***************************************************************************
        Gazette IERS Gazette IERS Gazette IERS Gazette IERS Gazette
                                      _____________________________________
        No 12, 29 January 1997       /
____________________________________/              Contact: iers@obspm.fr
                                       ftp: hpvlbi.obspm.fr (145.238.100.7)
                      WWW: ftp://hpvlbi.obspm.fr/iers/ierscb.html
***************************************************************************

        Title:  The evolution of IERS 
        Author: Extended IERS Directing Board
        
   The IERS Directing Board started to work on the implementation of the 
1996 IERS Workshop Recommendations. It held two meetings, immediately after 
the Workshop in October 1996, and in December 1996. The major aspects of the 
foreseen evolution are as follows. Some are motivated by the IERS Workshop 
Recommendations, others are part of the normal evolution of IERS.

   - Maintaining the International Celestial Reference Frame (ICRF) based 
     on VLBI-derived directions of extragalactic radio sources, and of the 
     tie of the Hipparcos galactic reference frame, as will be recommended 
     by the IAU Working Group on Reference Frames to the 1997 IAU General 
     Assembly. This activity should be performed in concert with an IAU 
     Working Group on reference frames.

   - Contributing to the monitoring of the tie of the Solar System reference 
     frame to the ICRS.

   - Monitoring the global geophysical fluids that influence both the ground
     measurements and the Earth's rotation, an extension of the current 
     activity on atmospheric data. A Call for Proposals for setting up this
     activity in IERS will be sent out in February 1997.

   - Monitoring the motion of the Earth's centre of gravity. An Analysis 
     Campaign for better understanding this phenomenon and the capabilities 
     of the various satellite-tracking techniques is started (see IERS
     Gazette No 10, 2 January 1997).

   - Fostering the provision of global vertical terrestrial references and
     of global horizontal references for the monitoring of crustal 
     deformations, in close cooperation with the International Association 
     of Geodesy.

   - Improving the internal consistency of the IERS EOP series with the ITRF
     and ICRF. An analysis campaign to better understand this is in preparation.
       
   - Promoting global combination of observations from the various techniques
     to derive IERS products. Plans for this activity are currently developed.

   - Enhancing the role of Coordinators and adding new Coordinators for 
     general themes of importance to IERS (e.g. the above-mentioned 
     monitoring of global geophysical fluids).

   - Maintaining interaction with Working Groups set up by IAU, IAG and IUGG on 
     topics relevant to IERS missions. 

   - Creating an IERS Conventions Editorial Board.
   
   - Extending formally the Directing Board membership to better represent
     all components of IERS activities.

   - Polling the IERS distribution lists to check the various types of users 
     and their specific requirements (see IERS Gazette No 11, 21 January 1997).

   The Directing Board will meet again in Vienna in the week 21-25 April 1997, 
in parallel with the European Geophysical Society General Assembly. They will 
review the progress of ongoing changes and prepare the presentations to be 
made at the IAU General Assembly in August 1997 in Kyoto and at the IAG 
Scientific Meeting in September 1997 in Rio de Janeiro.

   Considering this heavy meeting schedule for 1997, the Directing Board 
decided to organize the next IERS Workshop in 1998, when effects of the 
currently planned changes will be visible and can be discussed again.

   The whole endeavour of reviewing IERS and making it evolve owes much to 
the dedication of the scientists that accepted to work actively on its 
evaluation. The IERS Directing Board is most thankful to these colleagues 
for their strong contributions.