Validation of COSMIC-2 Space Weather Science Products

The Constellation Observing System for Meteorology, Ionosphere and Climate (COSMIC-2) mission is a collaboration between the United States of America (NOAA and the USAF) and Taiwan (where it is called FORMOSAT-7). Following the successful launch of the COSMIC-2 satellites on June 24, 2019, the COSMIC-2 program has completed Early Orbit checkout and commissioning activities and is now engaged in sensor Calibration/Validation activities. Each COSMIC-2 satellite includes three space weather sensors: the primary Tri-GNSS Radio occultation Sensor (TGRS), developed by the Jet Propulsion Laboratory (JPL), which also has terrestrial weather sensing capabilities, the Ion Velocity Meter (IVM), designed by the University of Texas at Dallas (UTD), and the Radio Frequency (RF) Beacon, designed by SRI. These three instruments are providing a wealth of data needed to address topics associated with specification and forecast of ionospheric densities, as well as the instabilities and irregularities that cause ionospheric scintillation. The TGRSsensor measures ionospheric Total Electron Content (TEC) in both the radio occultation (RO) limb-viewing and overhead geometries, exploiting signals for both the GPS and GLONASS navigation satellites to make these observations. The COSMIC-2 program is striving to meet 3 and 0.3 TECu absolute and relative accuracy requirements, respectively. TGRSalso performs routine on-board calculations of ionospheric scintillation parameters and sends the underlying high rate observations to the ground for selected events. The IVM sensors measure both in-situ ion densities and plasma drifts from which electric fields, the most important physical driver for equatorial ionospheric structure, can be inferred. The U-, L- and S-band signals transmitted by the RF Beacon are measured by special purpose ground receivers, directly measuring scintillation effects on trans-ionospheric signal propagation across a broad frequency spectrum. This presentation will provide an overview of the ongoing validation activities associated with these important sensor products.