Network-Aided Pseudorange-Based LEO PNT from OneWeb

This paper presents a framework and first experimental results for pseudorange-based positioning, navigation, and timing (PNT) exploiting OneWeb’s Ku-band downlink signal and a reference network. As the demand for accurate and resilient positioning and timing solutions grows, the proliferation of low Earth orbit (LEO) satellites, including approximately 650 in OneWeb’s constellation, offers promising opportunities for powerful new PNT services. Newly discovered synchronization sequences embedded in the OneWeb signal open the way for third-party provision of highly accurate clock and orbital models for each OneWeb satellite. Model parameters would be continually estimated by a sparse network of reference stations at known locations having access to an accurate universal time scale such as UTC. Subscribers to the third party’s data feed could treat OneWeb much like a traditional GNSS, extracting pseudorange, carrier phase, and Doppler observables directly from the OneWeb signals, either by exploiting only the newly discovered synchronization sequences or augmenting these with additional sequences decoded continuously by the reference network. The observables would then be processed together with the third-party-provided models to produce highly accurate position, velocity, and timing solutions. Because each OneWeb satellite illuminates a wide geographic area, this technique could be implemented with an attractively low density of reference stations. In this paper we develop the OneWeb satellite clock model, establish its applicability across multiple downlink beams, analyze the effect of ephemeris errors on the resulting solution, and prove the technique in a field experiment with live signals, achieving sub-meter-level positioning and timing.