Opportunistic Positioning with Starlink and OneWeb LEO Ku-band Signals

The simultaneous exploitation of Starlink and OneWeb Ku-band broadband low Earth orbit (LEO) constellations for opportunistic positioning is studied. First, an overview of the Starlink and OneWeb LEO constellations is presented, discussing their orbital parameters as well as their signal structure. Second, experimental results are presented demonstrating successful tracking of 6 Starlink and 7 OneWeb satellites using their Ku-band downlink signals during the course of 15 minutes. A batch weighted nonlinear least squares Doppler positioning framework is employed to localize a stationary receiver. Monte Carlo experimental results are presented showing that starting from an initial estimate 150 km away, a final two-dimensional (2D) positioning error of 6, 4, and 2 m was achieved with Starlink, OneWeb, and both constellations, respectively. Finally, as expected from their orbital design, the final estimation uncertainty ellipse showed uniformity in the up and east directions for the Starlink constellation, which employs a walker delta design; whereas the ellipse corresponding to the OneWeb constellation showed high uncertainty in the east direction due to the walker star design of the constellation.