POD of LEO satellites

Precise Orbit Determination (POD) of Low Earth Orbiters (LEO) includes a complicated procedure of combining GNSS observations collected by the spaceborne receivers and comprehensive dynamic models and compensating model deficiencies with stochastic accelerations. This method called the reduced-dynamic POD provides the most precise orbits which are essential in many Earth science applications such as satellite altimetry, GNSS Radio occultation, InSAR missions, etc. There is also a purely Kinematic POD which is based on Precise Point Positioning (PPP) method and useful for gravity field recovery missions.

GNSS-SPAN group is currently working on a project entitled “Tracking Formation-Flying of Nanosatellites Using Inter-Satellite Links” funded by the Australian Research Council Discovery Scheme (ARC DP). The proposed research addresses this significant problem by developing novel kinematic methods that will utilise the new generation of multi-frequency and multi-constellation carrier-phase measurements of the Global Navigation Satellite Systems (GNSS) to provide reliable real-time precise orbit determination for the microsatellite. Accuracy at the cm level will be achieved compared to the current several meter accuracy, in both standalone mode, and in complex formation flying configurations. The realisation of such concept makes possible a significant increase in spacecraft autonomy, a vital feature in the new-generation intelligent satellite systems, and allows for real-time guidance and control of satellite formations; thereby creating a virtual platform for Earth- and space-science applications and expansion of space applications for CubeSats. Experimental validation of the developed methods will be performed using real data from state-of-the-art CubeSats.