|The main goal of the GOCE mission is to determine the Earthâ€™s stationary gravity field with unprecedented accuracy and resolution.
Applications are expected in the area of marine geoid determination, a better understanding of the Earthâ€™s interior, global height datum unification and the estimation of mass and thickness of polar ice sheets.
In addition to these main objectives, this study focuses on what GOCE may also contribute to the observation and understanding of the Earthâ€™s time-variable gravity field. On the one hand, GOCE is in a very low orbit with a constant mean altitude and a regular ground-track pattern. In addition, the available power on board of GOCE allows a continuous observation, also during the so-called eclipse phases.
Gravity fields derived from GOCE GPS tracking and gravity gradient data may therefore give complementary information on temporal gravity field variations to what GRACE observes. Because of the K-Band ranging between the two GRACE satellites, GRACE is in principle better suited to detect the time-varying gravity field, but in contrast to GOCE, GRACE is at higher altitude and has an irregular ground-track pattern.
On the other hand, the GOCE gravity gradients provide extremely accurate 3D information on the short wavelengths of the gravity field. It is therefore of interest to also study time-varying episodic events (earthquakes) with a large amplitude. Until now it has not been studied whether such events would be visible in the GOCE gravity gradients.