GOCE gravity field model derived from orbit and gradiometry data applying the time-wise method

Abstract

A first GOCE gravity field model based on two months of GOCE orbit and gradiometry data has been computed applying the time-wise method. The paper gives an overview of the software system, and discusses the key features of the solution strategy. The resulting global gravity field model, resolved complete to degree/order 224, is GOCE-only in a strict sense, i.e., no a priori gravity field information entered the solution. Realistic stochastic models for both the orbit and gradiometer observations have been included. Thus, the coefficient error information, provided as full variance-covariance matrix, reflects the true error behaviour of the solution. The resulting GOCE model is assessed and validated against state-of-the art gravity field models. Since the model is independent of any gravity prior information, it can be used to assess the additional information content of GOCE, and can be combined with complementary satellite and terrestrial gravity field information.