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Review of the use of satellite crossover altimetry

Jaroslav Klokocnik(1)

(1) Astronom. Inst. Czech Acad. Sci., CZ 251 65 Ondrejov Obs., 251 65 Ondrejov, Czech rep, Czech Republic


C. Wagner1, J. Klokocnik 2,3, J. Kostelecky 3,4,5, Ch.Gruber 2

1 National Oceanic and Atmospheric Administration, Lab. for Satellite Altimetry, 1335 East-West Highway, Silver Spring, MD, USA

2 Astronomical Institute, Academy of Sciences of the Czech Republic, CZ-251 65 Ondrejov Observatory, Czech Republic,,

3 CEDR (Center for Earth Dynamics Research), Prague-Ondrejov

4 Research Institute for Geodesy, Topography and Cartography, CZ-250 66 Zdiby 98, Czech Republic,

5 Department of Higher Geodesy, Czech Technical University, CZ- 166 29 Praha 6, Thakurova 7, Czech Republic,

The majority of older as well as recent gravity field models did not use satellite crossover altimetry (SCA) which does not contain the strong signals of surface gravity. Therefore SCA can be used in principal to test the accuracy of the low degree and order portions of these models provided the SCA data is precise and accurate enough. If these conditions are met a calibration of these models is possible with SCA if their formal covariance matrices are also available. The method was developed and used to test many such models since 1992. We outline the results of such testing, including the identification of model deficiencies, with a focus on those with CHAMP data. We find that current SCA is accurate enough to test all models up to those with CHAMP data. To calibrate GRACE models will require an improvement in the accuracy of the long-term averaged SCA (with better models of media effects) including a recalculation of the altimetric satellite orbits using GRACE geopotentials.


Workshop poster


                 Last modified: 07.10.03