1. Jet Propulsion Laboratory California Institute of Technology Pasadena CA USA
2. Helmholtz Centre Potsdam GFZ German Research Centre for Geosciences Potsdam Germany
3. FG Physical Geodesy Technische Universität Berlin Berlin Germany
4. Center for Space Research The University of Texas at Austin Austin TX USA
5. Geodesy and Geophysics Laboratory NASA Goddard Space Flight Center Greenbelt MD USA