Combination of ground gravimetry and GOCE data for local geoid determination: A simulation study

Abstract

The satellite gravity field mission GOCE will deliver data and products such as orbit tracking data, observations of the second order derivatives of the gravitational potential and global gravity field models. The space-wise approach will produce filtered versions of these observations, as well as a gravity field model. Local geoid determination is traditionally made using gravity anomaly data and a global gravity field model as reference, according to the remove-restore technique. Therefore the contribution of the GOCE mission to such a computation can be the global model that is expected to be of high quality. Apart from that, the filtered observations from the spacewise approach can be used as an additional data set. These expected contributions are evaluated here via simulations. Geoid heights and gravity anomalies are simulated in the Piemonte area in north-western Italy and solutions by least squares collocation are obtained. It is found that using a GOCE reference model with very accurate low degree coefficients leads to better results with respect to older models of lower long wavelength accuracy. When filtered second radial derivatives of the potential coming from the space-wise approach are additionally included it is seen that results improve even more