1. POD/Geoid splinter Wednesday March 14, 2007 Morning and Afternoon J.P. Berthias – J. Ries Ocean Topography Science Team Meeting - Hobart, Australia – March 2007

2. 2 POD after Venice … before Hobart ■POD plan was to be ready to start producing orbits with new standards by Fall 2006  “availability of ITRF2005 and time variable gravity model set the time table” ■ITRF2005 arrived … with difficulties  a lot of work went into its evaluation  new issues were raised ■reprocessing of early cycles with GDR-b standards  postponed the need for the “new” standards  opens the possibility to revise choices made in Venice

3. Ocean Topography Science Team Meeting - Hobart, Australia – March 2007 3 Goals for Hobart POD/geoid splinter ■Evaluate quality of GDR-b orbits ■Evaluate impact of ITRF2005 and adopt it as is or with modifications ■Review recent progress in Gravity and Geoid models with a focus on Time Variable Gravity ■Review contribution of orbit to the overall error budget ■Collect inputs on the Jason-3 orbit choice issue from the POD point of view

4. Ocean Topography Science Team Meeting - Hobart, Australia – March 2007 4 Splinter schedule ■Two part splinter  morning session during Splinter session 2  Wednesday morning from 9:30 to 12:30  afternoon session during Splinter session 3  Wednesday afternoon from 16:30 to 18:00  after poster session ■morning and afternoon sessions will be held in room TASMAN A

5. Ocean Topography Science Team Meeting - Hobart, Australia – March 2007 5 Morning session : POD ■09:30 - J.-P. Berthias - Introduction: Status of Pending Actions and Key Issues ■09:45 - L. Cerri - Jason-1 POD Reprocessing at CNES: Current Status and Further Developments ■10:00 - L. Cerri, J.-P. Berthias – Time Variable Gravity : Implementation Issues for Jason 1 ■10:15 - W. Bertiger - Precision Orbit Determination, Trade Studies and Improvements for Jason-1 with GPS ■10:30 – Break ■11:00 - F. Lemoine - Improvement of the Complete TOPEX and Jason Orbit Time Series: Current Status ■11:15 P. Bonnefond - Validation Activities for Jason-1 and Topex/Poseidon Precise Orbit ■11:30 - J. Ries - Orbit Error Budget for Jason-1 and Topex/Poseidon Precision Orbits ■11:45 - Ch. Foerste - On the use of Temporal Gravity Field Models Derived from GRACE for Altimeter Satellite Orbit Determination ■12:00 - P. Willis - Validation and Extension of ITRF2005 for DORIS POD ■12:15 - J. Ries - Validation and Extension of ITRF2005 for SLR POD

6. Ocean Topography Science Team Meeting - Hobart, Australia – March 2007 6 Afternoon session : Geoid and discussion ■16:30 - Discussion on key POD Issues: ITRF2005 implementation, time variable gravity, other model recommendations ■17:00 - J. Ries GRACE Mission Status and Current Results ■17:15 - R. Biancale EIGEN5 activities at GFZ and GRGS ■17:30 - X. Deng Assessment of Geoid Models off Western Australia Using Oceanographic In-Situ Measurements ■17:45 - M.-H. Rio Ocean Mean Dynamic Topography from Altimetry and GRACE: Toward a Realistic Estimation of the Error Field ■17:55 - Discussion on remaining Geoid Issues ■18:00 - Adjourn

7. Ocean Topography Science Team Meeting - Hobart, Australia – March 2007 7 POD/Geoid Posters ■A 4-year Series of Earth Mass Changes derived from GRACE and LAGEOS data R. Biancale, J.-M. Lemoine, S. Loyer;, S. Bruinsma, F. Perosanz, G. Balmino ■Validation Activities for Jason-1 and Topex/Poseidon Precise Orbits P. Bonnefond, P. Exertier, O. Laurain, P. Berio and D. Coulot ■Evaluation of Orbits for the WATER Hydrosphere Mapper Mission D. Chambers, R. D. Ray, J. C. Ries ■Toward EIGEN-05: Global Mean Gravity Field Models from Combination Of Satellite Mission and Altimetry/Gravimetry Surface Data C. Foerste, F. Flechtner, R. Schmidt, R. Koenig, Ul. Meyer, R. Stubenvoll, M. Rothacher, F.Barthelmes, H. Neumayer, R. Biancale, S. Bruinsma, J.-M. Lemoine, S. Loyer ■New Mean Sea Surface DNSC07 P. Knudsen, O. Andersen ■Evaluation of the Geosat and Geosat Follow-On Precise Orbit Ephemeris F. Lemoine, N.P. Zelensky, B.D. Beckley, D.S. Chinn, D.D. Rowlands, J.L. Lillibridge, R.Scharroo, W.H.F. Smith ■Jason 1 GPS Processing at CNES F. Mercier, L. Cerri, S. Houry, P. Perrachon, J.-P. Berthias ■Ocean Mean Dynamic Topography from altimetry and GRACE: toward a realistic estimation of the error field M.-H. Rio, P. Schaeffer,J.-M. Lemoine, G. Larnicol ■Validation and Extension of ITRF2005 for DORIS and SLR POD (DPOD2005 and LDPOD2005) P. Willis, J.C. Ries, F.G. Lemoine, E.C. Pavlis, L. Soudarin, N. Zelensky