
> To: geowanking@...; GeoRSS; geojson
> Subject: Re: [georss] [Geojson] simple 3D geocode for AR
>
> Simplest?
>
> Just include a 3rd coordinate in GeoRSS-Simple point or GeoJSON point.
>
> No, this is not explicitly valid. But you see where that discussion
> gets us. Long windy roads of elusive semantic talk (arguably necessary
> in the lon term, but not simple or useable *now*, which is when people
> are building these tools).
>
> If we lose interest without achieving a near term concensus,
> developers will just do arbitrary, different solutions. Give them a
> simple answer now, even if it makes your strict-validation-only-skin
> crawl just a little bit. :)
>
> So I say just do it, and we'll catch up with documenting it as uses
> emerge.
>
> Also, KML already supports 3D points.
>
> Andrew
>
>
>
> (via mobile)
>
> On Aug 27, 2009, at 4:35 PM, Mike Liebhold <mnl@...> wrote:
>
>> A friend wrote me with a request for clarification on a topic we've
>> discussed many times here,  but every time we've approached a
>> consensus the answer seems elusive.
>>
>> Many devleopers are starting to create applications for iPhones and
>> Android phones to view location specific data  through the
>> viewfinder using the -imprecise- capabilities of the built in gps
>> and compass and applications platforms like Layar.
>>
>> The question:
>>
>> What is the -simplest- way to geocode a geoannotation in 3D using
>> geoRSS/Atom, geojson, KML ....?
>>
>> (Is there a practical reason why WGS '84 shouldn't be implicit, and
>> a CRS  lookup NOT be required?)
>>
>>
>> _______________________________________________
>> Geojson mailing list
>> Geojson@...
>> http://lists.geojson.org/listinfo.cgi/geojson-geojson.org
> _______________________________________________
> georss mailing list
> georss@...
> http://lists.eogeo.org/mailman/listinfo/georss
> _______________________________________________
> georss mailing list
> georss@...
> http://lists.eogeo.org/mailman/listinfo/georss

_______________________________________________
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[Ron Lake]

I suspect that in augmented reality applications you are going to want
to express the location of the camera (determined by GPS) and the
location of things in the field of view relative to the camera.  The use
of geographic coordinates for the first makes sense.  The use of
geographic coordinates for the second likely does not.

R

-----Original Message-----
From: georss-bounces@...
[mailto:georss-bounces@...] On Behalf Of Joshua Lieberman
Sent: August 28, 2009 11:03 AM
To: geowanking@...
Cc: geojson; GeoRSS
Subject: Re: [georss] [Geojson] simple 3D geocode for AR

In both GeoRSS GML and GeoJSON, some explicit CRS needs to be  
specified to use 3-coordinate locations. The simplest one for GeoRSS  
seems to be epsg:4979 ( urn:ogc:def:crs:EPSG:4979 ). It would need a  
slight modification to support the GeoJSON long-lat encoding.  
Otherwise use GeoRSS Simple and the elev property.

e.g.

<georss:elev>346</georss:elev>
<georss:point>42.3234 -173.234134</georss:point>

Well-known text description of 4979
(http://spatialreference.org/ref/epsg/4979/ 
)
GEOGCS["WGS 84", DATUM["World Geodetic System 1984", SPHEROID["WGS 84",
6378137.0,298.257223563, AUTHORITY["EPSG","7030"]],          
AUTHORITY["EPSG","6326"]], PRIMEM["Greenwich",0.0,  
AUTHORITY["EPSG","8901"]], UNIT["degree",0.017453292519943295],  
AXIS["Geodetic latitude",NORTH], AXIS["Geodetic longitude",EAST],  
AXIS["Ellipsoidal height",UP], AUTHORITY["EPSG","4979"]]

Josh

On Aug 28, 2009, at 1:05 PM, Ron Lake wrote:

> Sorry my example should have been
>
> <Point id = "P1"  CRS = "http://www.blah.bla/standardCRS.xml">
> <coordinates>100 200  150</coordinates>
> </Point>
>
> But the argument is the same.  Similar encodings can be made in JSON
> etc.
>
> R
>
> -----Original Message-----
> From: georss-bounces@...
> [mailto:georss-bounces@...] On Behalf Of Andrew Turner
> Sent: August 28, 2009 9:57 AM
> To: geowanking@...; GeoRSS; geojson
> Subject: Re: [georss] [Geojson] simple 3D geocode for AR
>
> Simplest?
>
> Just include a 3rd coordinate in GeoRSS-Simple point or GeoJSON point.
>
> No, this is not explicitly valid. But you see where that discussion
> gets us. Long windy roads of elusive semantic talk (arguably necessary
> in the lon term, but not simple or useable *now*, which is when people
> are building these tools).
>
> If we lose interest without achieving a near term concensus,
> developers will just do arbitrary, different solutions. Give them a
> simple answer now, even if it makes your strict-validation-only-skin
> crawl just a little bit. :)
>
> So I say just do it, and we'll catch up with documenting it as uses
> emerge.
>
> Also, KML already supports 3D points.
>
> Andrew
>
>
>
> (via mobile)
>
> On Aug 27, 2009, at 4:35 PM, Mike Liebhold <mnl@...> wrote:
>
>> A friend wrote me with a request for clarification on a topic we've
>> discussed many times here,  but every time we've approached a
>> consensus the answer seems elusive.
>>
>> Many devleopers are starting to create applications for iPhones and
>> Android phones to view location specific data  through the
>> viewfinder using the -imprecise- capabilities of the built in gps
>> and compass and applications platforms like Layar.
>>
>> The question:
>>
>> What is the -simplest- way to geocode a geoannotation in 3D using
>> geoRSS/Atom, geojson, KML ....?
>>
>> (Is there a practical reason why WGS '84 shouldn't be implicit, and
>> a CRS  lookup NOT be required?)
>>
>>
>> _______________________________________________
>> Geojson mailing list
>> Geojson@...
>> http://lists.geojson.org/listinfo.cgi/geojson-geojson.org
> _______________________________________________
> georss mailing list
> georss@...
> http://lists.eogeo.org/mailman/listinfo/georss
> _______________________________________________
> georss mailing list
> georss@...
> http://lists.eogeo.org/mailman/listinfo/georss

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[Mike Liebhold]

Ron Lake wrote:
> The use of geographic coordinates for [location of things in the field of view relative to the camera]  likely does not. [ make sense]
>  

Ron,

This is really counter intuitive, Can you explain what you mean?

- Mike

>
> -----Original Message-----
> From: georss-bounces@...
> [mailto:georss-bounces@...] On Behalf Of Joshua Lieberman
> Sent: August 28, 2009 11:03 AM
> To: geowanking@...
> Cc: geojson; GeoRSS
> Subject: Re: [georss] [Geojson] simple 3D geocode for AR
>
> In both GeoRSS GML and GeoJSON, some explicit CRS needs to be  
> specified to use 3-coordinate locations. The simplest one for GeoRSS  
> seems to be epsg:4979 ( urn:ogc:def:crs:EPSG:4979 ). It would need a  
> slight modification to support the GeoJSON long-lat encoding.  
> Otherwise use GeoRSS Simple and the elev property.
>
> e.g.
>
> <georss:elev>346</georss:elev>
> <georss:point>42.3234 -173.234134</georss:point>
>
> Well-known text description of 4979
> (http://spatialreference.org/ref/epsg/4979/ 
> )
> GEOGCS["WGS 84", DATUM["World Geodetic System 1984", SPHEROID["WGS 84",
> 6378137.0,298.257223563, AUTHORITY["EPSG","7030"]],          
> AUTHORITY["EPSG","6326"]], PRIMEM["Greenwich",0.0,  
> AUTHORITY["EPSG","8901"]], UNIT["degree",0.017453292519943295],  
> AXIS["Geodetic latitude",NORTH], AXIS["Geodetic longitude",EAST],  
> AXIS["Ellipsoidal height",UP], AUTHORITY["EPSG","4979"]]
>
> Josh
>
> On Aug 28, 2009, at 1:05 PM, Ron Lake wrote:
>
>  
>> Sorry my example should have been
>>
>> <Point id = "P1"  CRS = "http://www.blah.bla/standardCRS.xml">
>> <coordinates>100 200  150</coordinates>
>> </Point>
>>
>> But the argument is the same.  Similar encodings can be made in JSON
>> etc.
>>
>> R
>>
>> -----Original Message-----
>> From: georss-bounces@...
>> [mailto:georss-bounces@...] On Behalf Of Andrew Turner
>> Sent: August 28, 2009 9:57 AM
>> To: geowanking@...; GeoRSS; geojson
>> Subject: Re: [georss] [Geojson] simple 3D geocode for AR
>>
>> Simplest?
>>
>> Just include a 3rd coordinate in GeoRSS-Simple point or GeoJSON point.
>>
>> No, this is not explicitly valid. But you see where that discussion
>> gets us. Long windy roads of elusive semantic talk (arguably necessary
>> in the lon term, but not simple or useable *now*, which is when people
>> are building these tools).
>>
>> If we lose interest without achieving a near term concensus,
>> developers will just do arbitrary, different solutions. Give them a
>> simple answer now, even if it makes your strict-validation-only-skin
>> crawl just a little bit. :)
>>
>> So I say just do it, and we'll catch up with documenting it as uses
>> emerge.
>>
>> Also, KML already supports 3D points.
>>
>> Andrew
>>
>>
>>
>> (via mobile)
>>
>> On Aug 27, 2009, at 4:35 PM, Mike Liebhold <mnl@...> wrote:
>>
>>    
>>> A friend wrote me with a request for clarification on a topic we've
>>> discussed many times here,  but every time we've approached a
>>> consensus the answer seems elusive.
>>>
>>> Many devleopers are starting to create applications for iPhones and
>>> Android phones to view location specific data  through the
>>> viewfinder using the -imprecise- capabilities of the built in gps
>>> and compass and applications platforms like Layar.
>>>
>>> The question:
>>>
>>> What is the -simplest- way to geocode a geoannotation in 3D using
>>> geoRSS/Atom, geojson, KML ....?
>>>
>>> (Is there a practical reason why WGS '84 shouldn't be implicit, and
>>> a CRS  lookup NOT be required?)
>>>
>>>
>>> _______________________________________________
>>> Geojson mailing list
>>> Geojson@...
>>> http://lists.geojson.org/listinfo.cgi/geojson-geojson.org
>>>      
>> _______________________________________________
>> georss mailing list
>> georss@...
>> http://lists.eogeo.org/mailman/listinfo/georss
>> _______________________________________________
>> georss mailing list
>> georss@...
>> http://lists.eogeo.org/mailman/listinfo/georss
>>    
>
> _______________________________________________
> georss mailing list
> georss@...
> http://lists.eogeo.org/mailman/listinfo/georss
> _______________________________________________
> georss mailing list
> georss@...
> http://lists.eogeo.org/mailman/listinfo/georss
>
>
>  

_______________________________________________
georss mailing list
georss@...
http://lists.eogeo.org/mailman/listinfo/georss

[Ron Lake]

Sure.

Location of the camera - where in the world are you.  For this
geographic coordinates - e.g. (lat,lon) makes sense.

Now in the field of view of the camera, I can see things.  I am
interested in their shape, location etc. relative to the camera or
relative to me, the holder of the camera.  The most logical coordinate
system for locating such items is a rectilinear coordinate system (x-y-z
frame) centered (origin) at the focal point of the camera.  

Cheers

Ron


-----Original Message-----
From: Mike Liebhold [mailto:mnl@...]
Sent: August 28, 2009 2:05 PM
To: Ron Lake
Cc: Joshua Lieberman; geowanking@...; geojson; GeoRSS
Subject: Re: [georss] [Geojson] simple 3D geocode for AR

Ron Lake wrote:
> The use of geographic coordinates for [location of things in the field
of view relative to the camera]  likely does not. [ make sense]
>  

Ron,

This is really counter intuitive, Can you explain what you mean?

- Mike

>
> -----Original Message-----
> From: georss-bounces@...
> [mailto:georss-bounces@...] On Behalf Of Joshua Lieberman
> Sent: August 28, 2009 11:03 AM
> To: geowanking@...
> Cc: geojson; GeoRSS
> Subject: Re: [georss] [Geojson] simple 3D geocode for AR
>
> In both GeoRSS GML and GeoJSON, some explicit CRS needs to be  
> specified to use 3-coordinate locations. The simplest one for GeoRSS  
> seems to be epsg:4979 ( urn:ogc:def:crs:EPSG:4979 ). It would need a  
> slight modification to support the GeoJSON long-lat encoding.  
> Otherwise use GeoRSS Simple and the elev property.
>
> e.g.
>
> <georss:elev>346</georss:elev>
> <georss:point>42.3234 -173.234134</georss:point>
>
> Well-known text description of 4979
> (http://spatialreference.org/ref/epsg/4979/ 
> )
> GEOGCS["WGS 84", DATUM["World Geodetic System 1984", SPHEROID["WGS

84",

> 6378137.0,298.257223563, AUTHORITY["EPSG","7030"]],          
> AUTHORITY["EPSG","6326"]], PRIMEM["Greenwich",0.0,  
> AUTHORITY["EPSG","8901"]], UNIT["degree",0.017453292519943295],  
> AXIS["Geodetic latitude",NORTH], AXIS["Geodetic longitude",EAST],  
> AXIS["Ellipsoidal height",UP], AUTHORITY["EPSG","4979"]]
>
> Josh
>
> On Aug 28, 2009, at 1:05 PM, Ron Lake wrote:
>
>  
>> Sorry my example should have been
>>
>> <Point id = "P1"  CRS = "http://www.blah.bla/standardCRS.xml">
>> <coordinates>100 200  150</coordinates>
>> </Point>
>>
>> But the argument is the same.  Similar encodings can be made in JSON
>> etc.
>>
>> R
>>
>> -----Original Message-----
>> From: georss-bounces@...
>> [mailto:georss-bounces@...] On Behalf Of Andrew Turner
>> Sent: August 28, 2009 9:57 AM
>> To: geowanking@...; GeoRSS; geojson
>> Subject: Re: [georss] [Geojson] simple 3D geocode for AR
>>
>> Simplest?
>>
>> Just include a 3rd coordinate in GeoRSS-Simple point or GeoJSON

point.
>>
>> No, this is not explicitly valid. But you see where that discussion
>> gets us. Long windy roads of elusive semantic talk (arguably
necessary
>> in the lon term, but not simple or useable *now*, which is when
people

>> are building these tools).
>>
>> If we lose interest without achieving a near term concensus,
>> developers will just do arbitrary, different solutions. Give them a
>> simple answer now, even if it makes your strict-validation-only-skin
>> crawl just a little bit. :)
>>
>> So I say just do it, and we'll catch up with documenting it as uses
>> emerge.
>>
>> Also, KML already supports 3D points.
>>
>> Andrew
>>
>>
>>
>> (via mobile)
>>
>> On Aug 27, 2009, at 4:35 PM, Mike Liebhold <mnl@...> wrote:
>>
>>    
>>> A friend wrote me with a request for clarification on a topic we've
>>> discussed many times here,  but every time we've approached a
>>> consensus the answer seems elusive.
>>>
>>> Many devleopers are starting to create applications for iPhones and
>>> Android phones to view location specific data  through the
>>> viewfinder using the -imprecise- capabilities of the built in gps
>>> and compass and applications platforms like Layar.
>>>
>>> The question:
>>>
>>> What is the -simplest- way to geocode a geoannotation in 3D using
>>> geoRSS/Atom, geojson, KML ....?
>>>
>>> (Is there a practical reason why WGS '84 shouldn't be implicit, and
>>> a CRS  lookup NOT be required?)
>>>
>>>
>>> _______________________________________________
>>> Geojson mailing list
>>> Geojson@...
>>> http://lists.geojson.org/listinfo.cgi/geojson-geojson.org
>>>      
>> _______________________________________________
>> georss mailing list
>> georss@...
>> http://lists.eogeo.org/mailman/listinfo/georss
>> _______________________________________________
>> georss mailing list
>> georss@...
>> http://lists.eogeo.org/mailman/listinfo/georss
>>    
>
> _______________________________________________
> georss mailing list
> georss@...
> http://lists.eogeo.org/mailman/listinfo/georss
> _______________________________________________
> georss mailing list
> georss@...
> http://lists.eogeo.org/mailman/listinfo/georss
>
>
>  

_______________________________________________
georss mailing list
georss@...
http://lists.eogeo.org/mailman/listinfo/georss

[Marten Hogeweg]

There is more to it that 'where are you and what direction are you looking in'.

For specifying a view for a camera, this may have some guidance:
http://graphics.stanford.edu/~cek/rayshade/doc/guide/chapter2_5.html#SECTION0050000000000000000

it's the Rayshade User's Guide and Reference Manual, Craig E. Kolb, Draft 0.4, January 10, 1992 (!)

"The three basic camera properties are its position, the direction in which it is pointing, and its orientation.

Another important choice to be made is that of the field of view of the camera. The size of this field describes the angles between the left and right sides and top and bottom sides of the frustum."


Marten
http://twitter.com/martehogeweg 

-----Original Message-----
From: georss-bounces@... [mailto:georss-bounces@...] On Behalf Of Ron Lake
Sent: Friday, August 28, 2009 3:10 PM
To: Mike Liebhold
Cc: geojson; geowanking@...; GeoRSS
Subject: Re: [georss] [Geojson] simple 3D geocode for AR

Sure.

Location of the camera - where in the world are you.  For this
geographic coordinates - e.g. (lat,lon) makes sense.

Now in the field of view of the camera, I can see things.  I am
interested in their shape, location etc. relative to the camera or
relative to me, the holder of the camera.  The most logical coordinate
system for locating such items is a rectilinear coordinate system (x-y-z
frame) centered (origin) at the focal point of the camera.  

Cheers

Ron


-----Original Message-----
From: Mike Liebhold [mailto:mnl@...]
Sent: August 28, 2009 2:05 PM
To: Ron Lake
Cc: Joshua Lieberman; geowanking@...; geojson; GeoRSS
Subject: Re: [georss] [Geojson] simple 3D geocode for AR

Ron Lake wrote:
> The use of geographic coordinates for [location of things in the field
of view relative to the camera]  likely does not. [ make sense]
>  

Ron,

This is really counter intuitive, Can you explain what you mean?

- Mike

>
> -----Original Message-----
> From: georss-bounces@...
> [mailto:georss-bounces@...] On Behalf Of Joshua Lieberman
> Sent: August 28, 2009 11:03 AM
> To: geowanking@...
> Cc: geojson; GeoRSS
> Subject: Re: [georss] [Geojson] simple 3D geocode for AR
>
> In both GeoRSS GML and GeoJSON, some explicit CRS needs to be  
> specified to use 3-coordinate locations. The simplest one for GeoRSS  
> seems to be epsg:4979 ( urn:ogc:def:crs:EPSG:4979 ). It would need a  
> slight modification to support the GeoJSON long-lat encoding.  
> Otherwise use GeoRSS Simple and the elev property.
>
> e.g.
>
> <georss:elev>346</georss:elev>
> <georss:point>42.3234 -173.234134</georss:point>
>
> Well-known text description of 4979
> (http://spatialreference.org/ref/epsg/4979/ 
> )
> GEOGCS["WGS 84", DATUM["World Geodetic System 1984", SPHEROID["WGS

84",

> 6378137.0,298.257223563, AUTHORITY["EPSG","7030"]],          
> AUTHORITY["EPSG","6326"]], PRIMEM["Greenwich",0.0,  
> AUTHORITY["EPSG","8901"]], UNIT["degree",0.017453292519943295],  
> AXIS["Geodetic latitude",NORTH], AXIS["Geodetic longitude",EAST],  
> AXIS["Ellipsoidal height",UP], AUTHORITY["EPSG","4979"]]
>
> Josh
>
> On Aug 28, 2009, at 1:05 PM, Ron Lake wrote:
>
>  
>> Sorry my example should have been
>>
>> <Point id = "P1"  CRS = "http://www.blah.bla/standardCRS.xml">
>> <coordinates>100 200  150</coordinates>
>> </Point>
>>
>> But the argument is the same.  Similar encodings can be made in JSON
>> etc.
>>
>> R
>>
>> -----Original Message-----
>> From: georss-bounces@...
>> [mailto:georss-bounces@...] On Behalf Of Andrew Turner
>> Sent: August 28, 2009 9:57 AM
>> To: geowanking@...; GeoRSS; geojson
>> Subject: Re: [georss] [Geojson] simple 3D geocode for AR
>>
>> Simplest?
>>
>> Just include a 3rd coordinate in GeoRSS-Simple point or GeoJSON

point.
>>
>> No, this is not explicitly valid. But you see where that discussion
>> gets us. Long windy roads of elusive semantic talk (arguably
necessary
>> in the lon term, but not simple or useable *now*, which is when
people

>> are building these tools).
>>
>> If we lose interest without achieving a near term concensus,
>> developers will just do arbitrary, different solutions. Give them a
>> simple answer now, even if it makes your strict-validation-only-skin
>> crawl just a little bit. :)
>>
>> So I say just do it, and we'll catch up with documenting it as uses
>> emerge.
>>
>> Also, KML already supports 3D points.
>>
>> Andrew
>>
>>
>>
>> (via mobile)
>>
>> On Aug 27, 2009, at 4:35 PM, Mike Liebhold <mnl@...> wrote:
>>
>>    
>>> A friend wrote me with a request for clarification on a topic we've
>>> discussed many times here,  but every time we've approached a
>>> consensus the answer seems elusive.
>>>
>>> Many devleopers are starting to create applications for iPhones and
>>> Android phones to view location specific data  through the
>>> viewfinder using the -imprecise- capabilities of the built in gps
>>> and compass and applications platforms like Layar.
>>>
>>> The question:
>>>
>>> What is the -simplest- way to geocode a geoannotation in 3D using
>>> geoRSS/Atom, geojson, KML ....?
>>>
>>> (Is there a practical reason why WGS '84 shouldn't be implicit, and
>>> a CRS  lookup NOT be required?)
>>>
>>>
>>> _______________________________________________
>>> Geojson mailing list
>>> Geojson@...
>>> http://lists.geojson.org/listinfo.cgi/geojson-geojson.org
>>>      
>> _______________________________________________
>> georss mailing list
>> georss@...
>> http://lists.eogeo.org/mailman/listinfo/georss
>> _______________________________________________
>> georss mailing list
>> georss@...
>> http://lists.eogeo.org/mailman/listinfo/georss
>>    
>
> _______________________________________________
> georss mailing list
> georss@...
> http://lists.eogeo.org/mailman/listinfo/georss
> _______________________________________________
> georss mailing list
> georss@...
> http://lists.eogeo.org/mailman/listinfo/georss
>
>
>  

_______________________________________________
georss mailing list
georss@...
http://lists.eogeo.org/mailman/listinfo/georss

_______________________________________________
georss mailing list
georss@...
http://lists.eogeo.org/mailman/listinfo/georss

[Ron Lake]

Hi,

I think you missed my point.  We were talking about coordinate systems,
and I was only making the point that more than one CRS is likely
required. The look vector field of the camera would be best expressed
also relative to a local coordinate system.

Cheers

Ron

-----Original Message-----
From: Marten Hogeweg [mailto:mhogeweg@...]
Sent: August 28, 2009 3:23 PM
To: Ron Lake; Mike Liebhold
Cc: geojson; geowanking@...; GeoRSS
Subject: RE: [georss] [Geojson] simple 3D geocode for AR

There is more to it that 'where are you and what direction are you
looking in'.

For specifying a view for a camera, this may have some guidance:
http://graphics.stanford.edu/~cek/rayshade/doc/guide/chapter2_5.html#SEC
TION0050000000000000000

it's the Rayshade User's Guide and Reference Manual, Craig E. Kolb,
Draft 0.4, January 10, 1992 (!)

"The three basic camera properties are its position, the direction in
which it is pointing, and its orientation.

Another important choice to be made is that of the field of view of the
camera. The size of this field describes the angles between the left and
right sides and top and bottom sides of the frustum."


Marten
http://twitter.com/martehogeweg 

-----Original Message-----
From: georss-bounces@...
[mailto:georss-bounces@...] On Behalf Of Ron Lake
Sent: Friday, August 28, 2009 3:10 PM
To: Mike Liebhold
Cc: geojson; geowanking@...; GeoRSS
Subject: Re: [georss] [Geojson] simple 3D geocode for AR

Sure.

Location of the camera - where in the world are you.  For this
geographic coordinates - e.g. (lat,lon) makes sense.

Now in the field of view of the camera, I can see things.  I am
interested in their shape, location etc. relative to the camera or
relative to me, the holder of the camera.  The most logical coordinate
system for locating such items is a rectilinear coordinate system (x-y-z
frame) centered (origin) at the focal point of the camera.  

Cheers

Ron


-----Original Message-----
From: Mike Liebhold [mailto:mnl@...]
Sent: August 28, 2009 2:05 PM
To: Ron Lake
Cc: Joshua Lieberman; geowanking@...; geojson; GeoRSS
Subject: Re: [georss] [Geojson] simple 3D geocode for AR

Ron Lake wrote:
> The use of geographic coordinates for [location of things in the field
of view relative to the camera]  likely does not. [ make sense]
>  

Ron,

This is really counter intuitive, Can you explain what you mean?

- Mike

>
> -----Original Message-----
> From: georss-bounces@...
> [mailto:georss-bounces@...] On Behalf Of Joshua Lieberman
> Sent: August 28, 2009 11:03 AM
> To: geowanking@...
> Cc: geojson; GeoRSS
> Subject: Re: [georss] [Geojson] simple 3D geocode for AR
>
> In both GeoRSS GML and GeoJSON, some explicit CRS needs to be  
> specified to use 3-coordinate locations. The simplest one for GeoRSS  
> seems to be epsg:4979 ( urn:ogc:def:crs:EPSG:4979 ). It would need a  
> slight modification to support the GeoJSON long-lat encoding.  
> Otherwise use GeoRSS Simple and the elev property.
>
> e.g.
>
> <georss:elev>346</georss:elev>
> <georss:point>42.3234 -173.234134</georss:point>
>
> Well-known text description of 4979
> (http://spatialreference.org/ref/epsg/4979/ 
> )
> GEOGCS["WGS 84", DATUM["World Geodetic System 1984", SPHEROID["WGS

84",

> 6378137.0,298.257223563, AUTHORITY["EPSG","7030"]],          
> AUTHORITY["EPSG","6326"]], PRIMEM["Greenwich",0.0,  
> AUTHORITY["EPSG","8901"]], UNIT["degree",0.017453292519943295],  
> AXIS["Geodetic latitude",NORTH], AXIS["Geodetic longitude",EAST],  
> AXIS["Ellipsoidal height",UP], AUTHORITY["EPSG","4979"]]
>
> Josh
>
> On Aug 28, 2009, at 1:05 PM, Ron Lake wrote:
>
>  
>> Sorry my example should have been
>>
>> <Point id = "P1"  CRS = "http://www.blah.bla/standardCRS.xml">
>> <coordinates>100 200  150</coordinates>
>> </Point>
>>
>> But the argument is the same.  Similar encodings can be made in JSON
>> etc.
>>
>> R
>>
>> -----Original Message-----
>> From: georss-bounces@...
>> [mailto:georss-bounces@...] On Behalf Of Andrew Turner
>> Sent: August 28, 2009 9:57 AM
>> To: geowanking@...; GeoRSS; geojson
>> Subject: Re: [georss] [Geojson] simple 3D geocode for AR
>>
>> Simplest?
>>
>> Just include a 3rd coordinate in GeoRSS-Simple point or GeoJSON

point.
>>
>> No, this is not explicitly valid. But you see where that discussion
>> gets us. Long windy roads of elusive semantic talk (arguably
necessary
>> in the lon term, but not simple or useable *now*, which is when
people

>> are building these tools).
>>
>> If we lose interest without achieving a near term concensus,
>> developers will just do arbitrary, different solutions. Give them a
>> simple answer now, even if it makes your strict-validation-only-skin
>> crawl just a little bit. :)
>>
>> So I say just do it, and we'll catch up with documenting it as uses
>> emerge.
>>
>> Also, KML already supports 3D points.
>>
>> Andrew
>>
>>
>>
>> (via mobile)
>>
>> On Aug 27, 2009, at 4:35 PM, Mike Liebhold <mnl@...> wrote:
>>
>>    
>>> A friend wrote me with a request for clarification on a topic we've
>>> discussed many times here,  but every time we've approached a
>>> consensus the answer seems elusive.
>>>
>>> Many devleopers are starting to create applications for iPhones and
>>> Android phones to view location specific data  through the
>>> viewfinder using the -imprecise- capabilities of the built in gps
>>> and compass and applications platforms like Layar.
>>>
>>> The question:
>>>
>>> What is the -simplest- way to geocode a geoannotation in 3D using
>>> geoRSS/Atom, geojson, KML ....?
>>>
>>> (Is there a practical reason why WGS '84 shouldn't be implicit, and
>>> a CRS  lookup NOT be required?)
>>>
>>>
>>> _______________________________________________
>>> Geojson mailing list
>>> Geojson@...
>>> http://lists.geojson.org/listinfo.cgi/geojson-geojson.org
>>>      
>> _______________________________________________
>> georss mailing list
>> georss@...
>> http://lists.eogeo.org/mailman/listinfo/georss
>> _______________________________________________
>> georss mailing list
>> georss@...
>> http://lists.eogeo.org/mailman/listinfo/georss
>>    
>
> _______________________________________________
> georss mailing list
> georss@...
> http://lists.eogeo.org/mailman/listinfo/georss
> _______________________________________________
> georss mailing list
> georss@...
> http://lists.eogeo.org/mailman/listinfo/georss
>
>
>  

_______________________________________________
georss mailing list
georss@...
http://lists.eogeo.org/mailman/listinfo/georss

_______________________________________________
georss mailing list
georss@...
http://lists.eogeo.org/mailman/listinfo/georss

[Mike Liebhold]

Ron Lake wrote:
>  The most logical coordinate
> system for locating such items is a rectilinear coordinate system (x-y-z
> frame) centered (origin) at the focal point of the camera.  
>  
What's the use case?

In most cases, we probably can assume that the geo-annotations exist
independent of the viewpoint; e.g. a viewer should be able to see the
note attached to a restaurant from any perspective as they pass on a
sidewalk, or drive by.

 In that case, we need absolute coordinates, not relative to the camera
perspective.

imho

Mike

> Cheers
>
> Ron
>
>
> -----Original Message-----
> From: Mike Liebhold [mailto:mnl@...]
> Sent: August 28, 2009 2:05 PM
> To: Ron Lake
> Cc: Joshua Lieberman; geowanking@...; geojson; GeoRSS
> Subject: Re: [georss] [Geojson] simple 3D geocode for AR
>
> Ron Lake wrote:
>  
>> The use of geographic coordinates for [location of things in the field
>>    
> of view relative to the camera]  likely does not. [ make sense]
>  
>>  
>>    
>
> Ron,
>
> This is really counter intuitive, Can you explain what you mean?
>
> - Mike
>  
>> -----Original Message-----
>> From: georss-bounces@...
>> [mailto:georss-bounces@...] On Behalf Of Joshua Lieberman
>> Sent: August 28, 2009 11:03 AM
>> To: geowanking@...
>> Cc: geojson; GeoRSS
>> Subject: Re: [georss] [Geojson] simple 3D geocode for AR
>>
>> In both GeoRSS GML and GeoJSON, some explicit CRS needs to be  
>> specified to use 3-coordinate locations. The simplest one for GeoRSS  
>> seems to be epsg:4979 ( urn:ogc:def:crs:EPSG:4979 ). It would need a  
>> slight modification to support the GeoJSON long-lat encoding.  
>> Otherwise use GeoRSS Simple and the elev property.
>>
>> e.g.
>>
>> <georss:elev>346</georss:elev>
>> <georss:point>42.3234 -173.234134</georss:point>
>>
>> Well-known text description of 4979
>> (http://spatialreference.org/ref/epsg/4979/ 
>> )
>> GEOGCS["WGS 84", DATUM["World Geodetic System 1984", SPHEROID["WGS
>>    
> 84",
>  
>> 6378137.0,298.257223563, AUTHORITY["EPSG","7030"]],          
>> AUTHORITY["EPSG","6326"]], PRIMEM["Greenwich",0.0,  
>> AUTHORITY["EPSG","8901"]], UNIT["degree",0.017453292519943295],  
>> AXIS["Geodetic latitude",NORTH], AXIS["Geodetic longitude",EAST],  
>> AXIS["Ellipsoidal height",UP], AUTHORITY["EPSG","4979"]]
>>
>> Josh
>>
>> On Aug 28, 2009, at 1:05 PM, Ron Lake wrote:
>>
>>  
>>    
>>> Sorry my example should have been
>>>
>>> <Point id = "P1"  CRS = "http://www.blah.bla/standardCRS.xml">
>>> <coordinates>100 200  150</coordinates>
>>> </Point>
>>>
>>> But the argument is the same.  Similar encodings can be made in JSON
>>> etc.
>>>
>>> R
>>>
>>> -----Original Message-----
>>> From: georss-bounces@...
>>> [mailto:georss-bounces@...] On Behalf Of Andrew Turner
>>> Sent: August 28, 2009 9:57 AM
>>> To: geowanking@...; GeoRSS; geojson
>>> Subject: Re: [georss] [Geojson] simple 3D geocode for AR
>>>
>>> Simplest?
>>>
>>> Just include a 3rd coordinate in GeoRSS-Simple point or GeoJSON
>>>      
> point.
>  
>>> No, this is not explicitly valid. But you see where that discussion
>>> gets us. Long windy roads of elusive semantic talk (arguably
>>>      
> necessary
>  
>>> in the lon term, but not simple or useable *now*, which is when
>>>      
> people
>  
>>> are building these tools).
>>>
>>> If we lose interest without achieving a near term concensus,
>>> developers will just do arbitrary, different solutions. Give them a
>>> simple answer now, even if it makes your strict-validation-only-skin
>>> crawl just a little bit. :)
>>>
>>> So I say just do it, and we'll catch up with documenting it as uses
>>> emerge.
>>>
>>> Also, KML already supports 3D points.
>>>
>>> Andrew
>>>
>>>
>>>
>>> (via mobile)
>>>
>>> On Aug 27, 2009, at 4:35 PM, Mike Liebhold <mnl@...> wrote:
>>>
>>>    
>>>      
>>>> A friend wrote me with a request for clarification on a topic we've
>>>> discussed many times here,  but every time we've approached a
>>>> consensus the answer seems elusive.
>>>>
>>>> Many devleopers are starting to create applications for iPhones and
>>>> Android phones to view location specific data  through the
>>>> viewfinder using the -imprecise- capabilities of the built in gps
>>>> and compass and applications platforms like Layar.
>>>>
>>>> The question:
>>>>
>>>> What is the -simplest- way to geocode a geoannotation in 3D using
>>>> geoRSS/Atom, geojson, KML ....?
>>>>
>>>> (Is there a practical reason why WGS '84 shouldn't be implicit, and
>>>> a CRS  lookup NOT be required?)
>>>>
>>>>
>>>> _______________________________________________
>>>> Geojson mailing list
>>>> Geojson@...
>>>> http://lists.geojson.org/listinfo.cgi/geojson-geojson.org
>>>>      
>>>>        
>>> _______________________________________________
>>> georss mailing list
>>> georss@...
>>> http://lists.eogeo.org/mailman/listinfo/georss
>>> _______________________________________________
>>> georss mailing list
>>> georss@...
>>> http://lists.eogeo.org/mailman/listinfo/georss
>>>    
>>>      
>> _______________________________________________
>> georss mailing list
>> georss@...
>> http://lists.eogeo.org/mailman/listinfo/georss
>> _______________________________________________
>> georss mailing list
>> georss@...
>> http://lists.eogeo.org/mailman/listinfo/georss
>>
>>
>>  
>>    
>
>
>  

_______________________________________________
georss mailing list
georss@...
http://lists.eogeo.org/mailman/listinfo/georss

[Ron Lake]

My anticipation is BOTH cases are important.

R

-----Original Message-----
From: Mike Liebhold [mailto:mnl@...]
Sent: August 28, 2009 4:35 PM
To: Ron Lake
Cc: geowanking@...; geojson; GeoRSS
Subject: Re: [georss] [Geojson] simple 3D geocode for AR

Ron Lake wrote:
>  The most logical coordinate
> system for locating such items is a rectilinear coordinate system
(x-y-z
> frame) centered (origin) at the focal point of the camera.  
>  
What's the use case?

In most cases, we probably can assume that the geo-annotations exist
independent of the viewpoint; e.g. a viewer should be able to see the
note attached to a restaurant from any perspective as they pass on a
sidewalk, or drive by.

 In that case, we need absolute coordinates, not relative to the camera
perspective.

imho

Mike

> Cheers
>
> Ron
>
>
> -----Original Message-----
> From: Mike Liebhold [mailto:mnl@...]
> Sent: August 28, 2009 2:05 PM
> To: Ron Lake
> Cc: Joshua Lieberman; geowanking@...; geojson; GeoRSS
> Subject: Re: [georss] [Geojson] simple 3D geocode for AR
>
> Ron Lake wrote:
>  
>> The use of geographic coordinates for [location of things in the

field

>>    
> of view relative to the camera]  likely does not. [ make sense]
>  
>>  
>>    
>
> Ron,
>
> This is really counter intuitive, Can you explain what you mean?
>
> - Mike
>  
>> -----Original Message-----
>> From: georss-bounces@...
>> [mailto:georss-bounces@...] On Behalf Of Joshua Lieberman
>> Sent: August 28, 2009 11:03 AM
>> To: geowanking@...
>> Cc: geojson; GeoRSS
>> Subject: Re: [georss] [Geojson] simple 3D geocode for AR
>>
>> In both GeoRSS GML and GeoJSON, some explicit CRS needs to be  
>> specified to use 3-coordinate locations. The simplest one for GeoRSS

>> seems to be epsg:4979 ( urn:ogc:def:crs:EPSG:4979 ). It would need a

>> slight modification to support the GeoJSON long-lat encoding.  
>> Otherwise use GeoRSS Simple and the elev property.
>>
>> e.g.
>>
>> <georss:elev>346</georss:elev>
>> <georss:point>42.3234 -173.234134</georss:point>
>>
>> Well-known text description of 4979
>> (http://spatialreference.org/ref/epsg/4979/ 
>> )
>> GEOGCS["WGS 84", DATUM["World Geodetic System 1984", SPHEROID["WGS
>>    
> 84",
>  
>> 6378137.0,298.257223563, AUTHORITY["EPSG","7030"]],          
>> AUTHORITY["EPSG","6326"]], PRIMEM["Greenwich",0.0,  
>> AUTHORITY["EPSG","8901"]], UNIT["degree",0.017453292519943295],  
>> AXIS["Geodetic latitude",NORTH], AXIS["Geodetic longitude",EAST],  
>> AXIS["Ellipsoidal height",UP], AUTHORITY["EPSG","4979"]]
>>
>> Josh
>>
>> On Aug 28, 2009, at 1:05 PM, Ron Lake wrote:
>>
>>  
>>    
>>> Sorry my example should have been
>>>
>>> <Point id = "P1"  CRS = "http://www.blah.bla/standardCRS.xml">
>>> <coordinates>100 200  150</coordinates>
>>> </Point>
>>>
>>> But the argument is the same.  Similar encodings can be made in JSON
>>> etc.
>>>
>>> R
>>>
>>> -----Original Message-----
>>> From: georss-bounces@...
>>> [mailto:georss-bounces@...] On Behalf Of Andrew Turner
>>> Sent: August 28, 2009 9:57 AM
>>> To: geowanking@...; GeoRSS; geojson
>>> Subject: Re: [georss] [Geojson] simple 3D geocode for AR
>>>
>>> Simplest?
>>>
>>> Just include a 3rd coordinate in GeoRSS-Simple point or GeoJSON
>>>      
> point.
>  
>>> No, this is not explicitly valid. But you see where that discussion
>>> gets us. Long windy roads of elusive semantic talk (arguably
>>>      
> necessary
>  
>>> in the lon term, but not simple or useable *now*, which is when
>>>      
> people
>  
>>> are building these tools).
>>>
>>> If we lose interest without achieving a near term concensus,
>>> developers will just do arbitrary, different solutions. Give them a
>>> simple answer now, even if it makes your strict-validation-only-skin
>>> crawl just a little bit. :)
>>>
>>> So I say just do it, and we'll catch up with documenting it as uses
>>> emerge.
>>>
>>> Also, KML already supports 3D points.
>>>
>>> Andrew
>>>
>>>
>>>
>>> (via mobile)
>>>
>>> On Aug 27, 2009, at 4:35 PM, Mike Liebhold <mnl@...> wrote:
>>>
>>>    
>>>      
>>>> A friend wrote me with a request for clarification on a topic we've
>>>> discussed many times here,  but every time we've approached a
>>>> consensus the answer seems elusive.
>>>>
>>>> Many devleopers are starting to create applications for iPhones and
>>>> Android phones to view location specific data  through the
>>>> viewfinder using the -imprecise- capabilities of the built in gps
>>>> and compass and applications platforms like Layar.
>>>>
>>>> The question:
>>>>
>>>> What is the -simplest- way to geocode a geoannotation in 3D using
>>>> geoRSS/Atom, geojson, KML ....?
>>>>
>>>> (Is there a practical reason why WGS '84 shouldn't be implicit, and
>>>> a CRS  lookup NOT be required?)
>>>>
>>>>
>>>> _______________________________________________
>>>> Geojson mailing list
>>>> Geojson@...
>>>> http://lists.geojson.org/listinfo.cgi/geojson-geojson.org
>>>>      
>>>>        
>>> _______________________________________________
>>> georss mailing list
>>> georss@...
>>> http://lists.eogeo.org/mailman/listinfo/georss
>>> _______________________________________________
>>> georss mailing list
>>> georss@...
>>> http://lists.eogeo.org/mailman/listinfo/georss
>>>    
>>>      
>> _______________________________________________
>> georss mailing list
>> georss@...
>> http://lists.eogeo.org/mailman/listinfo/georss
>> _______________________________________________
>> georss mailing list
>> georss@...
>> http://lists.eogeo.org/mailman/listinfo/georss
>>
>>
>>  
>>    
>
>
>  

_______________________________________________
georss mailing list
georss@...
http://lists.eogeo.org/mailman/listinfo/georss

[chris goad-2]

Ron Lake wrote:

>I suspect that in augmented reality applications you are going to want
> to express the location of the camera (determined by GPS) and the
> location of things in the field of view relative to the camera.

But maybe not in the context of the Geocoding-for-AR problem.  An AR device
needs to be able to compute visibility to its camera of features  in
geocoded data.  It follows that  a camera model is required within the
device's own software, but not that the geocoded data needs representations
of cameras.

-- Chris


----- Original Message -----
From: "Ron Lake" <rlake@...>
To: "Mike Liebhold" <mnl@...>
Cc: "geojson" <geojson@...>; <geowanking@...>;
"GeoRSS" <georss@...>
Sent: Friday, August 28, 2009 3:10 PM
Subject: Re: [georss] [Geojson] simple 3D geocode for AR

> Sure.
>
> Location of the camera - where in the world are you.  For this
> geographic coordinates - e.g. (lat,lon) makes sense.
>
> Now in the field of view of the camera, I can see things.  I am
> interested in their shape, location etc. relative to the camera or
> relative to me, the holder of the camera.  The most logical coordinate
> system for locating such items is a rectilinear coordinate system (x-y-z
> frame) centered (origin) at the focal point of the camera.
>
> Cheers
>
> Ron
>
>
> -----Original Message-----
> From: Mike Liebhold [mailto:mnl@...]
> Sent: August 28, 2009 2:05 PM
> To: Ron Lake
> Cc: Joshua Lieberman; geowanking@...; geojson; GeoRSS
> Subject: Re: [georss] [Geojson] simple 3D geocode for AR
>
> Ron Lake wrote:
>> The use of geographic coordinates for [location of things in the field
> of view relative to the camera]  likely does not. [ make sense]
>>
>
> Ron,
>
> This is really counter intuitive, Can you explain what you mean?
>
> - Mike
>>
>> -----Original Message-----
>> From: georss-bounces@...
>> [mailto:georss-bounces@...] On Behalf Of Joshua Lieberman
>> Sent: August 28, 2009 11:03 AM
>> To: geowanking@...
>> Cc: geojson; GeoRSS
>> Subject: Re: [georss] [Geojson] simple 3D geocode for AR
>>
>> In both GeoRSS GML and GeoJSON, some explicit CRS needs to be
>> specified to use 3-coordinate locations. The simplest one for GeoRSS
>> seems to be epsg:4979 ( urn:ogc:def:crs:EPSG:4979 ). It would need a
>> slight modification to support the GeoJSON long-lat encoding.
>> Otherwise use GeoRSS Simple and the elev property.
>>
>> e.g.
>>
>> <georss:elev>346</georss:elev>
>> <georss:point>42.3234 -173.234134</georss:point>
>>
>> Well-known text description of 4979
>> (http://spatialreference.org/ref/epsg/4979/
>> )
>> GEOGCS["WGS 84", DATUM["World Geodetic System 1984", SPHEROID["WGS
> 84",
>> 6378137.0,298.257223563, AUTHORITY["EPSG","7030"]],
>> AUTHORITY["EPSG","6326"]], PRIMEM["Greenwich",0.0,
>> AUTHORITY["EPSG","8901"]], UNIT["degree",0.017453292519943295],
>> AXIS["Geodetic latitude",NORTH], AXIS["Geodetic longitude",EAST],
>> AXIS["Ellipsoidal height",UP], AUTHORITY["EPSG","4979"]]
>>
>> Josh
>>
>> On Aug 28, 2009, at 1:05 PM, Ron Lake wrote:
>>
>>
>>> Sorry my example should have been
>>>
>>> <Point id = "P1"  CRS = "http://www.blah.bla/standardCRS.xml">
>>> <coordinates>100 200  150</coordinates>
>>> </Point>
>>>
>>> But the argument is the same.  Similar encodings can be made in JSON
>>> etc.
>>>
>>> R
>>>
>>> -----Original Message-----
>>> From: georss-bounces@...
>>> [mailto:georss-bounces@...] On Behalf Of Andrew Turner
>>> Sent: August 28, 2009 9:57 AM
>>> To: geowanking@...; GeoRSS; geojson
>>> Subject: Re: [georss] [Geojson] simple 3D geocode for AR
>>>
>>> Simplest?
>>>
>>> Just include a 3rd coordinate in GeoRSS-Simple point or GeoJSON
> point.
>>>
>>> No, this is not explicitly valid. But you see where that discussion
>>> gets us. Long windy roads of elusive semantic talk (arguably
> necessary
>>> in the lon term, but not simple or useable *now*, which is when
> people
>>> are building these tools).
>>>
>>> If we lose interest without achieving a near term concensus,
>>> developers will just do arbitrary, different solutions. Give them a
>>> simple answer now, even if it makes your strict-validation-only-skin
>>> crawl just a little bit. :)
>>>
>>> So I say just do it, and we'll catch up with documenting it as uses
>>> emerge.
>>>
>>> Also, KML already supports 3D points.
>>>
>>> Andrew
>>>
>>>
>>>
>>> (via mobile)
>>>
>>> On Aug 27, 2009, at 4:35 PM, Mike Liebhold <mnl@...> wrote:
>>>
>>>
>>>> A friend wrote me with a request for clarification on a topic we've
>>>> discussed many times here,  but every time we've approached a
>>>> consensus the answer seems elusive.
>>>>
>>>> Many devleopers are starting to create applications for iPhones and
>>>> Android phones to view location specific data  through the
>>>> viewfinder using the -imprecise- capabilities of the built in gps
>>>> and compass and applications platforms like Layar.
>>>>
>>>> The question:
>>>>
>>>> What is the -simplest- way to geocode a geoannotation in 3D using
>>>> geoRSS/Atom, geojson, KML ....?
>>>>
>>>> (Is there a practical reason why WGS '84 shouldn't be implicit, and
>>>> a CRS  lookup NOT be required?)
>>>>
>>>>
>>>> _______________________________________________
>>>> Geojson mailing list
>>>> Geojson@...
>>>> http://lists.geojson.org/listinfo.cgi/geojson-geojson.org
>>>>
>>> _______________________________________________
>>> georss mailing list
>>> georss@...
>>> http://lists.eogeo.org/mailman/listinfo/georss
>>> _______________________________________________
>>> georss mailing list
>>> georss@...
>>> http://lists.eogeo.org/mailman/listinfo/georss
>>>
>>
>> _______________________________________________
>> georss mailing list
>> georss@...
>> http://lists.eogeo.org/mailman/listinfo/georss
>> _______________________________________________
>> georss mailing list
>> georss@...
>> http://lists.eogeo.org/mailman/listinfo/georss
>>
>>
>>
>
> _______________________________________________
> georss mailing list
> georss@...
> http://lists.eogeo.org/mailman/listinfo/georss 

_______________________________________________
georss mailing list
georss@...
http://lists.eogeo.org/mailman/listinfo/georss

[Ron Lake]

Mike:

Here is a simple use case. This use case does things using local
coordinates but not relative to the camera.  I point my camera at the
Eiffel tower.  The camera image is sent to a server that uses my
location and the camera image to determine that it is the Eiffel tower I
have imaged.  My AR application now overlays information (e.g. text with
arrows pointing at elements of the tower (like labels).  The items of
interest and their position are specified in a local coordinate system
(again rectilinear) relative to the tower.  This is the same as for 3D
models in GE or Bing - the coordinate system is not geographic.

Ron

-----Original Message-----
From: Mike Liebhold [mailto:mnl@...]
Sent: August 28, 2009 4:35 PM
To: Ron Lake
Cc: geowanking@...; geojson; GeoRSS
Subject: Re: [georss] [Geojson] simple 3D geocode for AR

Ron Lake wrote:
>  The most logical coordinate
> system for locating such items is a rectilinear coordinate system
(x-y-z
> frame) centered (origin) at the focal point of the camera.  
>  
What's the use case?

In most cases, we probably can assume that the geo-annotations exist
independent of the viewpoint; e.g. a viewer should be able to see the
note attached to a restaurant from any perspective as they pass on a
sidewalk, or drive by.

 In that case, we need absolute coordinates, not relative to the camera
perspective.

imho

Mike

> Cheers
>
> Ron
>
>
> -----Original Message-----
> From: Mike Liebhold [mailto:mnl@...]
> Sent: August 28, 2009 2:05 PM
> To: Ron Lake
> Cc: Joshua Lieberman; geowanking@...; geojson; GeoRSS
> Subject: Re: [georss] [Geojson] simple 3D geocode for AR
>
> Ron Lake wrote:
>  
>> The use of geographic coordinates for [location of things in the

field

>>    
> of view relative to the camera]  likely does not. [ make sense]
>  
>>  
>>    
>
> Ron,
>
> This is really counter intuitive, Can you explain what you mean?
>
> - Mike
>  
>> -----Original Message-----
>> From: georss-bounces@...
>> [mailto:georss-bounces@...] On Behalf Of Joshua Lieberman
>> Sent: August 28, 2009 11:03 AM
>> To: geowanking@...
>> Cc: geojson; GeoRSS
>> Subject: Re: [georss] [Geojson] simple 3D geocode for AR
>>
>> In both GeoRSS GML and GeoJSON, some explicit CRS needs to be  
>> specified to use 3-coordinate locations. The simplest one for GeoRSS

>> seems to be epsg:4979 ( urn:ogc:def:crs:EPSG:4979 ). It would need a

>> slight modification to support the GeoJSON long-lat encoding.  
>> Otherwise use GeoRSS Simple and the elev property.
>>
>> e.g.
>>
>> <georss:elev>346</georss:elev>
>> <georss:point>42.3234 -173.234134</georss:point>
>>
>> Well-known text description of 4979
>> (http://spatialreference.org/ref/epsg/4979/ 
>> )
>> GEOGCS["WGS 84", DATUM["World Geodetic System 1984", SPHEROID["WGS
>>    
> 84",
>  
>> 6378137.0,298.257223563, AUTHORITY["EPSG","7030"]],          
>> AUTHORITY["EPSG","6326"]], PRIMEM["Greenwich",0.0,  
>> AUTHORITY["EPSG","8901"]], UNIT["degree",0.017453292519943295],  
>> AXIS["Geodetic latitude",NORTH], AXIS["Geodetic longitude",EAST],  
>> AXIS["Ellipsoidal height",UP], AUTHORITY["EPSG","4979"]]
>>
>> Josh
>>
>> On Aug 28, 2009, at 1:05 PM, Ron Lake wrote:
>>
>>  
>>    
>>> Sorry my example should have been
>>>
>>> <Point id = "P1"  CRS = "http://www.blah.bla/standardCRS.xml">
>>> <coordinates>100 200  150</coordinates>
>>> </Point>
>>>
>>> But the argument is the same.  Similar encodings can be made in JSON
>>> etc.
>>>
>>> R
>>>
>>> -----Original Message-----
>>> From: georss-bounces@...
>>> [mailto:georss-bounces@...] On Behalf Of Andrew Turner
>>> Sent: August 28, 2009 9:57 AM
>>> To: geowanking@...; GeoRSS; geojson
>>> Subject: Re: [georss] [Geojson] simple 3D geocode for AR
>>>
>>> Simplest?
>>>
>>> Just include a 3rd coordinate in GeoRSS-Simple point or GeoJSON
>>>      
> point.
>  
>>> No, this is not explicitly valid. But you see where that discussion
>>> gets us. Long windy roads of elusive semantic talk (arguably
>>>      
> necessary
>  
>>> in the lon term, but not simple or useable *now*, which is when
>>>      
> people
>  
>>> are building these tools).
>>>
>>> If we lose interest without achieving a near term concensus,
>>> developers will just do arbitrary, different solutions. Give them a
>>> simple answer now, even if it makes your strict-validation-only-skin
>>> crawl just a little bit. :)
>>>
>>> So I say just do it, and we'll catch up with documenting it as uses
>>> emerge.
>>>
>>> Also, KML already supports 3D points.
>>>
>>> Andrew
>>>
>>>
>>>
>>> (via mobile)
>>>
>>> On Aug 27, 2009, at 4:35 PM, Mike Liebhold <mnl@...> wrote:
>>>
>>>    
>>>      
>>>> A friend wrote me with a request for clarification on a topic we've
>>>> discussed many times here,  but every time we've approached a
>>>> consensus the answer seems elusive.
>>>>
>>>> Many devleopers are starting to create applications for iPhones and
>>>> Android phones to view location specific data  through the
>>>> viewfinder using the -imprecise- capabilities of the built in gps
>>>> and compass and applications platforms like Layar.
>>>>
>>>> The question:
>>>>
>>>> What is the -simplest- way to geocode a geoannotation in 3D using
>>>> geoRSS/Atom, geojson, KML ....?
>>>>
>>>> (Is there a practical reason why WGS '84 shouldn't be implicit, and
>>>> a CRS  lookup NOT be required?)
>>>>
>>>>
>>>> _______________________________________________
>>>> Geojson mailing list
>>>> Geojson@...
>>>> http://lists.geojson.org/listinfo.cgi/geojson-geojson.org
>>>>      
>>>>        
>>> _______________________________________________
>>> georss mailing list
>>> georss@...
>>> http://lists.eogeo.org/mailman/listinfo/georss
>>> _______________________________________________
>>> georss mailing list
>>> georss@...
>>> http://lists.eogeo.org/mailman/listinfo/georss
>>>    
>>>      
>> _______________________________________________
>> georss mailing list
>> georss@...
>> http://lists.eogeo.org/mailman/listinfo/georss
>> _______________________________________________
>> georss mailing list
>> georss@...
>> http://lists.eogeo.org/mailman/listinfo/georss
>>
>>
>>  
>>    
>
>
>  

_______________________________________________
georss mailing list
georss@...
http://lists.eogeo.org/mailman/listinfo/georss

[chris goad-2]

Christian Willmes wrote:


> whats the problem here? Its simple coordiante transformation stuff... or
> do I miss something?!


Here's a concrete reformulation of Christian's question, with the simple
stuff written down:

An AR device asks the server: "I know that I am at X,Y,Z position relative
to object A (eg the Eiffel tower);  please tell me about features nearby in
rectilinear coordinates relative to A".  But the device can also ask "please
tell me about  A and the features nearby in WGS84; I'll do the math myself:"

x = 60*nauticalMileToMeter*(longitude(feature) -
longitude(A))*cosine(latitude(A)))
y  = 60*nauticalMileToMeter*(latitude(feature)-latitude(A))
z = altitude(feature)-altitude(A)

This is an approximation, but will work well for AR except in the case of
people using their devices from orbit.


--chris




----- Original Message -----
From: "Christian Willmes" <c.willmes@...>
To: "Mike Liebhold" <mnl@...>
Cc: "Ron Lake" <rlake@...>; "geojson" <geojson@...>;
<geowanking@...>; "GeoRSS" <georss@...>
Sent: Friday, August 28, 2009 6:00 PM
Subject: Re: [Geowanking] [georss] [Geojson] simple 3D geocode for AR

> Hi,
>
> whats the problem here? Its simple coordiante transformation stuff... or
> do I miss something?!
>
> The device gets the geocoordinates from the web, and computes those using
> its own position and orientation to local camera coordinates....
>
> its that simple... I think. ;-)
>
> regards,
> Christian
>
> Mike Liebhold schrieb:
>> Ron Lake wrote:
>>> The most logical coordinate
>>> system for locating such items is a rectilinear coordinate system (x-y-z
>>> frame) centered (origin) at the focal point of the camera.
>> What's the use case?
>>
>> In most cases, we probably can assume that the geo-annotations exist
>> independent of the viewpoint; e.g. a viewer should be able to see the
>> note attached to a restaurant from any perspective as they pass on a
>> sidewalk, or drive by.
>>
>> In that case, we need absolute coordinates, not relative to the camera
>> perspective.
>>
>> imho
>>
>> Mike
>>> Cheers
>>>
>>> Ron
>>>
>>>
>>> -----Original Message-----
>>> From: Mike Liebhold [mailto:mnl@...] Sent: August 28, 2009 2:05 PM
>>> To: Ron Lake
>>> Cc: Joshua Lieberman; geowanking@...; geojson; GeoRSS
>>> Subject: Re: [georss] [Geojson] simple 3D geocode for AR
>>>
>>> Ron Lake wrote:
>>>> The use of geographic coordinates for [location of things in the field
>>> of view relative to the camera] likely does not. [ make sense]
>>>
>>> Ron,
>>>
>>> This is really counter intuitive, Can you explain what you mean?
>>>
>>> - Mike
>>>> -----Original Message-----
>>>> From: georss-bounces@...
>>>> [mailto:georss-bounces@...] On Behalf Of Joshua Lieberman
>>>> Sent: August 28, 2009 11:03 AM
>>>> To: geowanking@...
>>>> Cc: geojson; GeoRSS
>>>> Subject: Re: [georss] [Geojson] simple 3D geocode for AR
>>>>
>>>> In both GeoRSS GML and GeoJSON, some explicit CRS needs to be specified
>>>> to use 3-coordinate locations. The simplest one for GeoRSS seems to be
>>>> epsg:4979 ( urn:ogc:def:crs:EPSG:4979 ). It would need a slight
>>>> modification to support the GeoJSON long-lat encoding. Otherwise use
>>>> GeoRSS Simple and the elev property.
>>>>
>>>> e.g.
>>>>
>>>> <georss:elev>346</georss:elev>
>>>> <georss:point>42.3234 -173.234134</georss:point>
>>>>
>>>> Well-known text description of 4979
>>>> (http://spatialreference.org/ref/epsg/4979/ )
>>>> GEOGCS["WGS 84", DATUM["World Geodetic System 1984", SPHEROID["WGS
>>> 84",
>>>> 6378137.0,298.257223563, AUTHORITY["EPSG","7030"]],
>>>> AUTHORITY["EPSG","6326"]], PRIMEM["Greenwich",0.0,
>>>> AUTHORITY["EPSG","8901"]], UNIT["degree",0.017453292519943295],
>>>> AXIS["Geodetic latitude",NORTH], AXIS["Geodetic longitude",EAST],
>>>> AXIS["Ellipsoidal height",UP], AUTHORITY["EPSG","4979"]]
>>>>
>>>> Josh
>>>>
>>>> On Aug 28, 2009, at 1:05 PM, Ron Lake wrote:
>>>>
>>>>> Sorry my example should have been
>>>>>
>>>>> <Point id = "P1" CRS = "http://www.blah.bla/standardCRS.xml">
>>>>> <coordinates>100 200 150</coordinates>
>>>>> </Point>
>>>>>
>>>>> But the argument is the same. Similar encodings can be made in JSON
>>>>> etc.
>>>>>
>>>>> R
>>>>>
>>>>> -----Original Message-----
>>>>> From: georss-bounces@...
>>>>> [mailto:georss-bounces@...] On Behalf Of Andrew Turner
>>>>> Sent: August 28, 2009 9:57 AM
>>>>> To: geowanking@...; GeoRSS; geojson
>>>>> Subject: Re: [georss] [Geojson] simple 3D geocode for AR
>>>>>
>>>>> Simplest?
>>>>>
>>>>> Just include a 3rd coordinate in GeoRSS-Simple point or GeoJSON
>>> point.
>>>>> No, this is not explicitly valid. But you see where that discussion
>>>>> gets us. Long windy roads of elusive semantic talk (arguably
>>> necessary
>>>>> in the lon term, but not simple or useable *now*, which is when
>>> people
>>>>> are building these tools).
>>>>>
>>>>> If we lose interest without achieving a near term concensus,
>>>>> developers will just do arbitrary, different solutions. Give them a
>>>>> simple answer now, even if it makes your strict-validation-only-skin
>>>>> crawl just a little bit. :)
>>>>>
>>>>> So I say just do it, and we'll catch up with documenting it as uses
>>>>> emerge.
>>>>>
>>>>> Also, KML already supports 3D points.
>>>>>
>>>>> Andrew
>>>>>
>>>>>
>>>>>
>>>>> (via mobile)
>>>>>
>>>>> On Aug 27, 2009, at 4:35 PM, Mike Liebhold <mnl@...> wrote:
>>>>>
>>>>>> A friend wrote me with a request for clarification on a topic we've
>>>>>> discussed many times here, but every time we've approached a
>>>>>> consensus the answer seems elusive.
>>>>>>
>>>>>> Many devleopers are starting to create applications for iPhones and
>>>>>> Android phones to view location specific data through the
>>>>>> viewfinder using the -imprecise- capabilities of the built in gps
>>>>>> and compass and applications platforms like Layar.
>>>>>>
>>>>>> The question:
>>>>>>
>>>>>> What is the -simplest- way to geocode a geoannotation in 3D using
>>>>>> geoRSS/Atom, geojson, KML ....?
>>>>>>
>>>>>> (Is there a practical reason why WGS '84 shouldn't be implicit, and
>>>>>> a CRS lookup NOT be required?)
>>>>>>
>>>>>>
>>>>>> _______________________________________________
>>>>>> Geojson mailing list
>>>>>> Geojson@...
>>>>>> http://lists.geojson.org/listinfo.cgi/geojson-geojson.org
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