Recovering Earth's Gravitational Field Model Using GOCE Satellite Orbits

Mathematical models of integral equation approach to recover the Earth's gravitational field have been presented.Several gravitational field models have been recovered based on GOCE orbits of 61 days from 2009-11-02 to 2010-01-02.The results show that the long wavelength information of gravitational field can be effectively extracted from GOCE orbits,which complements the band-limitation of GOCE gradiometers.The geoid height error is ±9.6 cm with degree and order 106.The precision is higher than that from EIGEN-CHAMP03S and GRACE model from 2 months orbits.But the precision of zonal coefficients is low due to the polar gap.The geoid error of the model which combines the orbits of GOCE and GRACE satellites is ±6.9 cm with degree and order 106,which complements the orbital deficiency of GOCE satellite.