Funded by the European Space Agency

ESA’s Gravity field and steady-state Ocean Circulation Explorer (GOCE) mission was the first Earth Explorer mission in orbit and was dedicated to map the Earth gravity field with unrivalled precision. It was launched on 17 March 2009 and came to a natural end on 21 October 2013 after it ran out of fuel. The GOCE mission delivered a wealth of data, and providing the most accurate model of the ‘geoid’ ever produced to further our understanding of how the “system Earth” works.

GOCE was an ESA geodynamics and geodetic mission, a combined SGG (Satellite Gravity Gradiometry) and SST (Satellite-to-Satellite Tracking) mission. It was in a sun-synchronous orbit at an average altitude of 250 – 270 km with an inclination of 96.7°. The overall mission objective was to obtain measurements with a high spatial resolution (a completely new range of spatial scales, in the order of 100 km) and high accuracy (homogeneous accuracy). It had half-wavelength spatial resolutions in terms of geoid height and gravity anomaly accuracies varying from 20 – 20000 km depending on its application.

POLIMI was one of the official ESA centers for GOCE mission data analysis and gravity field computation, in the framework of the ESA High-level Processing Facility (HPF). For this purpose, the SATGEO team developed and applied its own data analysis ‘SPACE-WISE’ approach for the reconstruction of the global Earth gravity field. This approach is based on a gridding by least squares collocation (LSC) locally adapting the signal spatial correlation and considering the noise time correlation of the on-board gradiometer.