1. COSMIC Program Office; University Corporation for Atmospheric Research; Boulder Colorado USA
2. High Altitude Observatory; National Center for Atmospheric Research; Boulder Colorado USA
3. Key Laboratory of Ionospheric Environment; Chinese Academy of Sciences, Institute of Geology and Geophysics; Beijing China
4. CAS Key Laboratory of Geospace Environment; Department of Geophysics and Planetary Sciences, University of Science and Technology of China; Hefei China
5. GPS Solutions, Inc.; Boulder Colorado USA