RFC2 period for Meas/Coors model start son Oct 26

[Laurent Michel]

Dear VO,

We are pleased to announce the start of the second RFC period for both Meas and Coord models.
This review sequence will run over 6 weeks starting from  Oct 26.

RFC pages:
----------
    Meas: https://wiki.ivoa.net/twiki/bin/view/IVOA/MeasRFC2
  Coords: https://wiki.ivoa.net/twiki/bin/view/IVOA/CoordsRFC2


Following the discussions that took place on the list last weeks, we think it is useful to recall the reasons for which we 
engage this second phase:

Rationale for a second RFC round:
--------------------------------

- Many comments have been collected after RFC #1. Some of them just required text
   improvements but some others implied significant model changes, especially for Coords.

- A global RFC answer has been sent to WG mailing list in February 2020:
   http://mail.ivoa.net/pipermail/dm/2020-February/005975.html

- These data models should support the description of datasets and DAL responses,
   by defining fundamental elements which are commonly used in many contexts.
   The intent is that they be imported as components in these more complex models
   so that they all build from the same basis, thereby enhancing interoperability.

- They should NOT be expected to fully support any use-cases outside of the described set.
   For example, they cannot currently support the complex error types found in various Catalogs.
   These use-cases are to be considered in future updates to the models.

- Measurements cannot be used without Coords because the latest is imported by Measurements
   but Coords can be used in some other contexts e.g. Transform.

- The nature of the changes in Coords, that impacts Measurements thus, led the TCG to decided
   on 2020-10-8 a second RFC round for both models.

Regards

LM JS

-- 
jesuischarlie/Tunis/Paris/Bruxelles/Berlin

Laurent Michel
SSC XMM-Newton
Tél : +33 (0)3 68 85 24 37
Fax : +33 (0)3 )3 68 85 24 32
Université de Strasbourg <http://www.unistra.fr>
Observatoire Astronomique
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