WD-DataLink-1.0

[Laurent Michel]

Hello,

We must keep in mind that Datalink is a protocol enable to operate any remote service whether using VO protocols or not.
For this reason, I believe that the project of achieving a  dictionary of links serving all astrophysical fields is destined to 
fail. There will always be some peculiar cases carrying concepts which are not in that dictionary. Indeed, the ability of a 
client to do appropriate processing strongly depends on this vocabulary.
To sort out this contradiction we are supporting the idea of using some hierarchical construction for this vocabulary where a 
path element refines its predecessor. With this concept, the first element (mandatory) would have to match the list set in 4.6.

PROPOSAL
========
Our first idea was to use the same construction as for UCDs, but another alternative, avoiding any confusion with UCDs, could be 
to use the grammar of the Mime type parameters (A nice example is given in 3.1)

Example: The calibration bias would be expressed as "calibration;content=bias" where "content=bias" remains optional.
The basic concept "calibration" would be enough for most of the clients (another similitude with Mime types)

Using this mechanism would allow to go ahead with the V1 of the protocol. The possible values of the content field would remain 
open or just restricted by list of reserved words.

Bye
LM




Le 14/11/2013 11:51, Louys Mireille a écrit :
> Hi Arnold , Hi all ,
>
> The goal here is not to classify things again in a general data model and force a categorisation of data products, but on the
> contrary ,
> to record some terms that will be meaningful. Applications could follow the links between datasets and touch the attached data /
> metadata useful for their context/ usage.
>
> if the radio community uses "Beam" instead of PSF, the usual "beam" term would be meaningful and understandable for the context of
> radio oriented applications.
> the idea was to relax the constraints we had in the data modeling and offer more flexibility.
>
> Best wishes,
> Mireille
>
>
> Le 12/11/2013 20:30, Arnold Rots a écrit :
>> I think this list needs some serious consideration,
>> particularly to make sure that the terms have
>> general application and that coverage is complete.
>>
>> For instance, a radio beam image is no different
>> from a PSF. And what is the relation between an
>> error map and a noise map? How does that relate
>> to a sensitivity map. What about an exposure map?
>> And I thought it peculiar that the first item under
>> ancillary contains miscellaneous calibration data;
>> why isn't that under calibration? Also, the set of
>> calibration data types seems rather limited.
>>
>> Let's not rush this list.
>>
>> Cheers,
>>
>>   - Arnold
>>
>> -------------------------------------------------------------------------------------------------------------
>> Arnold H. Rots Chandra X-ray Science Center
>> Smithsonian Astrophysical Observatory tel:  +1 617 496 7701
>> 60 Garden Street, MS 67 fax:  +1 617 495 7356
>> Cambridge, MA 02138 arots at cfa.harvard.edu <mailto:arots at cfa.harvard.edu>
>> USA http://hea-www.harvard.edu/~arots/ <http://hea-www.harvard.edu/%7Earots/>
>> --------------------------------------------------------------------------------------------------------------
>>
>>
>>
>> On Tue, Nov 12, 2013 at 11:25 AM, François Bonnarel <francois.bonnarel at astro.unistra.fr
>> <mailto:francois.bonnarel at astro.unistra.fr>> wrote:
>>
>>     Hi all,
>>         The attached file  gives a proposal for extended values for the semantics column described in 4.6.
>>         We were considering the fact that the original list could be too short for our various use cases.
>>         Semantics column is supposed to give the role  of the linked resource with respect to the original dataset
>>     Best regards
>>     Mireille Louys, Laurent Michel, François Bonnarel
>>
>
> --
> Mireille Louys	, Maître de conférences
> Centre de Données astrophysiques de  	Icube & Télécom Physique Strasbourg				Pôle API
> Observatoire de Strasbourg 		300, boulevard Sébastien Brant
> 11, Rue de l'Université			CS 10413
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> tel : 03 68 85 24 34
>

-- 

---- Laurent MICHEL              Tel  (33 0) 3 68 85 24 37
      Observatoire de Strasbourg  Fax  (33 0) 3 68 85 24 32
      11 Rue de l'Universite      Mail laurent.michel at astro.unistra.fr
      67000 Strasbourg (France)   Web  http://astro.u-strasbg.fr/~michel
---