AGGA-4: Core device for GNSS space receivers of this decade

This paper presents the key elements of the next generation of miniaturised GNSS space receivers compatible with the new and improved GNSS signals from Galileo and modernized GPS. A quick review of applications like Precise Orbit Determination (POD) and Radio Occultation (RO) is provided together with the performance achieved in current satellites like MetOp and GOCE and that expected in future ESA satellites. The key architectural building blocks of future GNSS space receivers are presented, with special focus on the AGGA-4 (Advanced GPS / Galileo ASIC) baseband GNSS processor and, to a lesser extent, on programmable RF ASICs. These components, in combination with new features of the new GNSS signals, will bring a significant improvement with respect to their predecessors (e.g. AGGA-2) not only in terms of system robustness but also regarding miniaturization, which eventually could enable to have more GNSS space instruments in a larger number of EO satellites.