Automatic Dependent Surveillance-Broadcast System Research Articles

The CanX-7 Nanosatellite ADS-B Mission: A Preliminary Assessment

The development of space-based Automatic Dependent Surveillance-Broadcast (ADS-B) will allow surveillance of aircraft in areas not covered by radar or ground-based ADS-B systems. In September 2016, the Canadian Advanced Nanospace eXperiment-7 (CanX-7) satellite was launched into a 690 km sun synchronous orbit with an ADS-B receiver payload. The first phase of ADS-B data collection took place over the North Atlantic between 4 and 31 October. A preliminary assessment of the data indicates that the average ADS-B signal strength is close to the calculated receiver detection threshold of D94.5 ± 0.5 dBm. The pattern of received ADS-B reception appears to be consistent with a signal propagation model developed for the CanX-7 mission. Future work includes the comparison of coincidental flight plan data for the operations area and an analysis of the payload antenna pattern.

Evaluation of the Capability of Automatic Dependent Surveillance Broadcast to Meet the Requirements of Future Airborne Surveillance Applications

Automatic Dependent Surveillance Broadcast (ADS-B) Out supports various ground applications including Air Traffic Control (ATC) surveillance in radar airspace, non-radar airspace and on the airport surface. In addition, the capability of aircraft to receive ADS-B Out messages from other aircraft within their coverage (ADS-B In) enables enhanced airborne surveillance applications. The requirements of the application vary depending on its safety-criticality. More stringent applications will require higher levels of performance. It is therefore critical that the ADS-B system performance is measured against the most stringent application it is designed for. This paper reviews the various enhanced airborne surveillance applications and the required ADS-B information to support them. It identifies the ADS-B based applications required for Air Traffic Management (ATM) modernisation under the SESAR/NextGen programs. It discusses existing ADS-B Out versions and their capabilities. A mapping exercise is undertaken to assess the credibility of the ADS-B system performance to support the functionalities and requirements of the various enhanced airborne surveillance applications and establish those that require further research and development, highlighting some of the key challenges.

System specifications for developing an Automatic Dependent Surveillance-Broadcast (ADS-B) monitoring system

Automatic Dependent Surveillance-Broadcast (ADS-B) is a surveillance system placed in aircraft that periodically transmits state vector estimates and other information to air traffic control centers and other nearby aircraft (and may also receive traffic and weather information from various entities). The state vector estimates are derived from navigation avionics and are transmitted via a common communications channel, which means that ADS-B is highly dependent on aircraft navigation and communication systems. ADS-B also requires ground stations to receive information from aircraft. As a result of this complex architecture, the ADS-B system is prone to various failure modes.A systematic and comprehensive performance monitoring system is required to ensure the safe use of ADS-B data for air traffic control operations. It is vital that such monitoring systems are in place before a global ADS-B implementation date is mandated by the International Civil Aviation Organization. A number of air navigation service providers and regulators have developed ADS-B performance monitoring methods without a standardized guideline for system specifications. These include Airservices Australia, the U.S. Federal Aviation Administration, EUROCONTROL, the Civil Aviation Authority of Singapore and the Civil Aviation Department of Hong Kong.This paper presents a holistic set of system specifications for ADS-B monitoring systems. In particular, the paper analyzes the ADS-B infrastructure, conducts a systematic review of existing ADS-B monitoring systems, classifies the system characteristics to identify gaps, and derives a set of specifications for developing ADS-B monitoring systems. The paper also assesses the compliance of existing ADS-B monitoring systems against the proposed specifications using a mapping exercise. The system specifications serve as a foundation or minimum requirements for air navigation service providers and original equipment manufacturers to develop systematic and comprehensive ADS-B monitoring systems.

An Approach to Assess the Safety of ADS-B-based Unmanned Aerial Systems: Data Integrity as a Safety Issue

The increasing demand for the use of unmanned aerial systems (UAS) in various social and economic applications has pressed aviation authorities to draw up rules and regulations in order to allow such aircraft to fly in non-segregated airspace. However, issues related to the safety of air traffic operations arise when considering the possibility of both manned and unmanned aircraft coexisting. Thus, surveillance plays a key role in monitoring and controlling air traffic in new scenarios. The positional information provided by the Automatic Dependent Surveillance - Broadcast (ADS-B), originally designed to improve situational awareness for pilots and support controllers in air traffic management, interacts with the Sense and Avoid Systems (S&AS) of the UAS in order to avoid exposure to events of loss of minima separation distances and collisions. As positional information is essential to UASs control systems operation, parameters such as accuracy and integrity reflect the correctness and trustworthiness of this information. This paper presents a qualitative approach to assess safety when using ADS-B systems integrated with UASs in aeronautical operations considering the influence of data integrity as a safety-related parameter. In addition, the possibility of using a methodology previously applied on manned systems for assessing safety on UASs is discussed. A new testing platform (PIpE-SEC) is presented as a possible approach for this safety evaluation.

Safety Benefit of Automatic Dependent Surveillance-Broadcast Traffic and Weather Uplink Services

The automatic dependent surveillance-broadcast system serves a dual role for general aviation operators, allowing integration with modern surveillance systems and providing an uplink of traffic, weather, and airspace information to participating aircraft. To obtain automatic dependent surveillance-broadcast uplink services, aircraft must be equipped with a portable or installed “automatic dependent surveillance-broadcast-in” receiver and display. This study used an online survey to assess pilot perception and valuation of automatic dependent surveillance-broadcast-in traffic and weather services, including flight information system-broadcast and traffic information system-broadcast. Of the 1407 pilot respondents to the survey, 56.3% indicated having used automatic dependent surveillance-broadcast-in traffic and weather services while operating an aircraft. Among pilots who reported using automatic dependent surveillance-broadcast-in traffic services regularly, 64.5% reported that it helped them visually acquire traffic and 42.2% felt that the automatic dependent surveillance-broadcast uplink had provided information that helped prevent a midair collision. A strong link was observed between pilot satisfaction with automatic dependent surveillance-broadcast-in traffic information and concurrent equipage with “automatic dependent surveillance-broadcast out.” Pilots also reported using automatic dependent surveillance-broadcast-in weather and airspace services to improve inflight decision making, such as evaluating options for rerouting, changing altitude, or diverting to alternate airports.

Degarbling Mode S replies received in single channel stations with a digital incremental improvement

Multilateration and automatic dependent surveillance-broadcast systems are used in air traffic control to detect, locate and identify cooperating aircraft using signals emitted by airborne transponders and received by dedicated ground stations. In areas with a high traffic density, these stations may receive simultaneously several superimposed signals. Present operational systems use only one receiving channel connected to a non-directional antenna. When the received replies are superimposed, that is, 'garbled', their detection and/or decoding are severely affected in nowadays equipment. The aim of this study is to transform the single channel problem into a multiple channels problem in order to solve it using specific knowledge about the Mode S signals. In fact, the multiple channels problem is a typical signals separation problem applied to Mode S mixture for which several algorithms already exist. The authors' algorithm, named projection algorithm (PA) single antenna, is based on the existing PA and can be easily implemented on existing receiving stations. The effectiveness of their method is demonstrated using real data collected from their experimental receiver.

ADS-B 서버 시스템의 설계 및 구현

The automatic dependent surveillance - broadcast (ADS-B) system which is a core system of aviation system block upgrade is designed and implemented. The ADS-B system consists of the 4 blocks and 10 units, and filtering algorithm is applied to the implemented ADS-B system. To evaluate a performance of the implemented ADS-B system, real aircraft position data is used and compared reliable radar data. The comparison results show that average position difference of 99.57 m. In addition, comparisons of aircraft position data between the implemented ADS-B system employing filtering algorithm and the conventional ADS-B system under various situations are carried out, such as aircraft turning, taking off, landing, and cruising. The comparison results show that average position difference of 8.02 m.

A safety assessment framework for the Automatic Dependent Surveillance Broadcast (ADS-B) system

The ATM system is currently undergoing various fundamental changes to improve air travel performance. A key change is the transition from a mainly reactive and tactical system to a significantly more predictive and strategic system. This is encapsulated in the concept of 4D trajectory based operations, currently being developed in Europe and the USA through the Single European Sky (SES)/Single European Sky ATM Research (SESAR) and the Next Generation Air Transportation System (NextGEN) respectively. At the core of this transition, is the need for improved situational awareness, shared between relevant stakeholders. The Automatic Dependent Surveillance Broadcast (ADS-B) system is a key enabler of this concept, targeted at distributing real-time positioning and navigation information to stakeholders. Therefore, the safety and credibility of the ADS-B system to support various ground and airborne applications are key, and need to be assessed and validated. This paper reviews existing safety assessment methods, identifies key limitations and proposes a novel, comprehensive and rigorous safety assessment framework for the ADS-B system.

항행시스템 성능향상을 위한 강인한 필터링 알고리즘

CNS/ATM(communication navigation surveillance / air traffic management)의 감시 분야에서는 ADS-B(automatic dependent surveillance - broadcast) 시스템, MLAT(multilateration) 시스템, WAM(wide area multilateration) 시스템이 구축되고 있다. ADS-B, MLAT, WAM 시스템의 항공기 추적 성능이 기존의 레이더에 비해 매우 우수하지만 여전히 오차를 포함하고 있다. 따라서 본 논문에서는 차세대 항행시스템의 오차를 줄이고 항공기 추적 성능을 높일 수 있는 필터링 알고리즘을 제안하였다. 필터링 알고리즘 중에서 가장 유용하다고 알려진 IMM(interacting multiple model) 필터를 개선한 Robust IMM 필터를 사용하였으며, ADS-B, MLAT, WAM 시스템 등의 차세대 항공기 추적 시스템에 적용하였다. Robust IMM 필터는 항공기 추적성능을 향상시킬 뿐만 아니라 항공기 위치 데이터가 손실되더라도 필터에서 계산한 추정값을 이용하여 지속적인 위치 추적을 가능하게 한다. 필터링 알고리즘을 차세대 항행시스템에 적용했을 때 평균 19.21%의 성능향상이 있었다. Among various fields of the CNS/ATM, the surveillance field which includes ADS-B system, MLAT system, and WAM system is implemented. These next generation systems provide superior performance in tracking aircrafts. However, They still have error. In this paper, filtering algorithm is proposed in order to enhance aircraft tracking performance of ADS-B, MLAT, and WAM systems. The proposed method is a Robust Interacting Multiple Model filter, called Robust IMM filter, that improves IMM filter. The Robust IMM filter can not only improves the aircraft tracking performance but also track aircraft continually using estimates calculated from the filter when data losses occur. The simulation results of the proposed aircraft tracking methods show that the filtering data provides a better performance up to an average of 19.21%.

Performance Evaluation and Optimization of Communication Infrastructure for the Next Generation Air Transportation System

Automatic dependent surveillance-broadcast (ADS-B) is one of the fundamental surveillance technologies to improve the safety, capacity, and efficiency of the national airspace system. ADS-B shares its frequency band with current radar systems that use the same 1,090 MHz band. The coexistence of radar systems and ADS-B systems is a key issue to detect and resolve conflicts in the next generation air transportation system (NextGen). This paper focuses on the performance evaluation of ADS-B with existing radar systems and performance optimization of ADS-B systems to improve the safety and efficiency of conflict detection and resolution in NextGen. We have developed a simulation environment which models the complex interplay among the air traffic load, the radar systems, the ADS-B systems, and the wireless channel. A simple model is used to derive an analytical expression for a performance metric of ADS-B. This model is then used to design an adaptive ADS-B protocol for maximizing the information coverage while guaranteeing reliable and timely communication in air traffic surveillance networks. Simulation results show that the effect of ADS-B interference on the current radar system is negligible. The operational ability of ADS-B meets the performance requirements of conflict detection and resolution in air traffic control. However, upgrades are required in the current radar system for operation within an ADS-B environment since the current radars can significantly degrade the ADS-B performance. Numerical results indicate that the proposed adaptive protocol has the potential to improve the performance of conflict detection and resolution in air traffic control.

Design and Implementation of CRC Error Correction for ADS-B System Responding Based on FPGA

Automatic Dependent Surveillance Broadcast (ADS-B) system signal error detection and correction process scheme are introduced in this paper, and the working principle of cyclic redundancy check (CRC) is described. Then, this paper provides an error correction algorithm based on the confidence judgment and an error correction process flow chart based on ADS-B system. Finally, the design of CRC checksum is performed by taking use of Verilog HDL, and the simulation and verification are achieved in Modelism software platform. Experimental results show that the algorithm can carry out verification and error correction for ADS-B responding signal and can improve the reliability of ADS-B system signal transmission.

ADS-B System Failure Modes and Models

Automatic Dependent Surveillance Broadcast (ADS-B) is envisioned to support seamless aircraft surveillance and enhanced air-to-air and air-to-ground applications. ADS-B is an integrated system, dependent on on board navigation systems to obtain aircraft state information as well as a communication data link to broadcast this information to Air Traffic Control (ATC) on the ground and other ADS-B equipped aircraft. To quantify system safety, a good understanding of the potential failure modes of the system is vital. ADS-B system failure modes include those from the communication and navigation systems and human and environmental factors, as well as ADS-B-specific components. In this paper, potential failure modes of the ADS-B system are identified using an approach developed in this paper. The end output of the approach is an ADS-B failure mode register. However, the approach is transferable to other ATC surveillance systems. The paper further provides the failure classification and modelling, and also analyses the failure modes' impact on ATC operations and finally proposes potential mitigations. It is important to note that the work carried out in this paper is based on the assumption that the ADS-B operates as the primary surveillance source for the ATC.

EBAA: An efficient broadcast authentication scheme for ADS-B communication based on IBS-MR

Automatic dependent surveillance-broadcast (ADS-B) systems can broadcast satellite-based aircraft position, identification, etc., periodically, and are now on track to replace radar to become the backbone of next-generation air traffic management (ATM) systems. However, ADS-B systems suffer severe cyber-security problems due to the broadcast-type data link and the lack of designed-in security measures. Especially, since ADS-B messages are unauthenticated, it is easy to insert fake aircraft into a system via spoofing or insertion of false messages. Unfortunately, the authentication for ADS-B messages has not yet been well studied. In this paper, based on identity-based signature with message recovery (IBS-MR), an efficient broadcast authentication scheme for ADS-B messages is proposed. The security analysis demonstrates that the scheme can achieve authenticity and integrity of ADS-B broadcast messages, as well as adaptive evolution of broadcasters’ private keys. The performance evaluation shows that the scheme is computationally efficient for typical avionics devices with limited resources. Furthermore, the scheme achieves low communication overhead since broadcast messages can be recovered from signatures, and thus it is suitable for low-bandwidth ADS-B data link.

Hybrid Communication Protocols and Control Algorithms for NextGen Aircraft Arrivals

Capacity constraints imposed by current air traffic management technologies and protocols could severely limit the performance of the Next Generation Air Transportation System (NextGen). A fundamental design decision in the development of this system is the level of decentralization that balances system safety and efficiency. A new surveillance technology called automatic dependent surveillance-broadcast (ADS-B) can be potentially used to shift air traffic control to a more distributed architecture; however, channel variations and interference with existing secondary radar replies can affect ADS-B systems. This paper presents a framework for managing arrivals at an airport by using a hybrid centralized/distributed algorithm for communication and control. The algorithm combines the centralized control that is used in congested regions with the distributed control that is used in lower traffic density regions. The hybrid algorithm is evaluated through realistic simulations of operations around a major airport. The proposed strategy is shown to significantly improve air traffic control performance under various operating conditions by adapting to the underlying communication, navigation, and surveillance systems. The performance of the proposed strategy is found to be comparable to fully centralized strategies, despite requiring significantly less ground infrastructure.

Enabling Confidentiality for ADS-B Broadcast Messages Based on Format-Preserving Encryption

The automatic dependent surveillance-broadcast (ADS-B) system is the backbone of the next-gen air traffic control (ATC) modernization plan. Unfortunately, ADS-B system suffers from serious cyber-security vulnerabilities due to the open broadcast of aircraft data, without regard to message confidentiality. However, using common encryption scheme to provide confidentiality of ADS-B data is not a good solution, because encrypting data with ordinary cryptosystem would violate the original openness intention of ADS-B system design. In this paper, based on the new format-preserving encryption (FPE), we present an efficient data encryption scheme for the ADS-B data. The security analysis demonstrates that our scheme can achieve confidentiality of ADS-B data. The performance evaluation shows that the scheme is computationally efficient for the typical avionics devices with limited resources.

Flight Test Results of a Measurement-Based ADS-B System for Separation Assurance

ABSTRACT: Future Aircraft Surveillance Applications (ASA) systems for situational awareness applications (e.g.,conflict detection and resolution, final approach and runway occupancy awareness, and airport surface situationalawareness methods), airborne spacing applications, airborne separation applications, and self-separationapplications will benefit from the introduction of Automatic Dependent Surveillance-Broadcast (ADS-B). Analternative ADS-B implementation, which transmits measurements from the Global Navigation SatelliteSystem (GNSS) instead of aircraft state vectors and performance parameters in the current implementation, hasbeen proposed previously to improve surveillance performance. This paper summarizes the proposedmethodology, discusses its threat models and integrity aspects, and presents the initial flight test results of thisalternative ADS-B implementation, along with a performance analysis. Copyright # 2013 Institute of Navigation INTRODUCTIONTo meet the expanding demand of air traffic in theNational Airspace System (NAS), an increase incapacity will be required. Efforts to achieve thischange in capacity are directed and overseen bythe Joint Planning and Development Office (JPDO)formed by the Federal Aviation Administration(FAA), the National Aeronautics and SpaceAdministration (NASA), and several othergovernment agencies. The resulting improved airtransportation system is referred to as the NextGeneration Air Transportation System or NextGen.When completed NextGen is supposed to “providethe capacity required to meet the nation’sneedinthemost effective, efficient, safe, and secure mannerpossible” [1, 2]. Meanwhile, Europe has been workingon an equivalent transformation of European airspace through the Single European Sky Air TrafficManagement (ATM) Research (SESAR) [3].The goals of NextGen are to significantly increasethe safety, security, capacity, efficiency, andenvironment compatibility of aviation operations inthe NAS. In order to achieve increased capacityand efficiency in an even more congested NAS, manydecisions in NextGen will be made at a local levelwith an awareness of system-wide implications.Intermsofsurveillance,NextGenenvisionsdelegatedseparation, which transfers certain responsibilityfor separation from ATM to flight crews to ensurethat the applicable airborne separation minimaare met. In particular, two of the eight identi fiedkey capabilities of NextGen, Performance-BasedOperations and Services (PBO) and Aircraft Trajectory-Based Operations (TBO), will help facilitate aircraftusingtheir4-Dflightprofilesandperformance-relatedparameters to enable reduced separation andincreased trajectory predictability [1].The Aircraft Surveillance Applications (ASA)systems are expected to provide the abovementionedimproved situational awareness. As the surveillanceand application-specific component of the ASAsystems, Airborne Surveillance and SeparationAssurance Processing (ASSAP) is intended tointegrate information from all the NextGenCommunication, Navigation, and Surveillance (CNS)systems to perform surveillance applicationssuch as enhanced visual acquisition, conflictdetection and resolution, airport surface situationalawareness, final approach and runway occupancyawareness, and enhanced visual approach, and topresent trafficstateinformationtoflight crewsthrough a Cockpit Display of TrafficInformation(CDTI) atleastseveralminutesaheadofapredictedloss of separation [4, 5].

A-GR: A novel geographical routing protocol for AANETs

With the rapid growth of general aircraft and lack of ground facilities, air traffic control and aeronautical communication system face huge pressure, especially in low-altitude airspace. Aeronautical ad hoc networks (AANETs) are large scale multi-hop wireless network of aircraft, which could provide direct air-to-air communication between aircraft without ground infrastructures. However, the features of aircraft node present a great challenge to provide efficient and reliable data packet delivery in AANETs. In this paper, we present an Automatic dependent surveillance-broadcast (ADS-B) system aided geographic routing protocol (called A-GR) for AANETs. The proposed A-GR uses the position and velocity of aircraft provided by airborne ADS-B system to eliminate the traditional routing beaconing and presents a velocity-based metric for next hop selection, which could adaptively cope with the fast moving of aircraft and dynamic changes of network topology. Many simulations are performed and the results show that the proposed A-GR can effectively decrease the routing overhead, improve the packet delivery ratio and make good use of the network resources.

Tracking of Noncooperative Airborne Targets Using ADS-B Signal and Radar Sensing

As the Automatic Dependent Surveillance-Broadcast (ADS-B) system has gained wide acceptance, additional exploitations of the radioed satellite-based information are topics of current interest. One such opportunity includes the augmentation of the communication ADS-B signal with a random biphase modulation for concurrent use as a radar signal. This paper addresses the formulation and analysis of a suitable noncooperative multitarget tracking method for the ADS-B radar system using radar ranging techniques and particle filter algorithms. In addition, the low-update-rate measurement due to the ADS-B system specification is discussed in order to provide acceptable estimation results. Simulation results show satisfactory tracking capability up to several kilometers with acceptable accuracy.

Automatic Dependent Surveillance-Broadcast Training: Does it exist in Collegiate Aviation?

One of the key elements to NextGen is the transition from the current ground- based radar monitoring system to a satellite-based system using the Automatic Dependent Surveillance-Broadcast System (ADS-B). The FAA has set a mandate which requires all aircraft to be ADS-B equipped by the year 2020 in order to continue operating in the National Airspace System. However, the FAA has not set forth any training requirements for aviation instructors or designated examiners. This study looked at how ADS-B is currently being taught among aviation educators across the United States and how important this training is to current aviation curriculum. With the information collected, it was determined that only a minimal amount of ADS-B training is currently taking place across the country, and the training that is taking place is non-standardized and limited due to the perception that ADS-B is only to be used as a traffic advisory tool. There was significant difference in the perceived importance of ADS-B, t(73) = -2.79, p < .01 between the flight instructor group and the group containing mostly professors and administrators. Also, a significant difference was found in the comparison of perceived importance and institution, t(73) = -3.11, p < .01. There was no significance found when comparing the perceived importance of ADS-B training to the number of years a respondent had worked as an aviation educator, F(1,73) = .44, p = .508 or the number of hours a respondent had received ADS-B training, F(1,60) = .15, p = .699. There was also no significant difference in the perceived importance of ADS-B training dependent upon if participants operated in a geographic location that had ADS-B coverage, t(73) = -1.88, p = .063. Several factors were discovered as to why there seems to be no current urgency among aviation educators to train their students in this new technology. In addition, recommended steps the FAA could take in order to help aviation educators with the ADS-B training process were suggested.

Application of Automatic Dependent Surveillance-Broadcast in the Training for Air Traffic Controller

The application of Automatic Dependent Surveillance-Broadcast (ADS-B) in the training for air traffic controller is investigated in the presented work. ADS-B is a surveillance technology for tracking aircraft as part of the Next Generation Air Transportation System (NextGen). Compared to radar, ADS-B system has many advantages such as lower deployment cost, higher accuracy and more frequently update. As surveillance method transits from radar surveillance to ADS-B surveillance, the training for air traffic controller should incorporate ADS-B system correspondingly. In the presented work, the features of ADS-B are introduced as well as the structure of ADS-B system is illustrated, and a novel framework for training air traffic controller with ADS-B system is proposed. It is seen that air traffic controller can be trained with lower cost, shorter period and more flexibility compared to that with radar surveillance.