GPS Based Precise Orbit Determination and Real-Time Navigation of the PROBA-2 Spacecraft

The PROBA-2 (Project for Onboard Autonomy) spacecraft is a micro-satellite serving as joint platform for technology demonstration and astronomical observations of the Sun. The satellite is equipped with two kinds of GPS receivers: a miniaturized single-frequency receiver (Phoenix-XNS) supporting the attitude and orbit control system and the first European space receiver for tracking the civil GPS signals on both the L1 and L2 frequency. Both receivers provide raw measurements for precise orbit determination on ground and are also equipped with a real-time navigation system enabling accurate onboard positioning. The paper discusses the flight performance of both receivers based on data collected during the first year of operation.