Towards a Roadmap for Future Satellite Gravity Missions September 30 - October 2, 2009, Graz, Austria

Recommendations of the 2007 Workshop on The Future of Satellite Gravimetry

The following Recommendations are taken from Koop, R. and Rummel, R., 2008. The Future of Satellite Gravimetry - Report from the Workshop on The Future of Satellite Gravimetry, 12-13 April 2007, ESTEC, Noordwijk, The Netherlands. German Geodetic Institute, Munich, Germany, available as pdf.

"On 12-13 April 2007 an International Workshop on The Future of Satellite Gravimetry took place at ESA/ESTEC, Noordwijk, The Netherlands. About 50 leaders from Earth sciences, fundamental physics and technology related to the field of satellite gravimetry participated. In a unanimous vote the workshop participants came to the following recommendations:

1. GRACE is demonstrating very successfully to provide monthly time series of changes in the Earth’s gravity field. This adds a new – and very central – parameter set to the study of Global Change phenomena such as deglaciation in the large ice shields of Antarctica and Greenland or the variations of the global water cycle.
2. GOCE – to be launched 2008 – is expected to deliver the global static gravity field and geoid with unprecedented precision and spatial resolution. It will in particular serve as reference for global ocean circulation studies by altimetry.
3. • a. In view of science achievements and the current performance of GRACE the participants of the workshop strongly support the idea of a GRACE follow-on mission based on the present configuration, with emphasis on the uninterrupted continuation of time series of global gravity changes. This should be short-term (Launch ~2011 TBD) priority one.
   • b. In parallel, investigations into the reduction of the aliasing problem offers even greater science benefits by increased spatial resolution and accuracy and should therefore have high priority.
4. Medium term priority should be focused on higher precision and higher resolution in space and time. This step requires (1) the reduction of the current level of aliasing (of high frequency phenomena, in particular tides, into the time series), (2) the elimination of systematic distortions (caused by the peculiar non-isotropic sensitivity of a single pair low-low SST), and (3) the improvement of the separability of the observed geophysical signals. Elements of a strategy in this direction are configuration flights, multi-satellite systems, improved data processing methodologies and improved and comprehensive Earth System modeling.
   This will open the door to a more efficient use of improved sensor systems, such as optical ranging systems, quantum gravity sensors, and active angular and drag-free control.
5. The long term strategy should include the gravimetric use of advanced clocks (ground based and flying clocks), micro-satellite systems, and space-qualified quantum gravity sensors.
6. The participants of the workshop support the activities and developments towards a future satellite gravity mission.
7. The workshop results will be offered to national and international space agencies and other relevant institutions.
8. The initiative will be taken to set up an international steering/working group or platform to coordinate the future activities and actions in this field.
9. Links between the geodetic and Earth science community with the communities from fundamental physics will be strengthened and/or established.