A New Method for Real-Time PPP Correction Updates

Real-time Precise Point Positioning (PPP) is expected to find more and more applications with various precise satellite orbit and clock products becoming more easily and reliably available. A crucial aspect for current real-time PPP system is the transmission of precise satellite orbit and clock correction data to the PPP users at a high update rate, typically 1-2 min for orbit corrections and 1-10 s for clock corrections. Such a high update rate is a challenge to many applications since it requires continuous data links for PPP users to timely receive the correction data. Therefore, latency and loss of the correction data incurred by the data links aremajor concerns in addition to communication cost. This paper describes a new correction update method with potential to address the concerns, which transmits initial parameters for orbit and clock to the users which can be at a much lower update rate. The preliminary numerical results have been provided with encouraging performance.