Re: Agenda for Best Practice sub-group, 14:00UTC 1-June-2016

Hm, yes, good question. I did not remember that we made geo:Feature a geo:SpatialObject in the GeoSPARQL development. I agree with you, from the definitions this seems wrong. Perhaps that could be rediscussed, if there is a GeoSPARQL revision.

Clemens


On 1. Juni 2016 at 10:38:24, Andrea Perego (andrea.perego@jrc.ec.europa.eu<mailto:andrea.perego@jrc.ec.europa.eu>) wrote:

Hi, Clemens.

On 01/06/2016 8:26, Clemens Portele wrote:
> If we use 19107 as the basis, a TP_Object is a SpatialObject, too.
>
> This is the definition of "topological object" (the TP_Object):
> "spatial object representing spatial characteristics that are invariant
> under continuous transformations".
>
> The definition of "geometric object" (the GM_Object) is: "spatial object
> representing a geometric set" where geometric set is "a set of points".
>
> GeoSPARQL is consistent with this, geo:Geometry is a sub-class of
> geo:SpatialObject. If we would define xyz:Topology it should be a
> sub-class of geoSpatialObject, too.

What is unclear to me is why, in GeoSPARQL, feature is made a subclass
of spatial object.

Putting together the relevant ISO definitions:
- feature: "abstraction of real-world phenomena" (ISO 19101, 19107,
19109, 19156)
- spatial object: "object used for representing a spatial characteristic
of a feature" (ISO 19107)
- geometry (geometric object): "spatial object representing a geometric
set" (ISO 19107)

Based on them, a feature is not a spatial object - or I'm missing something?

Andrea


> Clemens
>
>
> On 1. Juni 2016 at 03:37:53, Joshua Lieberman
> (jlieberman@tumblingwalls.com <mailto:jlieberman@tumblingwalls.com>) wrote:
>
>> Yes, a GM_object instance is generally a geometry, but there can be
>> other spatial objects such as linear references, addresses,
>> placenames, etc. I’m pondering now whether TP_Object should also be a
>> subclass of SpatialObject, but I think it too is a form of spatial model.
>>
>> “Object” is vague, but possibly less confusing than “model” or
>> “representation”. The confusion may be a fundamental property of the
>> GFM, because one first models the worlds as features, then models the
>> features in turn as spatial objects. Making both feature and geometry
>> disjoint subclasses of spatial object in GeoSPARQL means, I think,
>> that SpatialObject really can’t mean anything except a step of removal
>> from owl:Thing.
>>
>> Josh
>>
>>> On May 31, 2016, at 9:11 PM, Rob Atkinson <rob@metalinkage.com.au
>>> <mailto:rob@metalinkage.com.au>> wrote:
>>>
>>> it all depends what you mean :-)
>>>
>>> I though a GM_object was specifically a geometry. As such it is
>>> independent of any real world thing - but it can be used as a
>>> property of a real world thing to define a spatial characteristic.
>>>
>>> as such I would say GM_Object and (real world thing) are disjoint.
>>>
>>> What I dont really understand is what a Spatial Object is, except it
>>> seems to declare that Egenhofer and other spatial operations can be
>>> supported on either GM_Object or GF_Feature.{geomproperty}. One
>>> wonders if a more elegant way of declaring this was possible without
>>> introducing a very strange abstract notion (and the confusion here I
>>> think is the evidence for the strangeness)
>>>
>>> OTOH running with the geoSPARQL as-is makes sense unless its provably
>>> broken in terms of the inferences it allows, so I'll just get over my
>>> distaste of incompatible naming vs. intent.
>>>
>>> Rob
>>>
>>>
>>>
>>>
>>> On Wed, 1 Jun 2016 at 09:58 Joshua Lieberman
>>> <jlieberman@tumblingwalls.com <mailto:jlieberman@tumblingwalls.com>>
>>> wrote:
>>>
>>> I’m questioning whether that is a good idea.
>>>
>>>
>>>
>>>> On May 31, 2016, at 7:43 PM, simon.cox@csiro.au
>>>> <mailto:simon.cox@csiro.au> wrote:
>>>>
>>>> In GeoSPARQL SpatialObject is superclass of geometry and spatial
>>>> feature.
>>>>
>>>> -----Original Message-----
>>>> From: Joshua Lieberman [mailto:jlieberman@tumblingwalls.com]
>>>> Sent: Wednesday, 1 June 2016 9:39 AM
>>>> To: Cox, Simon (L&W, Clayton) <Simon.Cox@csiro.au
>>>> <mailto:Simon.Cox@csiro.au>>
>>>> Cc: andrea.perego@jrc.ec.europa.eu
>>>> <mailto:andrea.perego@jrc.ec.europa.eu>;
>>>> l.vandenbrink@geonovum.nl <mailto:l.vandenbrink@geonovum.nl>;
>>>> frans.knibbe@geodan.nl <mailto:frans.knibbe@geodan.nl>;
>>>> public-sdw-wg@w3.org <mailto:public-sdw-wg@w3.org>
>>>> Subject: Re: Agenda for Best Practice sub-group, 14:00UTC
>>>> 1-June-2016
>>>>
>>>> Can't SpatialObject be disjoint from GF_Feature? Maybe it's
>>>> really SpatialRepresentation. Unless we want to call it
>>>> TransfinitePointSet.
>>>>
>>>>> On May 31, 2016, at 6:20 PM, simon.cox@csiro.au
>>>>> <mailto:simon.cox@csiro.au> wrote:
>>>>>
>>>>> That preserves the 'thing is not a subclass of geometry' axiom,
>>>>> but misses 'geometry is not a subclass of real-world-thing'.
>>>>> I don't see how to do that without a subclass of owl:Thing
>>>>> which is disjoint from GM_Object.
>>>>>
>>>>> Simon J D Cox
>>>>> Research Scientist
>>>>> Land and Water
>>>>> CSIRO
>>>>> E simon.cox@csiro.au <mailto:simon.cox@csiro.au> T +61 3 9545
>>>>> 2365 M +61 403 302 672
>>>>> Physical: Reception Central, Bayview Avenue, Clayton, Vic 3168
>>>>> Deliveries: Gate 3, Normanby Road, Clayton, Vic 3168
>>>>> Postal: Private Bag 10, Clayton South, Vic 3169
>>>>> people.csiro.au/C/S/Simon-Cox
>>>>> <http://people.csiro.au/C/S/Simon-Cox>
>>>>> orcid.org/0000-0002-3884-3420
>>>>> <http://orcid.org/0000-0002-3884-3420>
>>>>> researchgate.net/profile/Simon_Cox3
>>>>> <http://researchgate.net/profile/Simon_Cox3>
>>>>>
>>>>> ________________________________________
>>>>> From: Joshua Lieberman <jlieberman@tumblingwalls.com
>>>>> <mailto:jlieberman@tumblingwalls.com>>
>>>>> Sent: Wednesday, 1 June 2016 7:12 AM
>>>>> To: Andrea Perego
>>>>> Cc: Linda van den Brink; Frans Knibbe; SDW WG
>>>>> (public-sdw-wg@w3.org <mailto:public-sdw-wg@w3.org>)
>>>>> Subject: Re: Agenda for Best Practice sub-group, 14:00UTC
>>>>> 1-June-2016
>>>>>
>>>>>> On May 31, 2016, at 10:01 AM, Andrea Perego
>>>>>> <andrea.perego@jrc.ec.europa.eu
>>>>>> <mailto:andrea.perego@jrc.ec.europa.eu>> wrote:
>>>>>>
>>>>>> Dear Linda, dear Frans, dear Josh,
>>>>>>
>>>>>> About the agenda item on "spatial ontology", I wonder whether
>>>>>> we can include here a clarification on the notions of spatial
>>>>>> object, feature and geometry in GeoSPARQL - in relation to
>>>>>> ISO, and to our discussion on real-world / spatial things.
>>>>>>
>>>>>> In particular:
>>>>>>
>>>>>> 1. In GeoSPARQL, feature and geometry are explicitly mapped to
>>>>>> the corresponding notions in the relevant ISO standards.
>>>>>> However, the definition of spatial object in GeoSPARQL doesn't
>>>>>> seem to match to the ISO one ("object used for representing a
>>>>>> spatial characteristic of a feature" - ISO 19107).
>>>>>
>>>>> Yes, it's questionable whether GF_Feature should be considered
>>>>> a "Spatial Object". In ISO 19109, it's a real-world target of
>>>>> discourse, that can have properties, including one or more
>>>>> geometric model representations. I'm tending towards making
>>>>> GF_Feature an owl:Thing, and leaving GM_Object as a SpatialObject.
>>>>>>
>>>>>> 2. What in GeoSPARQL corresponds to real-world / spatial things?
>>>>>>
>>>>>> Thanks
>>>>>>
>>>>>> Andrea
>>>>>>
>>>>>>
>>>>>> On 30/05/2016 10:22, Linda van den Brink wrote:
>>>>>>> Hi all,
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>> The Best Practice sub-group telecon agenda is at
>>>>>>> https://www.w3.org/2015/spatial/wiki/Meetings:BP-Telecon20160601.

>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>> Main agenda:
>>>>>>>
>>>>>>> * Progress of BP Narrative 2
>>>>>>>
>>>>>>> * Spatial ontology
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>> See you all on Wednesday! (else please advise any regrets).
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>> Linda
>>>>>>>
>>>>>>
>>>>>> --
>>>>>> Andrea Perego, Ph.D.
>>>>>> Scientific / Technical Project Officer European Commission DG JRC
>>>>>> Institute for Environment & Sustainability Unit H06 - Digital
>>>>>> Earth &
>>>>>> Reference Data Via E. Fermi, 2749 - TP 262
>>>>>> 21027 Ispra VA, Italy
>>>>>>
>>>>>> https://ec.europa.eu/jrc/

>>>>>>
>>>>>>
>>>>>
>>>>>
>>>>>
>>>>
>>>>
>>>>
>>>>
>>>
>>> <SpatialObject.png><SpatialObject.png>
>>

--
Andrea Perego, Ph.D.
Scientific / Technical Project Officer
European Commission DG JRC
Institute for Environment & Sustainability
Unit H06 - Digital Earth & Reference Data
Via E. Fermi, 2749 - TP 262
21027 Ispra VA, Italy

https://ec.europa.eu/jrc/