Characterisation data model version 2.0 draft

[François Bonnarel]

Dear all,

       I would like to announce the very first release of the 
Characterisation version 2 Working draft...

       This effort started immediatly after the release of version 1.0 
of the model more than 3 years ago, because
some extended features (level 4 characterisation, complex data) had been 
intentionnaly postponed for a future version...
       Since 2008, we also encountered data providers and other working 
group feedback on version 1. From 2009
on, the ObsTap effort led to a couple of additional slight changes in 
the model...
       This effort had been mainly slowed down for the reason that most 
participants were concentrated on this
Obstap effort but nonetheless it was regularly reported at each Interop 
from May 2008 to May 2011
(see eg My napoli presentation: 
http://www.ivoa.net/internal/IVOA/InteropMay2011DM/CharVersion2.0.pdf)
        Beside the obstap-motivated changes the new version allows 
taking into account Composed datasets,
Polarization and discrete-valued axes,  Redshift axes, sensitivity maps, 
psf, resolution variation maps, etc...
       A prototyped version of characterisation 2 metadata service has 
been used by Igor in his spectrum "best fit"
service presented in Nara and Napoli.
       Xml schema is actually ready but will be posted only in August on 
this list...
       The draft version is there: 
http://www.ivoa.net/internal/IVOA/CharacterisationDataModel/NewChar2.pdf
  There is still lot of editorial mistakes probably, but it's now time 
to discuss the ideas more widely...
       The draft contains the description of an Extended package which 
is probably usefull for IVOA outside
the context of Char 2 (within povenance and Data Link as I wrote in my 
email on this topic yesterday).
      We may have to decide to make a dedicated document for this 
extended access package...

Best regards
François