[IGSMAIL-5664]: ITRF session at EGU2008

[Zuheir Altamimi]

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IGS Electronic Mail      26 Nov 05:53:37 PST 2007      Message Number 5664
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Author: Zuheir Altamimi & Jim Ray

    EGU General Assembly -- Vienna, Austria, 13-18 April 2008
              http://meetings.copernicus.org/egu2008/

Dear Colleagues,

The General Assembly of the European Geosciences Union will be
held in Vienna, Austria, 13-18 April 2008. We draw your attention
in particular to session "G4 - The impact of technique errors on
reference frame accuracy and stability":

Experiences with the 2005 version of the International Terrestrial
Reference Frame (ITRF2005) have underscored once again significant
differences among the contributing observing techniques and their
importance in limiting the accuracy and stability of the combined
frame. Those differences related to variations in intrinsic
sensitivity to certain parameters (such as the Earth's geocenter)
enable the ITRF to have the potential of improved accuracy over
any single technique. However, other differences, such as related
to choices in analysis models, can degrade the global combination.
Systematic errors in techniques, both of known and unknown causes,
also degrade the ITRF accuracy and can lead to long-term
instabilities and other weaknesses.

Given the current high precisions achieved by all the space
geodetic observing methods, it is vital to improve our
understanding of the specific errors of each and their effects on
ITRF. All potential error types must be considered including
differences in data modeling. It is equally important to develop
techniques to mitigate error effects whenever possible.

As always, it continues to be critically important to understand
the physical relationships between the reference points of
co-located systems at a highly detailed and accurate level, the
so-called "site tie problem". While much has been said about this
topic, the progress for ITRF realizations has been disappointing
and this continues to be a limiting error in the overall
combination.

Contributed papers in all aspects of these inter-connected
problems are requested. Work that illuminates characteristics of
individual techniques or their combinations is sought. Approaches
that either attenuate technique-specific errors or help understand
their causes are especially needed.


Important Dates:

14 January 2008:   Deadline for receipt of abstracts at

http://www.cosis.net/members/meetings/programme/view.php?m_id=49&p_id=325

31 March 2008:     Deadline for pre-registration & hotel booking

Please consider submitting a paper for this symposium or contact
us directly if you have any questions.

Sincerely,

Zuheir Altamimi, altamimi at ensg.ign.fr ENSG/LAREG, Institut
Geographique National

Jim Ray, jimr at ngs.noaa.gov Geosciences Research Division, National
Geodetic Survey

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Zuheir Altamimi                           Email : altamimi at ensg.ign.fr
Institut Geographique National            Phone : 33 1 64 15 32 55
ENSG/LAREG                                FAX   : 33 1 64 15 32 53
6-8 Avenue Blaise Pascal
77455 Champs-sur-Marne, FRANCE
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