Development and Assessment of GRACE Derived Gravity Field Monthly Solutions
Abstract
Recent gravity field satellite missions like CHAMP and particularly GRACE have given us the opportunity to solve for Stokes' coefficients of the Earth gravity field on a monthly basis up to higher resolutions than before, when they were limited to very low harmonic degrees using SLR data. Nevertheless, pertinent results may depend on many particularities of data processing, on combining GPS, Kb-range, Kb-range-rate and even SLR measurements, on their relative weighting, on a priori models chosen, on the strategy applied for "instrumental" parameters relative to the GRACE K-band system or to (Super-)STAR accelerometer. The estimation of J2 is not accurate with CHAMP and GRACE data, and LAGEOS data may still be necessary to remedy this problem. Moreover, it becomes difficult to assess the accuracy of the generated models based on the different tests available to us: formal errors, internal consistency, and comparison to external data or models. We propose to synthesize some recent developments made in CNES/GFZ concerning both the strategy of processing and the assessment of models, the barotropic ocean model in particular. To that purpose, monthly gravity field solutions are computed using GRACE data, incorporating CHAMP data and LAGEOS data as well.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2004
- Bibcode:
- 2004AGUFM.G23A..02B
- Keywords:
-
- 1214 Geopotential theory and determination