The Earth's ionosphere is the ionized upper part of the Earth's atmosphere, located between about 60 km and 1000 km above the Earth. The plasmasphere is a torus of cold plasma in the inner magnetosphere, just outside the upper ionosphere, co-rotating with the Earth. The outer boundary of the plasmasphere is known as the plasmapause, which is defined by an order of magnitude drop in plasma density. During the propagation through the ionosphere and plasmasphere, L-band signals of GNSS satellites are delayed. The mitigation of ionospheric effects on radio waves is a critical issue for applications utilizing trans-ionospheric signals such as GNSS navigation, GNSS related augmentation systems (e.g. EGNOS and WAAS) and remote sensing. The reconstruction of the ionosphere and plasmasphere is one of the powerful tools to provide link specific ionospheric corrections as well as an important step towards a comprehensive understanding of the coupled system magnetosphere – plasmasphere – ionosphere – thermosphere. As a part of the DFG Priority Program “DynamicEarth”, the project MuSE aims at the development of a topside ionosphere-plasmasphere model, which is capable to assimilate various measurements and exploits especially the measurements of the low Earth orbiters of ESA’s Swarm mission. This presentation provides an overview of the MuSE project and the first achieved results. We discuss data assimilation procedures which are under development and testing and show first results of the reconstructed electron density. In addition, we outline the plasmapause location proxy, developed within MuSE on the basis of magnetic field data of the SWARM satellites. This proxy will be applied within the reconstruction procedure as a constraint for an appropriate initial guess of the ionosphere-plasmasphere state vector. Finally, open issues and next steps of the project are pointed out.     «

The Earth's ionosphere is the ionized upper part of the Earth's atmosphere, located between about 60 km and 1000 km above the Earth. The plasmasphere is a torus of cold plasma in the inner magnetosphere, just outside the upper ionosphere, co-rotating with the Earth. The outer boundary of the plasmasphere is known as the plasmapause, which is defined by an order of magnitude drop in plasma density. During the propagation through the ionosphere and plasmasphere, L-band signals of GNSS satellit...     »