Validation of Ionospheric Electron Density Measurements Derived from Spire CubeSat Constellation

Commercial Global Navigation Satellite System radio occultation ionospheric measurements collected by the Spire CubeSat constellation could significantly improve the determination of the global ionospheric state. However, the systematic validation work is needed before using the Spire data for scientific and assimilative purposes. In this work, the electron density profiles retrieved from Spire total electron content measurements using Abel inversion corrected by horizontal asymmetry are compared to digisonde measurements and Arecibo incoherent scatter radar data. Four events when the radio occultation measurements occurred close to three digisondes showed a strong agreement between these independent measurements. The comparison of F 2 layer peak and height obtained from Spire data to digisonde measurements at 34 stations around the globe from Global Ionospheric Radio Observatory network also showed a strong agreement. Additionally, a good agreement was obtained in the comparison of Spire profiles with Arecibo electron density measurements.