GOCE mission

Preprocessing of satellite gravity gradient of GOCE mission

GOCE satellite was launched in 2009 on a low (260 km) orbit and it contains the electrostatic gravity gradiometer which is destining for measuring of gravity gradients. In the paper the algorithm of using of quaternions during the transformation of gravity gradients from the system GRF (Gradiometer Reference Frame) to LNOF (Local North Oriented Frame) is shown. Mathematical verification of intermediate calculations is realized and methods of improvement of data using are shown.

Reduction of the gravity vertical gradients to a spherical surface

The GOCE mission has produced gravity gradient data during 2009–2013 years. Various data sets were obtained, such as: tensor of second derivatives in different systems, satellite orbit parameters, the models of the gravitational field of the Earth. In contrast to the direct approach, space-wise-approach, and time-wise approach the construction of the spherical grid of gradients were orthogonality relationships are carry out, was developed via upward/downward continuation to sphere. This paper considers the vertical gravity gradients zz V (EGG TRF2 [Gruber Th., 2010]) in particular.