Validation of GRACE and GRACE FO data across the gap between missions
Abstract
The last science data collected by the GRACE mission was in May 2017 and GRACE Follow-On data collection began over 12 months later. Unlike the satellite altimetry community, the space gravity community faces the task of validating the performance of the new mission against the previous mission with no overlapping observations. While it has been assumed that the results and products from the analysis of the GRACE mission data are accurate and do not need calibration, this won't be known definitively until agreement and consistency is demonstrated between GRACE and GRACE FO estimates. The key question for the scientific community is how to provide this validation of the two missions without overlapping observations. There are several possible ways of achieving this validation, including assessing estimates of geophysical signals (e.g. hydrological loading, low-frequency components of the gravity field, etc) from each space gravity mission and from independently observed sensor systems such as GPS.
In this presentation, we will assess how well both GRACE and GRACE FO estimates of loading deformation compare with independent estimates of crustal deformation measured by GPS. In essence, we rely on the continuous GPS estimates to bridge the gap in the space gravity data and provide the continuity of measurements. We will show how we extracted accurate temporal gravity field estimates from the last months of the GRACE mission data using the ANU GRACE software, our comparisons of GRACE and GPS loading estimates and first comparisons of GRACE FO and GPS.- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2018
- Bibcode:
- 2018AGUFM.G13C0553T
- Keywords:
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- 1217 Time variable gravity;
- GEODESY AND GRAVITYDE: 1218 Mass balance;
- GEODESY AND GRAVITYDE: 1223 Ocean/Earth/atmosphere/hydrosphere/cryosphere interactions;
- GEODESY AND GRAVITYDE: 1240 Satellite geodesy: results;
- GEODESY AND GRAVITY