Residual GNSS Ionospheric Error Analysis in Future Low Earth Orbit Applications

Kurzfassung

Future low Earth orbit (LEO) applications such as LEO positioning, navigation, and timing (PNT) and LEO-based monitoring of global navigation satellite systems (GNSS) are expected to experience a residual ionospheric delay depending on the altitude a constellation would be deployed. The ionosphere reaches its peak concentration in the F-region at and altitude of 300 km to 400 km. The concentrations of charged particles beyond this altitude constitute the topside ionosphere and may contain a non-negligible density as high up as 1000 km. The literature on dealing with the residual ionospheric error is scarce, and the impact of the residual error has not been yet studied thoroughly in the context of future LEO applications. In this paper we aim to quantify and analyze this residual error. We aid our analysis with 3D-ionospheric model estimates and compare them to collected in-situ total electron content (TEC) measurements from LEO. Thus, we aim to characterize the expected uncorrected error magnitude and its distribution for a single-frequency GNSS receiver depending on the LEO altitude, and on the solar and geomagnetic activity