Characterization data model

[Francois Bonnarel]

Dear all, 

Just to inform everybody that a new version of UML schema for Characterization 
and of the

xml schema are now available taking into accounts the results of discussion we 
(ML+FB) 

had with Alberto Micol, Brian Thomas and Arnold Rots.

(http://alinda.u-strasbg.fr/Model/Characterisation/   DM and xhar0505.xsd)



The general frame has been modified in the following way:

- Levels of description have been added in Resolution and Sampling in order to 
get a parallel

path there and in Coverage, and take into account the internal variation of 
these properties. But the

 Names and even the internal structure of these levels are different in 
Resolution/sampling and in Coverage. 

- The Accuracy (Stat err) property structured like Resolution and Sampling has 
been added, because it

 seems to be really usefull to characterize the Obserbvation data, don't fit 
elsewhere in the model and was

 actually allready included in "characterization" by the SSA proposal.

The xml schema has been heavily revised to be considered as a part of a 
general set of VO Dm Schema

reusing Quantity and STC definitions. Actually we used the schemata 
implementation proposed

by Brian Thomas for VO Catalog (http://archive.astro.edu/VOCatalogTest/). 
Brian's proposal rewrites most of

STC stuff as Quantities. So that was easier for us to define our main 
Characterization ComplexTypes

as CompositeQuantities and to reuse all the STC types we need for our basic 
Types this way. The basic idea

we took from Brian is to consider Charcterization types as "restrictions" of 
CompositeQuantties instead of

definig Extensions, or to simply use elements of Q or STC type inside our type 
definitions sequences.

Brian , if you could have a look to this and comment it could be usefull for 
our session of Thursday.

Mireille Louys and François