Lidé na fakultě
Ing. Jakub Steiner

2025, The Aeronautical Journal, 2025 (1), ISSN 2059-6464

The presented research investigates the impact of interference on the performance of aircraft Global Navigation Satellite System (GNSS) receivers with a specific focus on the behaviour of Automatic Dependent Surveillance-Broadcast (ADS-B) position quality indicators. Several experiments were performed with different aircraft types, such as Airbus, Boeing, Beechcraft King Air B350 or Tecnam, and using various intensities of GNSS jamming. The behaviour of various quality indicators, such as the Navigation Integrity Category, Navigation Accuracy Category, Source Integrity Level and System Design Assurance transmitted in different types of ADS-B messages, is analysed. We investigate not only situations where the quality indicators drop to zero, but also the complete evolution of the changes in the indicators as a function of the increasing power of the jamming signal. Based on the analysis of changes in the ADS-B quality indicators, the estimation of the most likely interference signal power required to discontinue the tracking of an already acquired GPS L1 Coarse/Acquisition signal is made. Additionally, the interference signal power to prevent re-acquisition is also estimated. The findings improve the understanding of interference effects and can support the development of robust interference mitigation techniques in aviation applications.

Článek v periodiku excerpovaném SCI Expanded

2024, New Trends in Civil Aviation: Proceedings of the 24th International Conference on New Trends in Civil Aviation 2024, Praha, České vysoké učení technické v Praze), p. 213-218), ISBN 978-80-01-07182-3, ISSN 2694-7854

The paper investigates the impact of spoofing in the form of meaconing on the performance of aircraft Global Navigation Satellite System (GNSS) receiver and ground mobile positioning transmitter that is commonly used for tracking of non-transponder equipped targets on the airport's surface. The interference scenarios were twofold, first consisting of GNSS L1 meaconing with increasing power levels and second with GNSS L1 jamming followed up by meaconing. The impact was investigated by analysing the changes in positional information and position quality indicators transmitted by the Automatic Dependent Surveillance–Broadcast System. Due to the high dependence of aviation on the use of Global Positioning System, meaconing represents a serious security risk. Thus, the knowledge of the resilience of individual systems is key information in specifying response procedures and countermeasures.

Stať ve sborníku z prestižní konf.

2024, New Trends in Civil Aviation: Proceedings of the 24th International Conference on New Trends in Civil Aviation 2024, Praha, České vysoké učení technické v Praze), p. 207-212), ISBN 978-80-01-07181-6, ISSN 2694-7854

Global Navigation Satellite Systems (GNSS) are a key source of position, navigation, and timing for Unmanned Aircraft Systems. This holds true for the new e-ID technology as well, which is compulsory for drones operating in the SPECIFIC category since 2024. Both portable and embedded e-ID devices are a new addition to the market as a reaction to the new legislation. However, these electronic visibility enablers may be susceptible to GNSS interference, possibly leading to denial of service or false position and time information being reported. To assess the vulnerability of these newly introduced e-ID devices, two of them were subjected to a series of GNSS interference attacks. The testing included jamming-only attacks, spoofing-only attacks and attacks combining jamming with subsequent spoofing. The results show the impact of all these attacks on the position and time information, the number of satellites in view and other parameters. Additionally, the results highlight the differences between a GNSS-only e-ID device and an e-ID device with both GNSS and inertia sensors. Finally, the potential of using accuracy indicators in e-ID messages for GNSS interference detection is discussed.

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2024, The Aeronautical Journal, 1331 (129), p. 206-223), ISSN 2059-6464

The threat of GNSS interference poses a great danger to many critical infrastructure systems including air navigation. With a focus on mitigating this threat, this paper proposes a methodology for detecting GNSS interference. The methodology utilises the quality indicator NACp transmitted in ADS-B messages and GPS almanac data for interference detection. The NACp indicator enables estimation of the position error derived from GPS, which is compared with the HDOP value of the GPS satellite constellation. Based on this comparison, the developed detection algorithm determines whether the aircraft is affected by jamming. The detection methodology is evaluated on datasets obtained during deliberate experiments with GPS jamming. The proposed methodology provides a way to detect GNSS interference, facilitating mitigation of its impact on air traffic operation.

Článek v periodiku excerpovaném SCI Expanded

2024, Transportation Research Procedia, Amsterdam, Elsevier B.V.), p. 328-336), ISSN 2352-1465

Global Navigation Satellite Systems (GNSS) have become integral to modern aviation, providing essential positioning, navigation, and timing information. However, the increasing reliance on GNSS has made aviation systems vulnerable to radio frequency interference, particularly intentional jamming. This study compares the effectiveness of Automatic Dependent Surveillance-Broadcast (ADS-B) and a professional GNSS interference detector in identifying jamming at Václav Havel Airport Prague. Over a period of one year, 71,417 flights were analysed, and 37 instances of GPS interference were detected using ADS-B data. Eleven of these instances were also detected by the professional detector, highlighting the potential of ADS-B as a supplementary tool for detecting GNSS interference. This research contributes to the ongoing efforts to enhance the resilience of aviation operations against GNSS jamming.

Stať ve sborníku z prestižní konf. (Scopus)

2024, Neural Network World, 34 (6), p. 341-360), ISSN 2336-4335

Global Navigation Satellite Systems are a critical positioning, navigation, and timing source for various industries. However, their weak signal on Earth’s surface makes them vulnerable to jamming. This paper explores the use of machine learning image recognition for categorizing GNSS jamming signals. The study uses data from a long-term monitoring campaign, with over 2,000 jamming events recorded. Seven commonly used jamming signal types were analyzed using the Residual Neural Networks (ResNet). Five different ResNet models with 18 to 152 layers were evaluated, with the best performing achieving a precision greater than 90% in determining the correct jamming signal category.

Článek v periodiku excerpovaném SCI Expanded

2024, Sborník příspěvků 22. mezinárodní vědecké konference „Měření, diagnostika, spolehlivost palubních soustav letadel“, Brno, Univerzita obrany, Fakulta vojenských technologií), p. 115-121), ISBN 978-80-7582-515-5

Článek popisuje chování letadlového přijímače GNSS a mobilního mechanizačního prostředí vybaveného SQUID v prostředí kde je vysílán falešný signál GNSS (meaconing). Během popisovaných experimentů se podařilo u obou zařízení podvrhnout jejich polohu. V článku je diskutována potřebná úroveň meaconing signálu kdy ke změně polohy došlo. Dále je v článku rozebrána dopad spoofingu signálu na ADS-B parametry kvality, které letadlo i SQUID vysílají pomocí.

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2023, Proceedings of the 36th International Technical Meeting of the Satellite Division of The Institute of Navigation (ION GNSS+ 2023), Manassas, VA, The Institute of Navigation (ION)), p. 4145-4152), ISBN 978-0-936406-35-0, ISSN 2331-5954

The growing dependence of critical infrastructure on Global Navigation Satellite Systems (GNSS) as an accurate and reliable positioning, navigation and timing (PNT) source gives rise to the importance of GNSS interference detection. Although jamming detection capabilities are present in the current market, predominately in the form of specialised GNSS interference detectors or GNSS receivers add-ons. These provide a limited coverage area and their implementation into critical infrastructure operations is rather slow. Therefore, this paper focuses on the detection of GNSS interference using widespread Automatic Dependent Surveillance-Broadcast (ADS-B) technology. The research builds upon previous work and addresses some of its limitations by developing a discrete mathematical model for GNSS jamming detection based on ADS-B quality parameters. To develop and validate the model, a series of experiments involving GNSS jamming in live-sky environments were conducted. The controlled experiments enabled close monitoring of the aircraft navigation systems allowing for precise determination of the aircraft’s jammed/unjammed status. Approximately 75% of the jamming experiment data was used for model development and tuning, while the remaining 25% was reserved for evaluation. The model evaluation leveraging the confusion matrix showed a positive jamming detection rate of over 99% and a false positive jamming detection rate of under 1%. Additionally, the model was tested on ADS-B data from the Atlantic Ocean where no GNSS jamming is expected. Using this data set the model exhibited an under 1% false positive jamming detection rate.

Stať ve sborníku z prestižní konf. (Scopus)

2023, Engineering Proceedings, European Navigation Conference ENC 2023, Basel, MDPI), p. 1-10), ISSN 2673-4591

GNSS is an indispensable source of positioning, navigation and timing for many sectors including inland waterway transport. Unfortunately, GNSS is also vulnerable to interference including intentional jamming and spoofing. This paper evaluates the vulnerability to GNSS jamming and spoofing of one of the key inland waterway systems – the automatic identification system (AIS). The vulnerability is explored via a series of tests conducted in both laboratory and live-sky environments. The results clearly show the negative impact of both types of interference on AIS. The impact included denial of service and reporting of false position. Additionally, the effects on subsequent systems like the river information services or nearby vessels are also showcased. The results presented provide valuable inside into the vulnerability of inland waterway transport. The need for understanding the system limitations and vulnerability raises with the increase of implementation of autonomous systems into the inland waterway sector, as well as other critical infrastructure sectors.

Stať ve sborníku z prestižní konf. (Scopus)

2022, 2022 New Trends in Civil Aviation (NTCA), Praha, České vysoké učení technické v Praze), p. 51-55), ISBN 978-80-01-06985-1, ISSN 2694-7854

Global Navigation Satellite Systems (GNSS) are a key source of position, navigation, and timing in safety critical domains, including aviation. Due to GNSS low signal power when received on Earth's surface the signal is very susceptible to unintentional and intentional jamming. To assess the criticality of GNSS jamming, a long-term monitoring campaign was carried out near airport infrastructure and near highways using verified GNSS jamming detectors on the L1 frequency. The results show a frequent occurrence of GNSS jamming near airport infrastructure due to the illegal use of jammers on board of road traffic with more than 6 events per day with expected impact on GNSS signal reception. The results and their importance and implications are discussed. The results also show a very disturbing occurrence of a wide-area GPS jamming of the L1 frequency detected throughout Europe possibly impacting more than 1 million kilometers squared of area. The impact and possible causes of this phenomenon are discussed.

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2020, 2020 New Trends in Civil Aviation, Praha, IEEE Czechoslovakia Section), p. 123-128), ISBN 978-80-01-06726-0, ISSN 2694-7854

The ADS-B system is one of the key pillars of the future surveillance infrastructure, where the provided position information is predominantly dependent on the availability and quality of GNSS position information. The article presents the findings obtained during a real-time measurement in which the GNSS receiver within the multi-mode receiver (MMR) on the B737 MAX was interfered. In addition to identifying the power level sufficient to disable the GNSS receiver on this aircraft, the article further describes the behavior of the ADS-B system under jamming conditions. The experiment was performed on the ground, i.e., both the aircraft and the jammer were stationary during all phases of measurement.

Stať ve sborníku z prestižní konf. (Scopus)