The ionosphere is the part of the upper atmosphere that is familiar to us as the region where we see the aurora. The ionosphere is very important because it affects radio signals in ways that that can either enhance or degrade our ability to communicate and navigate. For example the BBC world service is broadcast on high-frequency radio signals and is only possible to receive it in remote places because it is refracted back to the Earth by the ionosphere. In a way it is reflected with the upper atmosphere acting a bit like a mirror. On the other hand, your satnav system is affected by the ionosphere in a different way - sometimes the signals are delayed more than other times and may even be lost completely as they pass through the ionosphere. This fellowship is about making use of research level information about the ionosphere to improve the performance of radio systems in two areas: Global Navigation Satellite Systems (GNSS, satnav) and high-frequency communications. In addition to the aim of improving the reliability and accuracy of such systems it has a further aim of impacting policy. This will all be achieved by accurate simulations of the ionosphere, including the most extreme space weather events (like the famous Carrington Event of solar storms in 1859). These simulations will be translated in a form that can easily be used by the designers of the next-generation of GNSS and HF systems. This will ensure that radio systems are more accurate and reliable, both enhancing the benefit for UK companies and providing resilience for our infrastructure for the future.