Transform model - WD for review

[CresitelloDittmar, Mark]

All,

This is coming a bit later than originally planned, but is a much better
reviewed/vetted model that we are able to deliver.

At/After the College Park interop, a small group was formed to work a
project to evaluate/exercise the Transform model.
This group includes folks involved in:
  + AST library implementation
  + gWCS package implementation
  + AstroPy
Working with projects:
  + CXC
  + JCMT
  + JWST
  + LSST

The model described is compatible with these implementations (and wcslib),
and, as such, they can serve as reference implementations for the model.
There is a table on the twiki page
<https://wiki.ivoa.net/twiki/bin/view/IVOA/STC2#Implementations> which
maps, at a relatively high level, the model objects to the implementations.

Content-wise, the transform operations are largely unchanged from earlier
versions of the model, modulo some elements for more detailed control.
What has changed is the addition of elements to help manage/describe the
workflow of data through a Transform sequence in both the forward and
inverse directions.

The document can be found in volute: WD-Trans-1.0.pdf
<https://volute.g-vo.org/svn/trunk/projects/dm/STC/Trans/doc/WD-Trans-1.0.pdf>
And in the IVOA document repository: WCSTrans
<http://www.ivoa.net/documents/WCSTrans/20190412/index.html>

Mark
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.ivoa.net/pipermail/dm/attachments/20190423/f30ab754/attachment.html>