From jim.ray at noaa.gov Tue Dec 29 12:22:17 2009 From: jim.ray at noaa.gov (Jim.Ray) Date: Tue, 29 Dec 2009 15:22:17 -0500 Subject: [IGSMAIL-6050]: G3 session on reference frames at EGU2010 -- reminder Message-ID: <4B3A64F9.6020205@noaa.gov> ****************************************************************************** IGS Electronic Mail 29 Dec 12:22:48 PST 2009 Message Number 6050 ****************************************************************************** Author: Zuheir Altamimi & Jim Ray EGU General Assembly -- Vienna, Austria, 02 - 07 May 2010 http://meetings.copernicus.org/egu2010/ Dear Colleagues, The General Assembly of the European Geosciences Union will be held in Vienna, Austria, 02 - 07 May 2010. We draw your attention in particular to session "G3 - Non-linear Motions and Other Effects in Realizing Terrestrial Reference Frames As the quality of space geodetic positioning results continues to improve, our ability to detect small deviations from linear motion increases. Large-scale, regional, and local loading effects can contribute to such motions and space geodesy is proving useful to monitor such processes. But technique errors and other effects can also contribute to apparent non-linear motions, complicating the interpretation of geodetic time series. Analysis of GNSS time series is particularly difficult in many cases due to frequent equipment changes, not all of which are well documented. Handling these and other types of non-linear motions optimally in forming long-term reference frames, such as the International Terrestrial Reference Frame, is challenging. Various approaches have been proposed and discussed. Experiences with the recent ITRF2008 combination provide an opportunity to reconsider some of the issues involved using consistent, reprocessed time series that incorporate new analysis models and updated processing strategies. It is important to examine, among other things, how different approaches to handle non-linear motions affect the ITRF datum (origin, scale, and orientation). Papers are sought that study all aspects of these issues, including multi-techique combination methods, characterization and treatment of various systematic errors, datum specification, and future directions. Automated algorithms to detect discontinuities in position and velocity time series are particularly requested, as this has become a major complication in realizing GNSS reference frames. Any other reference frame-related issues specific to the individual observing techniques are also of interest to this session. 18 January 2010: Deadline for receipt of abstracts at http://meetings.copernicus.org/egu2010/abstract_management/how_to_submit_an_abstract.html Please consider submitting a paper for this session or contact us directly if you have any questions. Sincerely, Zuheir Altamimi, altamimi at ensg.ign.fr ENSG/LAREG, Institut Geographique National Jim Ray, jim.ray at noaa.gov Geosciences Research Division, National Geodetic Survey