GOCE Level-2 Gravity Field Processing Chain

The GOCE Level-2 Gravity Field Processing Chain is operated by the European GOCE Gravity Consortium (EGG-C), contracted by ESA.^[1] EGG-C comprises 8^[2] to 9^[3] European scientific institutions. Member organisations include Technische Universitaet Muenchen (IAPG/TUM), the University of Bern (AIUB), CNES, Delft University of Technology, the University of Bonn (ITG), Politecnico di Milano, Graz University of Technology (TUG), and GFZ Potsdam.

The chain runs three independent processing approaches in parallel: Time-Wise (TIM), Direct (DIR), and Space-Wise (SPW).^[1] Inputs are Level-1b data from the GOCE EGG electrostatic gravity gradiometer and the SSTI 12-channel dual-frequency GPS receiver operating at 1 Hz. Each approach produces a sequence of static gravity field model releases: TIM and DIR each ran through Release 6 (R1-R6); SPW reached Release 5 (R1-R5). Six DIR releases were published through 2019. The final 2019 ESA Release 6 incorporated reprocessed gradients from the full GOCE mission period (2009-2013).^[4]

The combined model EIGEN-6C4, which integrates GOCE outputs with data from other gravity missions, reaches spherical harmonic degree and order 2190, corresponding to approximately 10 km spatial resolution. Gravity field models and gridded products are distributed through ICGEM (International Centre for Global Earth Models).^[2]