1. Space Research Institute, Austrian Academy of Sciences Graz Austria
2. Institute of Physics University of Graz Graz Austria
3. Institute of Geodesy Graz University of Technology Graz Austria
4. RAL Space, Rutherford Appleton Laboratory Didcot UK
5. Conrad Observatory, Zentralanstalt für Meteorologie und Geodynamik Vienna Austria
6. Hvar Observatory, Faculty of Geodesy University of Zagreb Zagreb Croatia