The GOCE Gravity Field Space Mission as an Important Step for the Exploration of our Planet

Abstract. As an integral response to its mass distribution, the structure of the Earth’s gravitational field represents an important source of information about our planet. Its knowledge is therefore important for the Earth as a system and for geodesy, solid Earth physics, and oceanography in particular. For the first time in space geodesy, dedicated gravity field missions are being realized during this decade. The three missions are based on different observation concepts but they have one element in common: GPS-based high-low satellite-to-satellite tracking (SST). A second dedicated on-board sensor makes the three missions focus on different aspects of the Earth’s gravity field: the determination of the static field with utmost precision and resolution by gravity gradiometry (GOCE mission) versus the monitoring of the temporal variable field with reduced spatial resolution by inter-satellite range measurements (GRACE mission). The two sensors of the GOCE mission (GOCE = Gravity field and steady-state Ocean Circulation Explorer) combined will deliver a global gravity field with unprecedented accuracy and resolution. The GOCE derived gravity field, if combined with satellite altimeter data, will allow the precise determination of the absolute ocean circulation on a global scale. Considerin