Numerical simulation of the gravity field recovery from GOCE mission data

摘要

Numerical simulations of the gravity field parameter recovery using the direct method, with satellite rectangular coordinates as pseudo observations, instead of simulating GPS Satellite-to-Satellite (SST) tracking data, and with gravity gradients (SGG data), were done and are ongoing in the framework of the European GOCE Gravity Consortium test and validation plan for GOCE mission data processing. The GOCE orbit perturbation analysis revealed a high sensitivity to sectorials and order 16, 32, 48 and 96 resonances of the gravity field, as well as very strong resonant effects due to the ocean tide, order 18 of the M2 constituent in particular. The simulations using pseudo SST observations demonstrated the known deteriorating effect of the polar gap on the determination of the zonal coefficients. The cumulated geoid error due to the SST part of the GOCE combined SST+SGG data gravity field solution is at the few mm level, at least for these simplified simulations.