FORMOSAT-3/COSMIC-1

FORMOSAT-3/COSMIC-1 was a Taiwan–United States constellation of six satellites using GPS radio occultation for atmospheric and ionospheric sounding. Launched from Vandenberg on April 15, 2006, it measured how navigation signals change while passing through Earth’s atmosphere, supporting vertical profiles used in weather forecasting, climate research and space-weather studies. Its global sampling added information over oceans and near the poles where conventional observations are sparse. UCAR identifies the mission as retired in 2020. The historical data record remains available for reprocessing and long-term analysis.