Submitted Abstract
The geocentric positions of thousands of permanent geodetic stations distributed over the Earth’s surface and their motions can now be determined with an accuracy of a few millimetres and 1 mm/yr respectively. This precision is only possible as a result of the tremendous developments in space geodetic hardware, international investment and cooperation in network deployments, and formulation of high-quality data processing algorithms and background models over the last three to four decades. Continuous geodetic observations are fundamental for many Earth science applications. The observations are also used to understand geodynamic processes at the global scale such as climate-driven changes in the hydrosphere, the cryosphere, the ocean and the atmosphere. Observations at the local or regional level are used to understand tectonic motion, local subsidence, earthquake deformation, reservoir depletion, etc. One of the most demanding and societally important applications of these continuous observations is to monitor mean sea level change and its variability in space and time, given the ramifications of sea level rise due to global warming. All these science applications depend critically on the availability and accuracy of a global and accessible Terrestrial Reference Frame (TRF). A TRF is also required to ensure the integrity and inter-operability of Global Satellite Navigation Systems (GNSS, such as GPS, GLONASS, Galileo, and BeiDou). The history of ITRF goes back to 1984. Since then, successive updates have been published, each surpassing its predecessor in precision. The community is currently preparing for the next ITRF, ITRF2013. After that, it might be necessary for ITRF to evolve differently if it is to capture the complete dynamics of the Earth’s surficial variations with the full accuracy of modern geodetic data. Now is the time the community to step back, review the needs of regional and global reference frames, and set new challenges for the development of perhaps something quite different for the future. The symposium program is intended to draw international experts from NA, SA, Europe, Asia, Australia, to Luxembourg with the goal of debating and charting approaches to address such questions as:•Theory: Are present reference frame theory and concepts adequate? Is a new framework required to address the mismatch between long-term linear theoretical frames and the reality of constantly non-linear station motion?•Measurement Techniques: How can the strengths and weaknesses of current geodetic technologies be better meshed to improve the ITRF? What are the leading geophysical model limitations and how can they be improved? •Regional Reference Frames: Is there a future for sub-global reference frames of high accuracy in the age of GNSS? If the main justification for regional frames is to remove large-scale tectonic effects, how well can this really be done? •Tieing the ITRF to the International Celestial Reference Frame (ICRF): Can the value of Earth orientation parameters (EOPs) as proxies for Earth system mass variation be improved (e.g., better accuracy, higher temporal resolution)? How can the current ICRF implementation be made consistent with the ITRF and EOPs and how can improved accuracy be achieved? •Science Applications: What are the major geoscience questions that cannot currently be addressed by the geodetic observing systems? What is the required accuracy of the geodetic products needed? What is the best way to integrate geodetic and gravimetric systems?•Georeferencing for Commercial Applications: Are emerging commercial geodetic applications (e.g., GIS) approaching high-accuracy requirements? How can the basic infrastructure, the observing systems, that are funded by national research bodies be sustained, especially as commercial applications grow in importance?