Re: The last Best Practices requirement

Hello Alejandro,

I think it would be good to know if reusability of the data on the* "space
or object that data is being positioned within / upon"* is important here,
and if it is desirable to able to be precise about the relative location.

If the Linkability
<http://w3c.github.io/sdw/UseCases/SDWUseCasesAndRequirements.html#Linkability>
 and Spatial operators
<http://w3c.github.io/sdw/UseCases/SDWUseCasesAndRequirements.html#SpatialOperators>
requirements
where met I could say: *"I am currently inside the train that left
Amsterdam Central Station at 04:15"*. The "inside" part requires
standardisation of spatial relations and making a reference to the data
describing the train would be made possible by the linkability requirement. At
first glance, I thought that is the kind of thing that is described by the
requirement.

Now if it is desirable that other data sources (other people) can use the
same reference, something more may be needed, like specifying that the data
about the train can be used as a reference system, or putting the data
about the train in a collection of valid references for location (a
registry).

Another requirement could be to be able to be precise or quantitative about
the location relative to the *"space or object that data is being
positioned within / upon"*. In the train example, it could be desirable to
be able to specify wagon number and seat number. In that case, there is a
need for a definition of how the numbers that describe the location should
be interpreted (like in a formal description of a geographical coordinate
reference system). That would overlap with the BP requirement in column K
of the spreadsheet
<https://docs.google.com/spreadsheets/d/1PSnpJYQDgsdgZgPJEfUU0EhVfgFFYGc1WL4xUX9Dunk>
(which has not yet been carried over to the UCR document, by the way):*
"There should be a standard for publishing data about coordinate reference
systems  (CRS) - Not only geographical reference systems."*, but it is
taking it a step further because I don't think things like wagon numbers or
seat number would count as coordinates.

We could rephrase that requirement to *"There should be a standard for
publishing data about numerical reference systems - Not only geographical
reference systems and not only coordinate reference systems"*? Or is that
going too far (if a reference system is always a coordinate reference
system it would keep standardising reference systems simpler) and/or not
really demanded by a use case? At the moment I can't think of a use case
that requires numerical positioning by other means than coordinates.

Regards,
Frans









2015-04-30 13:40 GMT+02:00 Alejandro Llaves <allaves@fi.upm.es>:

> Hi Frans,
>
> this should be covered by the requirement CRS definition
> <http://w3c.github.io/sdw/UseCases/SDWUseCasesAndRequirements.html#CRSDefinition>
> in the case of geographic data, as Peter suggested. I don't think that
> Linkability
> <http://w3c.github.io/sdw/UseCases/SDWUseCasesAndRequirements.html#Linkability>
> and Spatial operators
> <http://w3c.github.io/sdw/UseCases/SDWUseCasesAndRequirements.html#SpatialOperators>
> requirements cover the definition of proper platial/placial reference
> systems. So, I would either adapt the CRS definition requirement to cover
> different spatial data reference systems OR create a new requirement for
> the type of scenario you describe.
>
> Cheers,
> Alejandro
>
> On 30 April 2015 at 08:37, Frans Knibbe <frans.knibbe@geodan.nl> wrote:
>
>> Hi Peter,
>>
>> Yes the datum does this, but only for geographical data. This working
>> group is about spatial data, of which geographical data are a subset. For
>> example, there could be data saying "I am in seat 7 of row 3 in auditorium
>> 4 of the Luxor Theatre". That is spatial data, but it does not use a
>> geographical reference system.
>>
>> Regards,
>> Frans
>>
>>
>> 2015-04-29 17:40 GMT+02:00 Peter Baumann <p.baumann@jacobs-university.de>
>> :
>>
>>>  Hi Frans,
>>>
>>> isn't this exactly the definition of a coordinate reference system
>>> anyway? The datum does this AFAICS.
>>>
>>> -Peter
>>>
>>>
>>> On 04/29/15 17:03, Frans Knibbe wrote:
>>>
>>> Hello Alejandro,
>>>
>>>  I am now looking at the last requirement on the Best Practices tab of
>>> the spreadsheet
>>> <https://docs.google.com/spreadsheets/d/1PSnpJYQDgsdgZgPJEfUU0EhVfgFFYGc1WL4xUX9Dunk/edit?usp=sharing>.
>>> It says:
>>> *"Requires a reference to not just a coordinate reference system but
>>> also an global reference to the space or object that data is being
>>> positioned within / upon"*
>>>
>>>  I wonder if this requirement is not already covered by the Linkabilty
>>> <http://w3c.github.io/sdw/UseCases/SDWUseCasesAndRequirements.html#Linkability>
>>> and Spatial Operators
>>> <http://w3c.github.io/sdw/UseCases/SDWUseCasesAndRequirements.html#SpatialOperators> requirements.
>>> If that is the case perhaps we won't need this as a separate requirement.
>>>
>>>  Greetings,
>>> Frans
>>>
>>>  --
>>>  Frans Knibbe
>>>  Geodan
>>> President Kennedylaan 1
>>> 1079 MB Amsterdam (NL)
>>>
>>>  T +31 (0)20 - 5711 347
>>> E frans.knibbe@geodan.nl
>>> www.geodan.nl
>>> disclaimer <http://www.geodan.nl/disclaimer>
>>>
>>>
>>> --
>>> Dr. Peter Baumann
>>>  - Professor of Computer Science, Jacobs University Bremen
>>>    www.faculty.jacobs-university.de/pbaumann
>>>    mail: p.baumann@jacobs-university.de
>>>    tel: +49-421-200-3178, fax: +49-421-200-493178
>>>  - Executive Director, rasdaman GmbH Bremen (HRB 26793)
>>>    www.rasdaman.com, mail: baumann@rasdaman.com
>>>    tel: 0800-rasdaman, fax: 0800-rasdafax, mobile: +49-173-5837882
>>> "Si forte in alienas manus oberraverit hec peregrina epistola incertis ventis dimissa, sed Deo commendata, precamur ut ei reddatur cui soli destinata, nec preripiat quisquam non sibi parata." (mail disclaimer, AD 1083)
>>>
>>>
>>>
>>>
>>
>>
>> --
>> Frans Knibbe
>> Geodan
>> President Kennedylaan 1
>> 1079 MB Amsterdam (NL)
>>
>> T +31 (0)20 - 5711 347
>> E frans.knibbe@geodan.nl
>> www.geodan.nl
>> disclaimer <http://www.geodan.nl/disclaimer>
>>
>>
>
>
> --
> Alejandro Llaves
>
> Ontology Engineering Group (OEG)
>
> Artificial Intelligence Department
>
> Universidad Politécnica de Madrid
>
> Avda. Montepríncipe s/n
>
> Boadilla del Monte, 28660 Madrid, Spain
>
>
> http://www.oeg-upm.net/index.php/phd/325-allaves
>
>
> allaves@fi.upm.es
>



-- 
Frans Knibbe
Geodan
President Kennedylaan 1
1079 MB Amsterdam (NL)

T +31 (0)20 - 5711 347
E frans.knibbe@geodan.nl
www.geodan.nl
disclaimer <http://www.geodan.nl/disclaimer>