Communication, Navigation, Surveillance And Air Traffic Management Research Articles

Ionospheric Effect on Global Navigation Satellite System Performance - A Review

Satellite-based Communication, Navigation, Surveillance and Air Traffic Management (CNS/ATM) systems have been adopted by the international aviation community to meet the challenges of continuously rising global air traffic. Global Navigation Satellite System (GNSS) has been prescribed for the provision of navigation services to the air traffic. Performance of GNSS depends upon many factors including refraction and scintillation effects of ionosphere on the satellite signals. Severity of this effect depends largely upon the geographical location of the navigation receiver, the time of the day, the month of the year and the year on the 11-year solar cycle. This paper studies ionosphere mechanism and discusses its effect on the performance of GNSS. The paper also predicts the performance during solar cycle maximum expected in 2013-2014 [Jensen, Anna B.O., Mitchell, Cathryn 2011]. It touches upon the preparations going on to face the adverse effects of increased solar activity during the cycle maximum and recommends coordination/cooperation between various relevant organizations/institutions in the processes of data collection and development of a model.

효율적인 다중 버전 ADS-B 타깃 리포트 메시지 처리를 위한 모듈 설계 및 구현

ADS-B (automatic dependent surveillance-broadcast)는 차세대 항행시스템 CNS/ATM (communication, navigation and surveillance/air traffic management)의 핵심기술로 위성항법시스템 정보를 이용하여 자신의 위치 정보를 자동으로 방송하며, 기존 레이더 시스템에 비해 지형에 의한 제약이 적고 갱신 속도가 빠르다는 장점을 가지고 있다. EUROCONTROL에서는 항공관제시스템에서 ADS-B 메시지를 교환하기 위하여 표준 감시자료 포맷 ASTERIX (all purpose structured eurocontrol surveillance information exchange) CAT.021을 정의하였다. 그러나 ASTERIX CAT.021은 업데이트 주기가 빠르고 이전 버전과 호환이 되지 않는 문제가 있다. 본 논문에서는 ASTERIX CAT.021의 버전과 관계없이 효율적으로 메시지를 처리하는 모듈을 설계 및 구현하였다. 구현 모듈은 네트워크로부터 수신한 메시지를 수집하여 패턴을 생성하고, 이후 수신 메시지는 패턴에 따라 정의된 루틴으로 처리한다. Automatic dependent surveillance-broadcast (ADS-B) is the core technology of communication, navigation and surveillance/air traffic management (CNS/ATM), automatically broadcasts its own position information using GNSS and has an advantage of lower geological constraints and faster update speed compared with legacy radar systems. EUROCONTROL defined all purpose structured eurocontrol surveillance information exchange (ASTERIX) CAT.021. ASTERIX CAT.021 is modified several times, but it has compatibility issues with previous version of it. In this paper, we have designed an efficient message processing module regardless of the version of ASTERIX CAT.021. This implemented module generates patterns to collect messages received from the network, after that, received messages are processed in the routine that is defined in accordance with the patterns.

Performance analysis of the use of ADS-B for the alternative positioning navigation and timing

The global positioning system (GPS) is the core element of the next-generation communication, navigation, surveillance, and air traffic management (CNS/ATM) system. However, GPS signals are vulnerable to radio-frequency interference (RFI), which can significantly impact the normal operation of the CNS/ATM system. In order to maintain CNS/ATM system operation during GPS outages and to meet safety requirements, an alternative positioning, navigation and timing (APNT) based on a radio link of the automatic dependent surveillance-broadcast (ADS-B) can be used. This study first evaluates two navigation algorithms for an ADS-B radio link, and the real aircraft ADS-B data collected at the civil aviation authorized ground stations are used to evaluate the positioning performance of the proposed backup aviation navigation and surveillance system. In addition, the main factor affecting the positioning performance of the radio navigation system is the geometric distribution of ground stations. Therefore, the geometric distribution of the actual ADS-B ground stations in the CNS/ATM system is evaluated using horizontal dilution of precision for a specific flight information region. Overall, the results of the actual flight data show that it is highly feasible to apply the ADS-B radio link as an APNT solution.

Multi-Sensor Fusion with Interacting Multiple Model Filter for Improved Aircraft Position Accuracy

The International Civil Aviation Organization (ICAO) has decided to adopt Communications, Navigation, and Surveillance/Air Traffic Management (CNS/ATM) as the 21st century standard for navigation. Accordingly, ICAO members have provided an impetus to develop related technology and build sufficient infrastructure. For aviation surveillance with CNS/ATM, Ground-Based Augmentation System (GBAS), Automatic Dependent Surveillance-Broadcast (ADS-B), multilateration (MLAT) and wide-area multilateration (WAM) systems are being established. These sensors can track aircraft positions more accurately than existing radar and can compensate for the blind spots in aircraft surveillance. In this paper, we applied a novel sensor fusion method with Interacting Multiple Model (IMM) filter to GBAS, ADS-B, MLAT, and WAM data in order to improve the reliability of the aircraft position. Results of performance analysis show that the position accuracy is improved by the proposed sensor fusion method with the IMM filter.

Simulation in CNS/ATM research with examples from the United States

Technology advances, particularly in computer hardware and software, have made simulation an essential tool in Communications, Navigation, and Surveillance/Air Traffic Management (CNS/ATM) research and development. Both real and fast time simulations find use in applications ranging from early concept exploration to pre-operational laboratory testing. ATM research labs throughout the world are making common use of these tools. They range from relatively small-scale labs at universities to costly high fidelity cockpit and ATC simulators at major government labs, such as NASA Ames Research Center. Networked simulators are making it possible to study the complex interactions of numerous actors (computers and people), possibly with new roles, in future ATM systems.