The authors decided to compute a gravity anomaly, geoid and deflection of the vertical for GRACE, GOCO03S and EGM2008 models using [DELTA][C.sub.l,m] and [DELTA][S.sub.l,m].
* a comparison of GRACE, GOCO and EGM2008 models to the POLREF network for a better perception of the accuracy of the used models (gravity anomaly, geoid and deflection of the vertical were computed using spherical harmonic coefficients of GRACE, GOCO and EGM2008, and the statistical characteristics were provided),