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IERS Message No. 80                                     January 11, 2006
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ITRS Combination Center at DGFI


Dear Colleagues,

This message is to inform you about a publication of the ITRS 
Combination Center at DGFI. The documentation presents the major 
components and the combination methodology of the ITRS CC as well as the
mathematical background for the combination, which is based on the level
of unconstrained normal equations. The second part focusses on the 
computation of a terrestrial reference frame realization 2003 based on 
multi-year VLBI, SLR, GPS and DORIS solutions with station positions and
velocities. A comparison of the DGFI solution with ITRF2000 can be 
considered as a first "quasi-independent" quality control and TRF 
accuracy evaluation. Finally the current status regarding TRF 
computations, remaining deficiencies and recommendations for the future
are addressed.

The title of the publication is:

     ITRS Combination Center at DGFI: A Terrestrial Reference
     Frame Realization 2003

     Authors: D. Angermann, H. Drewes, M. Krügel, B. Meisel, M. Gerstl,
                     R. Kelm, H. Müller, W. Seemüller, V. Tesmer

The document has been published in "Deutsche Geodätische Kommission,
Reihe B, No. 313, München, 2004 (ISBN 3769685938)".

An electronic version of this publication is available
at <http://dgk.badw.de/index.php?id=10>.

Regards and best wishes for the year 2006

Detlef Angermann

Deutsches Geodätisches Forschungsinstitut (DGFI)
Marstallplatz 8, 80539 München, Germany


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