Global Navigation Satellite Systems (GNSS) transmit extremely weak signals that are vulnerable to interference and intentional jamming. Flex power technology allows ground controllers to redistribute signal energy, strengthening specific transmissions without increasing total satellite power. While this improves anti-interference capability, it also alters signal characteristics and introduces unexpected errors into high-precision positioning processes. Variations in signal strength can affect parameters such as code bias, satellite clock offset, and ionospheric corrections, potentially degrading positioning accuracy. Existing detection approaches remain limited, especially for the rapidly evolving BDS, and conventional processing models struggle to adapt to dynamic signal behavior. Based on these challenges, in-depth research is needed to understand and mitigate the impacts of flex power on satellite navigation performance.
Researchers from Space Engineering University, the Beijing Institute of Tracking and Telecommunications Technology, the Shanghai Astronomical Observatory of the Chinese Academy of Sciences, Henan Polytechnic University, Shandong University of Science and Technology, and Wuhan University reported the findings (DOI: 10.1186/s43020-026-00190-3) in Satellite Navigation (2026) a comprehensive investigation into flex power operations in the GPS and the BDS. The study analyzed operational modes, developed a new detection method combining signal-to-noise measurements with hardware delay indicators, and evaluated impacts across positioning algorithms. Published in 2026, the work presents an integrated framework designed to maintain resilient PNT services under dynamically changing satellite signal conditions.
The team first examined how flex power redistributes signal energy across satellite channels. Unlike normal operations, flex power produces step-like variations in carrier-to-noise ratios, creating detectable signatures in observation data. Building on this insight, researchers proposed a dual-indicator detection approach combining carrier-to-noise density (C/N₀) measurements with hardware delay variations. This method significantly reduces false alarms while enabling accurate detection across both GPS and BDS.
The study then evaluated how flex power influences multiple components of high-precision navigation. Results showed that GPS signals remain relatively stable, whereas BDS satellites exhibit stronger sensitivity, with noticeable changes in code bias and observation consistency. To address these disruptions, the researchers introduced “resilient” estimation strategies that dynamically adjust processing models in response to flex power events.
New algorithms were developed for code bias correction, satellite clock offset estimation, and phase bias modeling, allowing navigation systems to switch seamlessly between normal and flex-power states. The framework also improves ionospheric modeling accuracy by compensating for signal fluctuations that traditional models treat as constant. Validation experiments demonstrated improved continuity and stability in Precise Point Positioning (PPP), confirming that navigation accuracy can be preserved even during active signal power redistribution.
According to the researchers, resilient positioning is becoming essential as satellite systems adopt more adaptive signal strategies. Flex power enhances anti-jamming capability but fundamentally changes signal behavior, meaning traditional static models are no longer sufficient. The team emphasized that detecting flex power in real time and adapting processing algorithms accordingly represents a key step toward next-generation integrated PNT systems. By linking signal monitoring with adaptive estimation, the approach ensures that navigation services remain reliable for both civilian and scientific users operating in challenging electromagnetic environments.
The proposed framework has broad implications for aviation navigation, autonomous transportation, disaster monitoring, and precision timing infrastructure. As GNSS systems increasingly employ adaptive transmission strategies to counter interference, resilient processing methods will be critical for maintaining uninterrupted services. The study's detection and correction strategies could be integrated into global monitoring networks and next-generation GNSS receivers, improving robustness without requiring hardware changes. Beyond GPS and BDS, the methodology may also support future multi-constellation navigation systems, contributing to more secure and dependable global positioning services. Ultimately, the work advances the transition from static navigation models toward adaptive, interference-resilient satellite navigation architectures.
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References
DOI
10.1186/s43020-026-00190-3
Original Source URL
https://doi.org/10.1186/s43020-026-00190-3
Funding information
This research was funded by Scientific Research Key Laboratory Fund (Grant No. SYS-ZX02-2024-01).
About Satellite Navigation
Satellite Navigation (E-ISSN: 2662-1363; ISSN: 2662-9291) is the official journal of Aerospace Information Research Institute, Chinese Academy of Sciences. The journal aims to report innovative ideas, new results or progress on the theoretical techniques and applications of satellite navigation. The journal welcomes original articles, reviews and commentaries.