1. Lowell Digisonde International; Lowell MA USA
2. Space Science Laboratory; University of Massachusetts Lowell; Lowell MA USA
3. National Observatory of Athens; IAASARS; Penteli Greece
4. Institute for Scientific Research; Boston College; Chestnut Hill MA USA
5. Observatori de l'Ebre, CSIC; Universitat Ramon Llull; Roquetes Spain
6. Institute of Atmospheric Physics; Czech Academy of Sciences; Prague Czech Republic
7. Leibniz-Institute of Atmospheric Physics; Kühlungsborn Germany
8. Royal Meteorological Institute; Brussels Belgium
9. INAF; Trieste Italy
10. Space Weather Services; Australian Bureau of Meteorology; Melbourne Victoria Australia
11. National Institute of Information and Communications Technology; Tokyo Japan