Data Assimilation Techniques for Ionospheric Reference Scenarios – project overview and achieved results

Abstract

In order to conduct EGNOS performance simulations and to assure the capability for maintaining accuracy, integrity and availability of the EGNOS system, especially during ionospheric storm conditions, Ionospheric Reference Scenarios (IRSs) are applied by ESA to develop and validate its ionospheric corrections and error bounds. The currently used IRSs cover Europe and parts of Africa and are generated by the adjustment of the NeQuick model to vertical total electron content grids derived from ground-based GPS data. The project Data Assimilation Techniques for Ionospheric Reference Scenarios (DAIS) aims at the provision of improved EGNOS IRSs covering the extended EGNOS V3 service area (including remote areas or areas with less infrastructure). Time series of IRSs, covering ionospheric quiet and perturbed conditions, are generated by a 3D assimilation approach combining ionosonde, space- and ground-based GNSS measurements with an ionospheric background model. The special focus thereby is to demonstrate that space-based measurements can significantly improve the IRSs.