The gravity field and steady-state ocean circulation explorer (GOCE) (ESA 1999,Albertella et al. 2002, Balmino et al. 1998 and 2001) was finally launched on 17thMarch in 2009. In this satellite mission the second-order derivatives of the Earth’sgravitational potential are measured based on differential accelerometer at a satellitebornegradiometer. It is expected to recover the geopotential coefficients to higherdegrees and orders than those were obtained from the former satellite missions; sayup to degree and order 300. Such an Earth’s gravity model will have an accuracy of 1cm in global geoid height and of 1 mGal for the gravity anomalies, which areextremely good accuracies of the long-wavelength structure of the gravity field.

The present report is a summary of the studies of Mehdi Eshagh when a postdoct/research associate position in division of Geodesy was available for him. Theresearch work consists of the studies continuing his thesis work and completingproject no. 63/07:1, funded by the Swedish National Space Board (SNSB). Thereport is of collective papers type with a series of Papers A-Q. In the following wepresent summaries of his complementary studies. We just present the background ofeach study and the author’s contributions in comparing his research to others’ works.The details about the methodology, theory, numerical investigations and conclusionsare given in the corresponding papers of each subject