HR: 0800h
AN: DI31A-0266    [Abstracts]
TI: Tetra-Frequency Spectrum Vector Method Of Resolving FCN Parameters From Tidal Data
AU: * Lei, X
EM: xiange_lei@yahoo.com.cn
AF: Institute of Geodesy and Geophysics, Chinese Academy of Sciences, 340 Xudong Street, Wuhan, 430077, China
AB: The parameters of Earth free core nutation (FCN) are two fairly important geophysical parameters, which provide some valuable constraints on the Earth's deep construction. The theoretical estimations of FCN parameters were provided by some researchers such as Sasao et al. (1980), Wahr and Bergen (1986) and Mathews et al. (2002). Gwinn, Herring and Shapiro (1987) first obtained the observational values of FCN parameters by very long base interference (VLBI). Neuberg, Zščrn and Hinderer (1987) began to retrieve FCN parameters from the observation of Earth tides and introduced the Stacking Method according to Marquardt algorithm. The later scholars basically followed the Stacking Method to check FCN parameters from tidal data. It is in fact a kind of non-linear inversion to resolve FCN parameters from tidal data, and there exists the phenomena of complex error transmission during the inversion process. Although Gauss distribution was satisfied by the observation errors of Earth tidal factors, the errors of resolved FCN parameters wouldn't follow the normal distribution. Not only the stacking method but also another resolution method (Florsch et al. 1994) could not provide the accurate description of resolution error of FCN parameters. We will introduce a new method called Tetra-Frequency Spectrum Vector Method (TFSVM) to resolve the FCN parameters from the gravity tidal data, which consists of two resolution steps: point resolution algorithm (PRA) and finite probability element method (FPEM). TFSVM can provide the accurate description of the error probability distribution of FCN parameters. After the precise analysis on the error probability distribution of FCN parameters resolved from Moxa station and Potsdam station, we found that the error distribution of FCN parameters is not satisfied with the normal distribution, and it might not be suitable for the classic error transmission law to study the resolution errors of FCN parameters. We believe that TFSVM would be able to promote the study of checking FCN parameters. Acknowledgements: This work is supported jointly by the National Natural Sciences Foundation of China (Grant No: 40404005) and the Excellent Prize of President Scholarship of CAS (Chinese Academy of Sciences). Thanks for the scientific invitation provided by Dr. Neumeyer and Prof. Rothacher in GFZ.
DE: 1507 Core processes (1213, 8115)
DE: 7207 Core (1212, 1213, 8124)
DE: 7208 Mantle (1212, 1213, 8124)
DE: 8115 Core processes (1213, 1507)
DE: 8120 Dynamics of lithosphere and mantle: general (1213)
SC: Study of the Earth's Deep Interior [DI]
MN: 2007 Fall Meeting