Intercalibration of the Plasma Density Measurements in Earth's Topside Ionosphere

Over the last 20 years, a large number of instruments have provided plasma density measurements in Earth's topside ionosphere. To utilize all collected observations for empirical modeling, it is necessary to ensure that they do not exhibit systematic differences and are adjusted same reference frame. In this study, we compare satellite from Gravity Recovery Climate Experiment (GRACE), Constellation Observing System Meteorology, Ionosphere, (COSMIC), CHAllenging Minisatellite Payload (CHAMP), Swarm, Communications/Navigation Outage Forecasting (C/NOFS) missions. Electron densities retrieved GRACE K-Band Ranging (KBR) system, previously shown be excellent agreement with incoherent scatter radar (ISR) measurements, used as reference. We find COSMIC radio occultation (RO) highly consistent GRACE-KBR showing mean relative difference <, therefore no calibration factors between them necessary. outstanding three-dimensional coverage ionosphere by mission perform conjunction analysis situ CHAMP, C/NOFS, Swarm CHAMP lower than ?. generally at daytime higher nighttime compared COSMIC. C/NOFS ion agree well COSMIC, bias The resulting cross-calibration factors, derived probability distribution functions, help eliminate leveling data sets, allow using these jointly ionospheric applications.