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arXiv · 2611.02377

Clock-Shift-Aided Blind Doppler Matching in Passive SDR Monitoring Data for LEO Doppler Positioning

Seunghyeon Park·Gaeun Kim·Jiwon Seo
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Abstract

Low Earth orbit (LEO) satellite signals have recently attracted increasing attention as opportunistic signals for positioning, navigation, and timing. Most Doppler-based LEO positioning studies rely on tracked satellite signals or raw in-phase/quadrature (IQ) samples that preserve signal-level structures for acquisition, Doppler tracking, or satellite association. In contrast, passive software-defined radio (SDR) monitoring systems often retain only time-frequency power scans, in which LEO Doppler traces appear as unlabeled ridges without raw IQ samples or identifiable signal structures. This paper proposes a clock-shift-aided segment-based blind Doppler matching method that associates unlabeled Doppler traces with candidate satellites predicted using two-line element (TLE) data. The proposed framework consists of slope-consistent Doppler segment generation, clock-shift-aided temporal alignment, and multi-metric satellite matching based on Doppler-rate and trajectory-shape consistency. The proposed method was evaluated using a three-hour subset of open Starlink/OneWeb monitoring data collected in the United Kingdom. The clock-offset search selected an effective offset of +19 s, for which 56 of 69 segments had at least one slope-compatible candidate, compared with 19 segments at zero shift. Using the resulting satellite associations, the batch positioning error over the full three-hour period was 104.2 m, whereas the RMSE-based and slope-based simple-segment baselines failed to converge near the reference receiver location.

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Seunghyeon Park, Gaeun Kim, Jiwon Seo. 2026-11-02. Clock-Shift-Aided Blind Doppler Matching in Passive SDR Monitoring Data for LEO Doppler Positioning. https://arxiv.org/abs/2611.02377

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