************************************************************************ IERS Message No. 216 November 20, 2012 ************************************************************************ ITRS Combination Center at DGFI Dear Colleagues, This message is to inform you about a new publication of the ITRS Combination Centre at DGFI. The paper "The 2008 DGFI realization of the ITRS: DTRF2008" by M. Seitz, D. Angermann, M. Blossfeld, H. Drewes, M. Gerstl is now published in Volume 86 Number 12 of Journal of Geodesy, DOI: 10.1007/s00190-012-0567-2. The paper is also available online on the webpage of Springer http://link.springer.com/article/10.1007/s00190-012-0567-2 (please note that until November 30 all papers in Journal of Geodesy are accessible free of charge). The paper describes the computation of the ITRS realization 2008 at DGFI in detail. It starts from the very beginning: the analysis and comparison of input data in order to assess their consistency and qualification to contribute to an ITRS realization. The paper continues with the description of the computation strategy which is based on the combination of constraint-free (regarding the parameters of the geodetic datum) normal equations and discusses all the interim and final results. The fact that besides station coordinates also EOP are available as parameters common to all techniques is exploited by using the pole coordinates for local tie validation and by solving combined EOP series consistently with the DTRF2008, so that the EOP combination acts as an additional global tie. Finally, an accuracy assessment of ITRF solutions was performed by comparing the DTRF2008, the ITRF2008 and the ITRF2005. The final chapter "Discussion and conclusions" provides a list of recommendations for further ITRS realizations. Best regards, Manuela Seitz ************************************************************************ IERS Messages are edited and distributed by the IERS Central Bureau. If not stated otherwise, the IERS is only the distributor of the message and is not responsible for its content. To submit texts for distribution and to subscribe or unsubscribe, please write to . Archives: http://www.iers.org/Messages/ ************************************************************************