The ionosphere is a highly variable medium in both, temporal and spatial changes, especially around 350 km and higher. Ground based observations, collected by GNSS stations and ionosondes, cannot capture the variations in the topside ionosphere at altitudes above ~350 km.

In contrast satellite missions with altitudes between 350 km and 1000 km exclusively provide topside observations. Almost all LEO satellites are equipped with a GNSS receivers, which allows for extraction of slant total electron content (TEC) observations, i.e. the integrated electron density along the line of sight. Based on slant TEC observations, the global electron density in the ionosphere can be reconstructed, given a sufficient satellite coverage.

The upcoming mega- and giga-constellations with hundreds or even thousands of LEO satellites will significantly improve the achievable resolution and precision of ionospheric models. In the framework of this project, we investigate methods for reconstructing the electron density as well as the potential for ionospheric monitoring in near real-time using large LEO constellations.

[1] Schreiter L, Brack A, Männel B, Schuh H, Arnold D, Jäggi A (2024): Imaging of the topside ionosphere using GNSS slant TEC obtained from LEO satellites. Submitted to Radio Science. Preprint at DOI: 10.22541/essoar.170612533.38060840/v1

[2] Stolle C, Siddiqui TA, Schreiter L, Das SK, Rusch I, Rother M (2023): An empirical model of the occurrence rate of low latitude post-sunset plasma irregularities derived from CHAMP and Swarm magnetic observations. Submitted to Space Weather. Preprint at DOI: 10.22541/essoar.170144054.42135952/v1

[3] Schreiter L, Stolle C, Rauberg J, Kervalishvili G, van den Ijssel J, Arnold D, Xiong C, Callegare A (2023): Topside ionosphere sounding from the CHAMP, GRACE, and GRACE-FO missions. Radio Science, 58:e2022RS007552. https://doi.org/10.1029/2022RS007552