[georss] elevation question

[Sean Gillies]

Why does GeoRSS recommend using 'georss:elev' over 3D tuples? 3D is
working out pretty well for KML.

Joshua Lieberman wrote:
> No, that is not the case.
> 
> If you have a single elevation generally associated with the item, you  
> can put that in the georss:elev or georss:floor property. As a  
> property, it doesn't belong inside georss:where alongside an object  
> such as gml:Point. Only one georss:where is supported per entry and  
> one geometry (for now) per georss:where element, so there is no  
> ambiguity.
> 
> If you have a need for a more complicated representation, as you  
> describe, then you are free to reference or specify a 3D / 4D / 5D  
> coordinate reference system (CRS) and supply multidimensional tuples  
> for every node, in accordance with ISO and OGC specifications for GML  
> geometries as supported in the gmlgeorss profile. Then you can specify  
> elevations for separate nodes on a linestring as you describe.
> 
> Cheers,
> 
> Josh
> 
> On Apr 8, 2008, at 1:05 AM, Makc wrote:
> 
>> so, what you're saying is that elevation can no longerbe associated
>> neither with individual shapes (since it does not go inside
>> <georss:where>), not to mention individual vertices, and instead is
>> only available for whatever the parent item is in the XML, i.e. only 1
>> elevation per item?
>>
>> so, for example, a line with two vertices one at 1m and other at 10m
>> elevation is not representable in georss/gml format?
>>
>> On Tue, Apr 8, 2008 at 3:51 AM, Joshua Lieberman <josh at oklieb.net>  
>> wrote:
>>> The schema updated for w3c geo 2007 makes georss:elev an independent
>>> attribute at the same level as georss:where, e.g.
>>>
>>>> <georss:where>
>>>> <gml:point>
>>>>   <gml:pos>blah blah</gml:pos>
>>>> </gml:point>
>>>> </georss:where>
>>>>
>>>> <georss:elev>313</georss:elev>
>>>>
>>> Same in Georss Simple:
>>>
>>> <georss:point>42.213 -133.123</georss:point>
>>>
>>> <georss:elev>313</georss:elev>
>>>
>>> The schema for both of these is described at
>>> http://www.georss.org/xml/1.1/overview . The site needs some more  
>>> updates,
>>> etc.
>>>
>>> Cheers,
>>>
>>> Josh
>>>
>>>
>>>
>>>
>>>
>>> On Apr 7, 2008, at 8:33 PM, Raj Singh wrote:
>>>
>>>>
>>>>
>>>> On Apr 7, 2008, at 4:34 PM, Makc wrote:
>>>>
>>>>> I have also found xsd file at
>>>>> http://www.georss.org/xml/1.0/georss.xsd, where elevation lands  
>>>>> under
>>>>> whereAttrGroup. I am not too good with these xsd things, but my
>>>>> interpretation is that, whenever someone wants to use elevation, it
>>>>> has to go inside <georss:where> together with <gml:something>, like
>>>>>
>>>>> <georss:where>
>>>>> <gml:point>blah blah</gml:point>
>>>>> <georss:elev>313</georss:elev>
>>>>> </georss:where>
>>>>>
>>>>> and not, for example, like
>>>>>
>>>>> <georss:where>
>>>>> <georss:point>blah blah</georss:point>
>>>>> <georss:elev>313</georss:elev>
>>>>> </georss:where>
>>>>>
>>>>> which does not really make sense to me, but it's like what it looks
>>>>> like ...
>>>>>
>>>> The XSD you reference only applies to GeoRSS GML
>>> (http://www.georss.org/gml
>>>> ).
>>>> There's no schema for GeoRSS Simple. In GeoRSS GML you would write:
>>>> <georss:where>
>>>> <gml:point>
>>>>   <gml:pos>blah blah</gml:pos>
>>>> </gml:point>
>>>> <georss:elev>313</georss:elev>
>>>> </georss:where>
>>>>
>>>> I can't help with figuring out which one is right for Simple...
>>>>
>>>> ---
>>>> Raj
>>>> _______________________________________________
>>>> georss mailing list
>>>> georss at lists.eogeo.org
>>>> http://lists.eogeo.org/mailman/listinfo/georss
>>>>
>>>
> 
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