Minutes of the meeting.


  • Aim of the working group
  • 2006 priorities (use cases : image and spectrum)
  • Other use cases
  • Next IVOA Interop meeting
  • ...


  • Image use case status, Eric Slézak
    - observation data -> image available for a treatment (orientation on the Sky, distortion, ...)
    - sampling, ...
    - a part of the process is done manually, must be resolved before workflow in production phase
    - workflow quality depends on upstream quality
    - noise correlation
    - do not consider that the instrumental characteristics are not variable
    - first trimester : workflow finished for the China Interop meeting
    - Terapix tools (p.f. estimation, deconvolution, ...)
    - correct propagation of uncertainties
    - noise correlation
    Philippe : it is a problem of Data Model, not taken into account by the DM
    - visualisation tools
    Eric would like that the LSIIT tools available on line (especially Mathieu Petremand work)
    - new instruments : radio = image producer
    - workflow available for the China interop meeting
    - better quality of the workflow processing : backward, etc.
    - see the steps, the loops, ... -> classification of the sources
    - visualisation tools very important (date cubes, ...)
    - cf. slides

  • Spectrum Use Case, Philippe Prugniel
    - many things are not taken into account by IVOA : for example the noise
    - simple bricks to use quickly
    - cf. last meeting in Paris of a group of spectrum producers and users
    - common bricks in image and spectrum domains
    - many people are ready to develop tools and services
    - interconnection spectrum/tools -> near from the workflow aspects
    - implementation to make science : it is possible to use simple workflows which are not necessary using VO tools
    - so, basic bricks to define : sampling, cross corelation, ...
    Eric : example of which could be pertinent to transmit between image and spectrum
    -> image of a galaxy with a star over
    many programs are available but it would be nice to show workflows involving them
    - cf. slides

  • Research of objects in archives use case, Jérôme Berthier
    - work in progress : DENIS (index of color, astrometry), DFBS (spectrum)
    - ongoing work : ESO-R, POSS
    - DENIS represents 880740 images for ~90 days processing
    - workflow : (input/output) object list, aim -> create boxes with the correlators to use them in the workflows
    - error management, process duration
    - interactions, master/slave relation, input/output
    - langage and workflow bricks
    - cf. slides

New Use cases in other domains

  • Research of objects in archives use case, Franck Le Petit
    - connecting software codes together is not easy : output data format -> data model problem, UCD
    - quantity definition not the same for the different codes
    - problems due to binary format : results are written is a big binary file (possible problem like little/big endian) -> a solution could be to read the binary on the server where it has been created but it is often stored on an another server, put a header in the file to describe the format, ...
    - conclusion : code and theoretical databases coupling, asynchronous computing, change of code to study physical results, observation comparison
    - cf. slides

  • ... proposed by Loic Lechevallier
    - stop point important during the execution
    - full description will be available soon

Overview of different languages :

  • cf. André's presentation

Short resume of the final discussion :

  • Meeting in April to prepare the May China Interop

  • Use cases to explain in the frame of the IVOA Theory IG
    - Image workflow
    - link with patterns
    - YAWL patterns ?
    - ESO Reflex to explore (meeting in March with R. Hook)

  • IVOA Theory :
    - research results : it is important to store the history, it must be possible for a referee to controle the workflow described in an article -> so it must be easy to replay a workflow (user friendly tool, portable workflow defintion, etc. )

  • IVOA Application WG
    - tools to show

  • IVOA Data Model WG : interfacing with this group

  • common bricks between the different use caes : probably not for the next Interop
    - but could be discussed (cf. SNAP) on the OV Theory mailing list
    - example : resampling and coordinate extraction, not the same algorithm but common semantic

  • definition of a desirable list of bricks needed in the future (including one concerning the noise)

  • lot of algorithms could be presented at IVOA (in image domain for example)

  • mailing list
Topic revision: r1 - 2008-10-10 - TWikiAdminUser
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