Multi-approach gravity field models from Swarm GPS data
Abstract
Although the knowledge of the gravity of the Earth has improved considerably with the CHAMP, GRACE and GOCE satellite missions, the geophysical community has identified the need for continued monitoring of its time-variable component with the purpose of estimating the hydrological and glaciological yearly cycles and long-term trends. The GRACE mission stopped its observation of the time variable gravity field at the end of 2017. The currently foreseen launch of GRACE Follow-On will be early 2018, such that a gap arises. This project aims at providing high-quality gravity field models from Swarm data that constitute an alternative source of gravimetric data, which could help alleviate this gap, as well as the short gaps that are present in the final stages of the GRACE mission. Independent from the existence of gravimetric data from dedicated satellite missions, the gravity field models derived from Swarm GPS data constitute an independent source of information about Earth's gravity field for e.g. monitoring of large mass transport processes.Recently, the geodetic community has realized that the combination of the different gravity field solutions is superior to any individual model. We intend to exploit this fact and deliver the highest quality gravity field models, resulting from the combination of four different gravity field estimation approaches. In addition, we intend to evaluate the possibly added value of kinematic baseline solutions for the lower pair of Swarm satellites, which fly in a pendulum formation. To this aim, two different kinematic baseline solutions will be studied. In addition, two different models of non-gravitational forces will be used as well as observed non-gravitational accelerations for Swarm-C to assess the importance of separating conservative from non-conservative forces.
- Publication:
-
42nd COSPAR Scientific Assembly
- Pub Date:
- July 2018
- Bibcode:
- 2018cosp...42E3549V