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CHANGE IN THE PRODUCTS OF THE EOP-PC STARTING IN JANUARY 2003

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Beginning on 1 January 2003, IERS C04 makes available new products: dX and dY
related to the new IAU2002A Precession-Nutation theory IN ADDITION to the
current (dpsi,deps)_1980 according to the formulation:
1) dpsi_1980 = psi_obs - psi_IAU1980
   deps_1980 = eps_obs - eps_IAU1980
2) dX        = X_obs   - X_IAU2000A
   dY        = Y_obs   - Y_IAU2000A

Different yearly C04 files are available:
1) Current files maintaining (dpsi,deps)_1980 currently labelled:
    ..., eopc04.01, eopc04.02, eopc04.03, ...
2) New files containing dX and dY listed IN THE SAME FORMAT.
        eopc04_IAU2000.02, eopc04_IAU2000.03,...
        
The new files are available at the following Web/ftp sites:
- Web:
   http://hpiers.obspm.fr/eoppc/eop/eopc04/eopc04_IAU2000.02
   http://hpiers.obspm.fr/eoppc/eop/eopc04/eopc04_IAU2000.03 (January 2003)
- anonymous ftp:  hpiers.obspm.fr
   files : /eop-pc/eop/eopc04/eopc04_IAU2000.02
           /eop-pc/eop/eopc04/eopc04_IAU2000.03           

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We propose softwares for transforming from any representation to another one:
1)  UAI 1980 celestial pole offsets (dpsi,deps)_1980,
2)  UAI 2000 celestial pole offsets (dX,dY),
3)  UAI 2000 celestial pole offsets (dpsi,desp)_2000,
     according to the formulation:
     dpsi_2000 = psi_obs - psi_IAU2000A
     deps_2000 = eps_obs - eps_IAU2000A
These softwares are available in Fortran 77/90 package at the following
Web/ftp sites:
- Web page:
   http://hpiers.obspm.fr/eop-pc/models/models.html#software
   
   ftp://hpiers.obspm.fr/eop-pc/models/uai2000.package
   ftp://hpiers.obspm.fr/eop-pc/models/uai2000.package.readme

- anonymous ftp:  hpiers.obspm.fr
   files : /eop-pc/models/uai2000.package
           /eop-pc/models/uai2000.package.readme          
          
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BULLETIN B, giving EOPs with a two month delay, will be duplicated from
March 2003 onwards to give dX and dY in the new formulation IN ADDITION
to the current issue containing (dpsi,deps)_1980.

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We intend to maintain this duplication of C04 series and Bulletin B until
December 2005.

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Notice to VLBI Analysis centers:
We expect that the changes within the analysis softwares will be made
progressively. For the transition period, we are ready to process
any data, relative to the old or new models, as soon as the
descriptions of the nutation estimates and the reference model are CLEARLY 
indicated.

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