HR: 0800h
AN: G41C-0372    [Abstracts]
TI: Description of Earth Orientation Parameters Using an Approach Based on Stochastic Processes
AU: Sillard, P
EM: patrick.sillard@insee.fr
AF: CREST/INSEE, 18/ Boulvard A. Pinard, Paris, 75014 France
AU: * Altamimi, Z
EM: altamimi@ensg.ign.fr
AF: Institut Geographique National ENSG/LAREG, 6-8 Avenue Blaise Pascal, Champs-sur-Marne, 77455 France
AU: Gambis, D
EM: daniel.gambis@obspm.fr
AF: Observatoire de Paris, 61 Avenue de l'Observatoire, Paris, 75014 France
AB: The International Terrestrial Reference Frame (ITRF) is a key product for scientific users in the field of Geodesy, Astronomy and Geophysics. The last issue (namely ITRF2004) which will be available before the end of 2005 will be the opportunity to introduce Earth Orientation Parameters (EOPs) in addition to the set of station positions and velocities that was currently derived so far. EOP observations are treated in a consistent way with the terrestrial frame by the analysis centers of the various Space Geodesy techniques. Therefore, the intrinsic nature of these parameters is the same as the one of station coordinates. It becomes now classical to adopt a time-series description of station positions, an approach which is already adopted for EOPs. Nevertheless, EOPs are usually combined together with sets of stations coordinates for terrestrial frame computation as if they were not correlated in time, which is certainly not the case. The dynamic equations that connect one parameter at one epoch to the next one are investigated here with the prospective objective of introducing this information while combining sets of station coordinates and EOPs for ITRF computation. Although this link is of stochastic nature, it is however based on physical principles (such as variable components of Liouville equation due for example to atmospheric excitation). These physical principles are also investigated.
DE: 1229 Reference systems
DE: 1239 Earth rotation variations
SC: Geodesy [G]
MN: Fall Meeting 2005