Short report on the IERS Workshop
          "Combination research and global geophysical fluids"
                    held in Munich, 18-21/11/2002

             Martine Feissel-Vernier et Jean-Jacques Valette

About 90 participants were registered in total. MFV and JJV were the two
"DORIS" participants. We had been invited to contribute to topic 4. listed
hereafter. JJV presented a poster on "IDS analysis campaign: current
combination activities." (Valette, Soudarin, Altamimi). MFV and P. Willis
are coauthors of the topic position paper, for the DORIS section.

List of sessions in the "combinaison" part of the Workshop (two days)

1. Combination of station coordinates, velocities, local ties, datum
   definition, non-linear motion, ...
   (Altamimi / Boucher / Drewes / Ferland )
2. Celestial reference frame issues
   (Souchay / Ma)
3. Combination / comparison of EOPs (xp, yp, UT1/LOD, nutation),
   subdaily EOPs, impact of IAU Resolutions
   (Gambis / Vondrak)
4. EOP Alignment Campaign, IGS / IVS / ILRS combinations, systematic
   errors (Nothnagel / Dill)
5. Conventions and models for a rigorous combination, consistency aspects,
   systematic errors. (McCarthy / Petit)
6. Aspects of a rigorous combination, combination of several parameter
   types, different combination levels (Ray / Zhu)
7. SINEX Combination Campaign  (Angermann / Thaller / Rothacher)

Extract of IERS Workshop recommendations interesting DORIS

There was a large number of recommendations. Those that are
potentially impacting DORIS may be summarized as follows.

- The final results for the EOP Alignment Campaign and for the Sinex 
  Combination Campaign will be presented at the EGS-AGU meeting in April
  2003. For the Sinex Combination Campaign, more discussion is needed 
  with the data contributors. Solutions may have to be submitted again.

- Concerning all technique centers, i.e. IVS, IGS, ILRS, IDS:
  . more detailed documentation is requested on the standards, models and
    analysis strategies used,
  . non-linear motion of stations should be taken into account in TRF
    analyses. The times of breaks (with geophysical or human source) in
    the stations should be maintained by the Technique Centers.

- Concerning DORIS/IDS:
  . make available a unified DORIS solution for the terrestrial reference
    frame and the EOPs,
  . consider increasing the number of stations colocated with SLR and/or 


- IERS concerning the data analyses should form a part of the agenda at
  the February Workshop (at IGN/LAREG, Marne la Vallee near Paris, 20-21
  February 2003).

- It was clear from this Workshop that the IERS is undergoing a new start.
  This makes it particularly timely to create the IDS now.