Lidé na fakultě
Ing. Terézia Pilmannová, MBA

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. 275-281), ISBN 978-80-01-07181-6, ISSN 2694-7854

For decades, records have been kept in the field of air traffic services on every issued ATC clearance based on the service performance directive. There are various information carriers used for this recording. Technological progress has shifted this operation from paper to digital records. This article compares two of the most commonly used methods of recording issued permissions: the traditional method of paper flight strips and the modern stripless system. This research aims to conduct a comprehensive analysis and assess the impact on flight management efficiency emphasizing air traffic controller situational awareness. In the case of the conventional method, it is necessary to monitor more values outside the scope of the situational display, physically move the flight strip holders, located outside the field of view, and tilt the head down. In the second case, the system offers the necessary functions for data entry as an integrated part of the software. Therefore, diverting the view outside the display unit is not necessary. Using both recording methods, an experiment was set up to measure the air traffic controller's situational awareness level. The Situation Awareness Global Assessment Technique (SAGAT) system was used for situational awareness assessment. The research and real life experience indicate, that the stripless recording method has smaller negative impact on situational awareness and is more user friendly. Subjects maintained a better situational overview compared to the paper-based method. This article presents the strengths and weaknesses of individual methods and contributes to the discussion of cognitive functions in air traffic control.

Stať ve sborníku z prestižní konf.

2024, 2024 New Trends in Aviation Development (NTAD), IEEE (Institute of Electrical and Electronics Engineers)), p. 32-37), ISBN 979-8-3315-2774-7, ISSN 2836-2764

As the density of air traffic increases, greater demands are being placed on its efficiency. Various initiatives within Air Traffic Management strive to optimize airspace design and corresponding procedures. Implementing continuous descent and climb operations has the potential to target capacity issues in high-density airspaces while optimizing flight operations to minimize impact on the environment. The underlying research seeks to prove that implementing procedures with vertical profiles positively affects air traffic controllers' workload and, thus, airspace capacity. The research results show that implementing vertical profiles in TMA improved air traffic control efficiency, which was reflected in both a reduction in the total communication time on the frequency and in the decreased number of tasks the controller has to conduct. Therefore, it can be concluded that procedures with vertical profiles can contribute to an efficient utilization of airspace.

Stať ve sborníku z prestižní konf. (Scopus)

2024, Transportation Research Procedia, Amsterdam, Elsevier B.V.), p. 256-265), ISSN 2352-1465

Read-back is a procedure in which a receiving station (flight crew) repeats the received message, or a specific part of it, back to the broadcasting station (Air Traffic Controller) to ensure that the message was received correctly. Incorrect read-back may lead to deviation from the intended clearance issued by the Air Traffic Controller and may only be discovered once the deviation is visible on the radar screen of the Air Traffic Controller. The presented research aims to find methods to design and develop a software tool that would identify wrong read-back in standard phraseology and, notify the Air Traffic Controller. Subsequently, the Automatic Speech Recognition (ASR) software's success rate and test subjects' capability to identify wrong read-back in an experiment is being tested. Results showed that the first iteration of the ASR system, which has not been modified to the specifics of aviation phraseology, reached a success rate of wrong read-back evaluation of 69,9 %. The lowest success rate was recorded for long and complex route clearances. On the other hand, the incorrect read-back detection by the 50 tested subjects reached 95,6 %. The experiment results show that even with limited financial resources, a reasonable transcription success rate can be achieved, given the rapid advances in computing technology and the development of artificial intelligence. Therefore, in terms of detecting wrong read-back, is Automatic Speech Recognition technology is very promising and can significantly improve air traffic safety in the future.

Stať ve sborníku z prestižní konf. (Scopus)

2023, 2023 New Trends in Aviation Development (NTAD), Praha, IEEE Czechoslovakia Section), p. 217-221), ISBN 979-8-3503-7042-3, ISSN 2836-2756

With the ever-increasing demand for air travel, airspace capacity in the vicinity and relative proximity of airports is reaching its limit. With the progressive development of new technologies and their advancement, industry has reached a situation where it is physically possible to have a large number of aircraft in the airspace. Unfortunately, under current operational conditions, reaching these theoretical capacity values is impossible as it is outside human capability to handle such extreme numbers of aircraft safely and efficiently. This limitation is mainly obvious at peak times when runway and sector capacity is at its limit. This article focuses on the capacity of Václav Havel Airport in Prague (LKPR) and the airspace in its vicinity. It presents a proposal to apply a reduced horizontal separation minimum on the final approach phase of instrument flight rules (IFR) flights down to 2.5 NM. Also, it evaluates the impact of this reduction and describes the necessary changes in airport infrastructure, legislation, and air traffic control unit procedures. The implementation proposal is based on the practices at airports abroad with a reduced 2.5NM spacing already applied. The experiments carried out showed that the idea of reduced spacing at LKPR is feasible and brings an increase airspace capacity while maintaining an adequate level of safety. Under ideal conditions and traffic composition, an increase in the number of aircraft handled by more than 10% per hour can be reached.

Stať ve sborníku z prestižní konf. (Scopus)

2023

Dokument představuje výsledek V03 (Poradní a doporučující materiály) projektu Inovativní způsob navigace vrtulníků letecké záchranné služby v České republice s využitím GNSS, postupů Point in Space a tratí Low Level Routes (CK01000031). Výsledek je nezbytnou součástí projektu, jelikož vedle definované koncepce jsou nutné také správné postupy pro její využití a zavedení do praxe. Hlavním přínosem výsledku je snazší a urychlená implementace postupů PinS v ČR.

Výsledky promítnuté do směrnic a nelegisl. předpisů

2023, Human Factors in Transportation, New York, Applied Human Factors and Ergonomics International), p. 539-548), ISBN 978-1-958651-71-1

The work of an Air Traffic Controller (ATCO) involves a constantly changing mental workload and the occurrence of stressful situations to which one must react adequately. Candidates for this profession are expected to demonstrate sufficient resilience and adaptability to such situations already in the selection procedure and during the training process. However, the complexity of Air Traffic Controllers' tasks has increased dramatically in the last decades. A transformation of the ATCO training syllabus was inevitable to ensure the ability of future ATCOs to cope with this changing environment. This change has mainly become apparent in the number of practical skills a trainee has to possess even before initiating the On the Job (OJT) training. Training Organizations are constantly optimizing training processes to prepare a candidate able to withstand challenging situations with varying workloads.To investigate trainees' reactions to increased workload in the context of conducted errors, an experiment was organized examining 30 subjects that participated in a simulator exercise with increasing intensity. The subjects of the experiment were Department of Air Transport students with no particular experience in ATC but considerable knowledge of standards and procedures in air traffic control and familiarity with the simulation environment. It is therefore supposed that the level of skills and knowledge of the subjects are equivalent to student Air Traffic Controllers conducting the basic training. The aim of the experiment was to assess the impact of increased workload, utilizing ECG measurement, on the trainees' performance and subsequent error analyses. The increased workload is achieved by continuously increasing the difficulty of the exercises on the ATC simulator. To analyze, the ECG measurement, data, including R-R intervals, were processed by a short Fourier transform(STFT), filtered and further processed by HRVAS (in Matlab) by time-frequency analysis. Data were processed for Low and High Frequency (individual sympathetic and parasympathetic values). A stress value could be obtained by dividing these two values, which were projectedand plotted against time. Further, error analysis has been conducted, observing 12 categories of errors, including wrong phraseology, application of wrong ATC procedures, separation infringement, and loss of situational awareness. The experiment has shown that the students are prone to conduct mainly errors associated with basic procedures while with time and increasing workload, also errors connected to aircraft separation, situational awareness, and flight efficiency. The results indicate that the most common errors include failure to report aircraft/target identification, failure to confirm ATIS and QNH information for a given airport, descending below the transfer level, failure to respect airspace within vertica

Stať ve sborníku z mezinár. konf.

2023

Cílem této studie je navrhnout koncept provozu (CONOPS postupů PinS a LLR) a příslušnou studii bezpečnosti (Safety Study) umožňující využít přístrojové postupy pro lety vrtulníků (přiblížení, přistání, odlety, traťové lety) v neřízeném vzdušném prostoru a pod minimální výškou pro radarové vektorování, přičemž bude dosahovat akceptovatelné úrovně provozní bezpečnosti. Pro splnění tohoto cíle je třeba využít nejlepší praxi existujících postupů, identifikovat překážky současného prostředí a navrhnout jejich odstranění, definovat základní předpoklady bezpečných postupů, navrhnout koncept provozu pro PinS a koncept provozu pro nízké letové tratě (LLR – Low Level Routes), zhodnotit provozní bezpečnost navržených řešení, provést ekonomickou analýzu zavedení konceptů provozu a zhodnotit provozní přínosy při implementaci konceptů provozu, včetně analýzy dopadů na jiné uživatele vzdušného prostoru.

Oponovaná výzkumná zpráva v češtině

2022, Transportation Research Procedia, Amsterdam, Elsevier B.V.), p. 275-282), ISSN 2352-1457

Proven by accident statistics, a tired pilot poses a threat to safe flight operations, especially in its critical phases, such as the approach to landing. In the context of the fatigue's impact on the accurate execution of the approach to landing, no research has yet been carried out to experimentally confirm/deny the impact of this factor on the pilot's performance. Therefore, this study examines the impact of fatigue on the final approach phase through a 24-hour flight simulator experiment. Eight subjects participated in the study, performing 15 instrument approaches over the time period defined above. In order to quantify the stabilised portion of the approach, a time-based approach was defined. The approach was based on identifying the portion of the approach executed in the prescribed descent region of pyramidal shape expressed in percent. The results show a link between the precision and accuracy of the instrument approach execution and the level of pilot fatigue, which can lead to unstabilised approaches that negatively affect overall safety. Therefore, the experimental setup, methodology, and results can serve as an evidence-based approach for a more concrete definition of fatigue risk management or as a knowledge base for further development of this issue.

Stať ve sborníku z prestižní konf. (Scopus)

2022, 2022 New Trends in Civil Aviation (NTCA), Praha, České vysoké učení technické v Praze), p. 69-73), ISBN 978-1-6654-5190-1

This paper dissertates about utilization of Automatic Dependent Surveillance-Broadcast (ADS-B) parameters Navigation Accuracy Category for Position (NACp) and Navigation Integrity Category (NIC) for possible identification of Global Navigation Satellite Systems (GNSS) jamming. GNSS jamming poses a high-security risk not only for aviation. ADS-B transmitted from most of the aircraft brings a possibility to use the ADS-B to identify the presence of GNSS jamming. Therefore, aircraft are used as detectors to identify jamming presence with wide area coverage. A method for GNSS jamming detection using the correlation of NACp and NIC ADS-B parameters is presented in this article. The results of applying this method on multiple real datasets are shown and discussed.

Stať ve sborníku z prestižní konf.

2020, Transportation Research Procedia, Linz, Elsevier BV), p. 252-260), ISSN 2352-1465

There is a great emphasis on safety in the field of aviation. Advanced technologies open new possibilities and allow objective measurements of specific safety factors. One of these factors is undoubtedly human performance which is already a significant element within a training of aviation personnel. The area of the highest interest is focused on pilot training. The aim of this study is to examine whether a specific psychological training can be considered as a positive performance influencing factor. Subjects underwent an experimental training schedule which was designed for the purpose of this study. Subjects were divided into control (n=20) and experimental (n=20) groups. The experimental group underwent Jacobson progressive relaxation psychological training. Both groups were evaluated during the experimental training schedule; accuracy and precision of piloting was measured during the second and eleventh hour of training. This study focused on basic flight maneuvers, i.e. straight and level flight, 360° horizontal turn with 30° bank and 180° climbing/descending turn with 15° bank and vertical speed of ± 500 ft/min. For the purpose of maneuver identification, Density-based spatial clustering of applications with noise algorithm was used. Each maneuver was evaluated for precision and accuracy and at the same time and used for a performance comparison between groups. Paired and between subject statistical testing were performed using appropriate statistical methods at the level of significance p<0.05. The results indicated that the implemented psychological training did not affect the performance of pilots in terms of precision and accuracy.

Stať ve sborníku z prestižní konf. (Scopus)

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)

2020, 2020 New Trends in Civil Aviation, Praha, IEEE Czechoslovakia Section), p. 111-116), ISBN 978-80-01-06726-0, ISSN 2694-7854

With developing efforts to increase aviation safety, the focus on human factors is being emphasized as well. One of the phenomena affecting the performance of the pilot or other aviation specialists is undoubtedly the fatigue. Dangerous situations can occur, especially when fatigue accumulates. Monitoring fatigue is therefore in the interest of all stakeholders as well as the aviation authorities, which have developed Fatigue Risk Management System. In spite of the fact that the system itself at its highest level also uses the objective data, to this day, the monitoring of fatigue in aviation has mainly been based on a questionnaire survey. Although, the standardized NASA Task Load Index (NASA TLX) is often applied, it remains questionable whether such a questionnaire realistically reflects the fatigue. Based on previously mentioned, the NASA TLX was modified to focus on pilot fatigue and then applied during 24-hour measurements for the purposes of this paper. Eight pilots took part in the measurement, each of them performed 8 simulated flights. From the results of the questionnaire survey, a window of circadian low can be observed, in accordance with the evaluated theta/alpha parameter obtained by spectral analysis of EEG records. The results therefore indicate that such a questionnaire is able to indicate fatigue.

Stať ve sborníku z prestižní konf. (Scopus)

2020, Transportation Research Procedia, Linz, Elsevier BV), p. 243-251), ISSN 2352-1465

Air traffic controllers (ATCOs) are exposed to high workload even during routine operations. Their job carries a lot of responsibility and consists of complex tasks. In order to enhance high safety standards, a systematic evaluation of workload levels is required. This study explores an objective measurement of workload. Heart activity of ATCOs was monitored in order to indicate psychological status of ATCOs while being exposed to different levels of workload - in terms of changing traffic loads and airspace complexity. A standard method was used for the evaluation of heart activity. This method includes the frequency analysis in context of heart rate variability; time intervals of consecutive R waves in the heart activity record are assessed. The evaluation of the ratio of power in the low-frequency and high-frequency bands (indicator of sympathovagal balance) as well as parameters derived from fluctuation analysis were used. The results indicated that parameters of heart rate variability based on spectral analysis were significant in case of workload evaluation.

Stať ve sborníku z prestižní konf. (Scopus)