RFC period for Characteristion DM has finished

[Francois Bonnarel]

Hello Pedro,

   Thank you for your comments. please find here a partial answer
already posted on the Char RFC page

Cheers
François

I am only answering About Observation Data model and let MireilleLouys adress the other points:

This datamodel effort has been frozen  since we decided to focus on the
characterization part,which became a model in itself. In the original 
view (see Note ..., 2004) Characterization was a class of the overall 
Observation data Model.
Other classes were Data, Curation, Provenance, DataID, Target etc ...
But I think it is now time to go back it. there is some demand for
that.

Actually a complete Observation datamodel already exists, but specific for
1D spectra: its the spectrum datamodel
and its relationship to Overall Characterization is rather clear I think:
the Char class in Spectrum datamodel is a specific implementation of overall
char.

For an overall Observation Data Model we will have to revisit the Data,
Curation, DataID, Target as in spectrum and check if they are general enough.
My personnal opinion is that Data is not and that Curation, DataID, Target
probably are. (But do we really need a data class for Images, 3D data , etc ??? 
We have FITS which is working well for data in that case ...)

So  we see that for an overall Observation datamodel we have to split 
the effort in two parts : 
                    - Data class on one side, (which may keep simple
or ethen neglected ?). 
                    - Metadata classes on the other side.

For all the metadata classes the Spectrum model is a good starter except
that Provenance is missing. There is a lot of demand in various communities
for modelizing the instrumental and moreover softawre Provenance of the 
datasets. So I think the next step as we already stated during the first DM 
session in Beijing (see my talk there and Jonathan's conclusions) will be to
focus on Provenance...

Now the last point you adress is a vocabulary one. Some people may want to call
all metadata "Characterization" (actually some astronomers outside our
IVOA community allready do when they specify their needs - see the discussions
during spectroscopic workshop last March at your site) including Curation 
and Provenance ... It may be the final IVOA choice, but in that case 
we have to find a new class name for what is presently called Characterization
which is this part of metadata dealing with the description of the dataset in
the data parameter space....
My personal opinion is that I don't see any good reason to change:

    so the future ObservationDM Map could be:

                ObservationDM

        Data                  Metadata

                             ObsId, curation, Char, Provenance , etc ...

=====================================================================
Francois   Bonnarel               Observatoire Astronomique de Strasbourg
CDS (Centre de donnees          11, rue de l'Universite
astronomiques de Strasbourg)    F--67000 Strasbourg (France)

Tel: +33-(0)3 90 24 24 11       WWW: http://cdsweb.u-strasbg.fr/people/fb.html
Fax: +33-(0)3 90 24 24 25       E-mail: bonnarel at astro.u-strasbg.fr
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