Kian Bostani Nezhad, Technical University of Denmark; Kristian Aalling Soerensen, Technical University of Denmark; Henning Heiselberg, Technical University of Denmark; Hasse Bülow Pedersen, Technical University of Denmark
https://doi.org/10.64861/KOLJ4253
Keywords: GNSS, Jamming, GNSS interference, LEO, Precise Orbit Determination, LEO, In-orbit GNSS, GNSS RFI
Abstract:
Global Navigation Satellite Systems (GNSS) provide critical Positioning, Navigation, and Timing (PNT) services for Low Earth Orbit (LEO) satellites and support a wide range of spacecraft operations, including instrument pointing, Earth observation geolocation, and time synchronization. In recent years, large-scale GNSS interference in the form of jamming and spoofing has become increasingly prevalent across Europe, with significant impacts reported by aviation, maritime, and terrestrial users. While the presence of GNSS interference on Earth is well documented, its presence in space and impact on spaceborne GNSS receivers remains insufficiently characterized.
This study presents a multi-mission analysis of a GNSS interference phenomenon observed from LEO over Europe using openly available GNSS observations from the ESA Swarm constellation, Copernicus Sentinel satellites, and GNSS Radio Occultation missions. These platforms provide complementary data from different receivers, orbits, and GNSS observables, enabling a broad and generalized assessment of the interference under study.
This study documents both the current and historical state of the GNSS interference in LEO over Europe through extensive analysis of multi-year datasets. The study focuses on characterizing the scope and behavior of the interference by examining its temporal evolution, geographical occurrence, the GNSS constellations and frequency bands affected, and the estimated power of the underlying interference sources. Attention is given to identifying recurring spatial and temporal patterns and determining whether interference events are persistent in nature. The study further includes a preliminary assessment of likely sources based on recurring patterns observed in the measurements and the estimated severity of the observed signal degradation.
The results reveal recurring and geographically concentrated degradation signatures across Europe, particularly over and surrounding Eastern Europe. Several of the considered missions exhibit consistent reductions in carrier-to-noise levels when over these regions, with some experiencing degradation severe enough to result in the loss of GNSS observations. Similar interference patterns are observed across multiple receiver types, orbits, and GNSS constellations and frequency bands, indicating that the interference is broad and not targeted towards specific receivers, frequencies, or GNSS constellations. The spread and pattern of the interference suggest one or more terrestrial interference sources located somewhere in western Russia and/or eastern Ukraine. Analysis of multi-year datasets further indicates that the occurrence and geographical extent of the interference have increased over time, with noticeable dips in carrier-to-noise estimates beginning to occur in 2024. The persistence and continuity of the observed interference suggest a stable and recurring source of interference. Collectively, these observations demonstrate that terrestrial interference sources can produce measurable and operationally relevant impacts on GNSS reception in LEO.
These findings provide a space-based perspective to the ongoing efforts to monitor GNSS interference. The increasing occurrence, geographical extent, and severity of the observed interference highlight the importance of continued monitoring of GNSS as a part of maintaining space situational awareness. By identifying and characterizing these interference effects, the results can support spacecraft developers, operators, and mission planners in anticipating GNSS-related risks and implementing appropriate mitigation and resilience measures for current and future missions that rely on GNSS services.
Date of Conference: September 15-18, 2026
Track: Space-Based Assets