1. Jet Propulsion Laboratory; California Institute of Technology; Pasadena California USA
2. Department of Geophysics, Faculty of Mathematics and Physics; Charles University; Prague Czech Republic
3. Department of Geophysics, School of Earth, Energy, and Environmental Sciences; Stanford University; Stanford California USA
4. Institute for Geophysics, John A. and Katherine G. Jackson School of Geosciences; University of Texas at Austin; Austin Texas USA