This volume in the Space Sciences Series of ISSI is dedicated to the detennination of the Earth's gravity field, which was the topic of a workshop organized by ISSI from 11 to 15 March 2002 in Bern. The aim of the meeting was to gather active researchers from various fields (satellite geodesy, gravity field modelling, solid Earth physics, oceanography, etc.) to assess the exciting new developments that are made possible by space missions currently...