Using a Block-Processing Discriminator for Precise Tracking of Starlink Signals

Christian A. Lichtenberger, Florian Binder, Ottavio M. Picchi, Francesco Menzione, and Thomas Pany

Abstract:	Signals of opportunity (SoOP) from low earth orbit (LEO) constellations such as Starlink are emerging as a promising complement or alternative to traditional global navigation satellite system (GNSS), offering stronger signals, larger bandwidths, and enhanced resilience to interference. This paper introduces a novel block-processing discriminator to be used within a GNSS tracking channel to provide stability even for discontinous broadcast of the signal. It keeps the signal reliably in lock by coherently accumulating multi-correlator outputs across consecutive frames. Implemented within the Multi-Sensor Navigation Analysis Tool (MuSNAT) software-defined radio (SDR) framework, the proposed method enables robust and precise code and frequency tracking of Starlink orthogonal frequency-division multiplexing (OFDM) signals, even when the replica is sparse using only primary synchronization sequence (PSS)/secondary synchronization sequence (SSS). Real-world experiments using Ku-band downlink recordings demonstrate that the approach achieves discriminator noise levels close to theoretical bounds and produces high-quality Doppler and code rate observables, even under suboptimal conditions. Compared with standard GNSS-like discriminators, the block-processing discriminator maintains lock more reliably and supports the derivation of precise navigation observables. These results highlight the potential of the technique to significantly enhance LEO-positioning, navigation and timing (PNT) performance and pave the way for hybrid positioning systems that integrate LEO constellations with GNSS.
Published in:	Proceedings of the 38th International Technical Meeting of the Satellite Division of The Institute of Navigation (ION GNSS+ 2025) September 8 - 12, 2025 Hilton Baltimore Inner Harbor Baltimore, Maryland
Pages:	3479 - 3491
Cite this article:	Lichtenberger, Christian A., Binder, Florian, Picchi, Ottavio M., Menzione, Francesco, Pany, Thomas, "Using a Block-Processing Discriminator for Precise Tracking of Starlink Signals," Proceedings of the 38th International Technical Meeting of the Satellite Division of The Institute of Navigation (ION GNSS+ 2025), Baltimore, Maryland, September 2025, pp. 3479-3491. https://doi.org/10.33012/2025.20465
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