Electron density reconstruction using fleets of LEO satellites

An ever-increasing fleet of low earth orbiting (LEO) satellites equipped with dual-frequency GNSS receivers can provide slant TEC observations of the topside ionosphere. If occultation measurements are included, the observed range is extended well below LEO altitude also covering the peak of the F2 layer. To reconstruct the topside electron density a large number of observations with good coverage across magnetic latitude and local time with a large variety of elevation angles are required.

 

Apart from scientific missions like Swarm, GRACE-FO, Sentinel-1/2/3, Jason-3, and COSMIC-2 large fleets of LEO satellites operated by new-space companies like Spire Global help to increase the observation density. The Spire Lemur satellites are 3U cubesats, which carry dual-frequency GPS receivers and thus allow to compute slant TEC measurements.

 

We will discuss the data quality of TEC measurements derived by both, the scientific and new-space cubesat satellite missions and include Spire GPS data into a three-dimensional ionospheric reconstruction together with GPS data from Swarm, GRACE-FO, Sentinel, Jason-3, and COSMIC-2. B-Splines are used to represent the electron density in magnetic latitude, magnetic local time and altitude. Code biases are co-estimated. Since the scientific satellite missions, apart from the low inclination COSMIC-2 satellites, are in polar obits, special emphasis will be put on the improvements in observation geometry provided by the Spire Lemur satellites.