HR: 0800h
AN: G31C-0820    [Abstracts]
TI: Combining GRACE Data With Sea Surface and Terrestrial Gravity Data for Global Geopotential Modeling
AU: * Ries, J
EM: ries@csr.utexas.edu
AF: Center for Space Research, 3925 W. Braker Lane Suite 200, Austin, TX 78753 United States
AU: Bettadpur, S
EM: srinivas@csr.utexas.edu
AF: Center for Space Research, 3925 W. Braker Lane Suite 200, Austin, TX 78753 United States
AU: Chambers, D
EM: chambers@csr.utexas.edu
AF: Center for Space Research, 3925 W. Braker Lane Suite 200, Austin, TX 78753 United States
AU: Cheng, M
EM: cheng@csr.utexas.edu
AF: Center for Space Research, 3925 W. Braker Lane Suite 200, Austin, TX 78753 United States
AU: Condi, F
EM: fcondi@csr.utexas.edu
AF: Center for Space Research, 3925 W. Braker Lane Suite 200, Austin, TX 78753 United States
AU: Gunter, B
EM: gunter@csr.utexas.edu
AF: Center for Space Research, 3925 W. Braker Lane Suite 200, Austin, TX 78753 United States
AU: Poole, S
EM: poole@csr.utexas.edu
AF: Center for Space Research, 3925 W. Braker Lane Suite 200, Austin, TX 78753 United States
AU: Tapley, B
EM: tapley@csr.utexas.edu
AF: Center for Space Research, 3925 W. Braker Lane Suite 200, Austin, TX 78753 United States
AB: The optimal combination of the very accurate gravity information from GRACE with terrestrial and marine gravity information is a challenging task. One aspect of the challenge is to preserve the very high accuracy of the low-degree field estimates from GRACE while blending this information with terrestrial gravity data. A second aspect is to use a technique that requires no assumptions about density for reducing data to a single surface, or puts any restrictions on data type, geographic distribution, or weighting. Using a new out-of-core algorithm, a rigorous estimate of a full 360x360 field (with full covariance) has been obtained using a single IBM P690 node with only 32 GB of memory. Unlike traditional techniques, this method does not use block diagonal or quadrature-like methods and is not limited in the maximum degree of the full covariance. The combination field is shown to successfully blend the accurate, low-degree information from GRACE with high degree information from other gravity data. Its evaluation with respect to its application to oceanography, leveling and orbit determination shows it to be superior to previously available mean Earth gravity fields.
UR: http://www.csr.utexas.edu/grace
DE: 1214 Geopotential theory and determination
DE: 1241 Satellite orbits
SC: Geodesy [G]
MN: 2004 AGU Fall Meeting