In-Orbit Demonstration of Precise Point Positioning for Real-Time On-Board High-Accuracy Orbit Estimation of LEO Satellites

In-Orbit Demonstration of Precise Point Positioning for Real-Time On-Board High-Accuracy Orbit Estimation of LEO Satellites

Utah State University, Logan, UT

Satellites in Low Earth Orbit (LEO) are typically equipped with GNSS (Global Navigation Satellite Systems) receivers to obtain real-time positioning, velocity, and timing. Until now, onboard GNSS positioning accuracy in LEO has been limited. Where more accurate state vector estimates are required the raw GNSS data must be post-processed on the ground.

Precise Point Positioning (PPP) is a GNSS positioning technique which allows users to obtain absolute high accuracy positioning. While PPP has been extensively used for precise Earth-based navigation, it has not been used for enhancing the positioning accuracy of satellites in LEO until now.

This paper describes how Fugro has utilised the PPP technique to estimate real-time nominal positioning at sub-decimetre levels of accuracy onboard satellites in LEO. This technology was demonstrated on Loft Orbital’s YAM-3 satellite. To the knowledge of the authors, this is the first time that such a level of positioning accuracy has been achieved on-board a LEO satellite in real-time. The system architecture used to deliver PPP-enabling corrections to LEO and the architecture onboard is described. The results from the demonstration are presented and some use cases that benefit from this enhanced onboard position, velocity, and time solution are highlighted.