1. PMOD/WRC, Davos Dorf, Switzerland
2. Institute for Meteorology and Climatology, Leibniz University Hannover, Hannover, Germany
3. Geodesy Group, Department for Sustainability and Planning, Aalborg University, Aalborg, Denmark
4. Physical-Meteorological Observatorium Davos/World Radiation Center, Davos Dorf, Switzerland
5. School of Civil and Surveying and Mapping Engineering, Jiangxi University of Science and Technology, Ganzhou, China
6. World Standard Group (WSG) with PMOD/WRC, Davos Dorf, Switzerland
7. Institute Dom Luiz, University of Beira Interior, Covilha, Portugal
8. Division of Geodetic Science, School of Earth Sciences, The Ohio State University Columbus, OH, USA