Changyong Cao is an advisor to the WMO/GSICS and former chair of the CEOS/WGCV (Committee on Earth Observation Satellites/Working Group on Calibration/Validation). He is the recipient of three gold and one silver medals from the Department of Commerce and NOAA for his achievements. Before joining NOAA, he was a senior remote sensing scientist with a leading aerospace company supporting NASA missions. He oversees the satellite instrument calibration and data assimilation branch which is responsible for the instrument performance and data quality for all operational polar-orbiting and geostationary satellites at NOAA. He leads the STAR radiance science team, Visible Infrared-Imaging Radiometer Suite (VIIRS) instrument calibration/validation team, and co-leads the GOES Advanced Baseline Imager (ABI) calibration working group (CWG). He developed the Simultaneous Nadir Overpass (SNO) inter-satellite calibration method, which has become one of the cornerstones of the WMO/Global Space-based Intercalibration System (GSICS), widely used for on-orbit instrument performance evaluation for Earth observation satellites, and for long-term time-series and climate change detection studies. He has broad research interests in satellite instrument performance characterization, exploration of novel uses of satellite observations, and new technologies.