Automatic Dependent Surveillance-Broadcast System Research Articles

Independently convolutional gated recurrent neural unit for space-based ADS-B signal separation with single antenna

Automatic Dependent Surveillance-Broadcast (ADS-B) is a critical technology to transform aircraft navigation by improving safety and overall effectiveness in the aviation industry. However, overlapping of ADS-B signals is a large challenge, especially for space-based ADS-B systems. Existing traditional methods are not effective when dealing with cases that overlapped signals with small difference (such as power difference and carrier frequency difference) require to be separated. In order to generate an effective separation performance of the ADS-B signals by exploring its temporal relationship, Independently Convolutional Gated Recurrent Neural Unit (Ind-CGRU) is presented for encoder–decoder network construction. Experimental results on the dataset SR-ADSB demonstrate that the proposed Ind-CGRU achieves good performance.

Construction of a model of steganographic embedding of the UAV identifier into ADS-B data

Secure data exchange in the control system of unmanned aerial vehicles (UAVs) is an important aspect for preventing unauthorized access and safety of aerial vehicles. Given the problems of automatic dependent surveillance-broadcast (ADS-B) data protection, the safety level of UAV flight tasks and air traffic in general is significantly reduced. Therefore, the protection of ADS-B data is an urgent task. The object of the study is the process of steganographic protection of ADS-B format data. A relevant problem of estimating the probabilistic time characteristics of the steganographic protection process is solved, taking into account the features of data embedding in the ADS-B format container. To solve it, a mathematical formalization of the methods of finding probabilistic-temporal characteristics of steganographic systems was carried out. A model of steganographic data transformation operations based on the Chinese remainder theorem has been built. The main difference of the model is taking into account the features of the ADS-B format data. This made it possible to formalize and evaluate the time functions of steganographic encoding and decoding of UAV identifiers with an integrated ADS-B system. A model of steganographic data transformation operations based on the finite integral ring theorem has been constructed. A list of operations performed in the developed algorithm has been compiled. This made it possible to carry out mathematical formalization of operations for complex use in the model of steganographic protection of UAV identifiers with a built-in ADS-B system. The mathematical model was studied and the estimation of the random value of the time of steganographic transformation of data, as well as the confidence interval, was performed. With the help of the reported set of models, it is possible to estimate the probability of the algorithm’s execution time falling within the given interval. The results of the calculation of probabilistic-time characteristics could be used in models of a higher level of the hierarchy

Optimization of digital multi-beamforming for space-based ADS-B using distributed cooperative coevolution with an adaptive grouping strategy

Space-based Automatic Dependent Surveillance-Broadcast (ADS-B) technology can eliminate the blind spots of terrestrial ADS-B systems because of its global coverage capability. However, the space-based ADS-B system faces new problems such as extremely low Signal-to-Noise Ratio (SNR) and serious co-channel interference, which result in long update intervals. To minimize the position message update interval at an update probability of 95% with full coverage constraint, this paper presents an optimization model of digital multi-beamforming for space-based ADS-B. Then, a coevolution method DECCG_A&A is proposed to enhance the optimization efficiency by using an improved adaptive grouping strategy. The strategy is based on the locations of uncovered areas and the aircraft density under the coverage of each beam. Simulation results show that the update interval can be effectively controlled to be below 8 seconds compared with other existing methods, and DECCG_A&A is superior in convergence to the Genetic Algorithm (GA) as well as the coevolution algorithms using other grouping strategies. Overall, the proposed optimization model and method can significantly reduce the update interval, thus improving the surveillance performance of space-based ADS-B for air traffic control.

Security Establishment in ADS-B by Format-Preserving Encryption and Blockchain Schemes

In the next generation modernization plan, the automatic dependent surveillance-broadcast (ADS-B) system plays a pivotal role. However, the ADS-B’s low level of security and its vulnerabilities have raised valid concerns. The main objectives of this paper are to highlight the limitations of legacy ADS-B systems and to assess the feasibility of using Format-preserving (F), Feistel-based encryption (F), with multiple implementation variances (X) (FFX) algorithms, for enhancing ADS-B’s security. The offered solution is implemented in a standard software-defined radio (SDR) ADS-B to be utilized in real-time applications. Furthermore, a new proposed blockchain scheme is used as a secured database to manage the cipher key. The metric of message entropy is used to assess an algorithm’s ability to confuse and diffuse predictable ADS-B messages; correlation and serial correlation of plain data and cipher data are deployed to evaluate the proposed method’s security level. The authors provide both MATLAB simulations and flight test outcomes to demonstrate the feasibility of this approach. Based on our security analysis, ADS-B information can be kept confidential through our scheme. The performance evaluation results reveal that the proposed scheme is achievable, compatible, and efficient for the avionics industry.

Modernizacija i kontrola vazdušnog saobraćaja - implementacija ADS-B sistema 2022 - pregled

Automatic Dependent Surveillance-Broadcast (ADS-B) is a multiparameter surveillance system designed to improve key segments of air traffic: enabling real-time surveillance, raising safety and efficiency levels, and improving flight information and weather services. ADS-B consists of two subsystems, ADS-B Out and ADS-B In. Although only a complete system, ADS-B In/Out provides numerous benefits (additional situational awareness, more efficient oceanic routing, etc.) FAA and EASA only require ADS-B Out (by January and June 2020, respectively), whereby ADS-B In remains optional. Because of its many advantages, ADS-B In/Out will be popular, but there are some weaknesses, which are primarily related to its cyber vulnerabilities due to insufficient authentication and encryption in the applied protocol. In this paper, an overview of the ADS-B system is presented as an aid to understanding the security problems and the different ways of potential attack. In addition, this review deals with the current state of ADS-B deployment and its future perspective and challenges.

Performance Evaluation of Pulse Position Modulation Scheme in Automatic Dependent Surveillance Broadcast System

this paper presents a new formula for calculating the Bit Error Rate (BER) and the Packet Error Rate (PER) for binary pulse position modulation scheme which had been used in Automatic Dependent Surveillance Broadcast (ADS-B) system, ADS-B system is used in air traffic surveillance and control. ADS-B system uses the Binary Pulse Position Modulation (BPPM) scheme in the link between the aircraft and the ground station. The results show that the simulated bit-error rate and packet error rate are approximately matches the theoretical one; these results have been obtained for both coherent and non-coherent detection. As a result, mathematical formulas to represent the probability of error for BPPM are also derived for both coherent and no-coherent detection scheme.

Handover Strategy Based on Side Information in Air-Ground Integrated Vehicular Networks

The development of the Internet of Things (IoT) and smart cities, combined with the widespread usage of cooperative or independent air traffic surveillance systems such as automatic dependent surveillance-broadcast (ADS-B) bring about novel deployment paradigms in air-ground integrated vehicular networks (AGVN). Therefore, how to make full use of infrastructures, which represented by high altitude platform station (HAPS), and can be orchestrated according to fully use information like ADS-B message, becomes the imminent problem that should be solved. In the view of above problems, in this paper, we propose a novel handover strategy based on side information of the ADS-B for AGVN. Firstly, a practical scenario which use single HAPS as air base station to assist cellular network with multiple users is proposed. Secondly, according to the surveillance platform, side information such as the location, speed, and realtime throughput of HAPS is obtained by all the static base stations using ADS-B system. Thirdly, a modified handover strategy over HAPS based on the side information is used to enhance the service ability of all the network. Simulation results show the fully use of side information can increase the capacity of the AGVN.

Hybrid N-Inception-LSTM-Based Aircraft Coordinate Prediction Method for Secure Air Traffic

With the rapid growth of the number of flights, the traditional radar system has been unable to meet the needs of flight supervision. At the same time, it also puts forward higher requirements for air traffic management (ATM). Automatic dependent surveillance-broadcast (ADS-B) is a promising technology in the next generation of air traffic control (ATC). However, the openness of ADS-B system brings the opportunities for terrorists to tamper with data. In this paper, we propose a novel aircraft coordinate prediction hybrid model based on deep learning. The proposed model combines inception modules and long short-term memory (LSTM) modules. Inception modules are used to extract the spatial features of dataset, and LSTM modules are used to extract the temporal features of dataset. In addition, we use the ADS-B signal strength instead of its specific information to obtain aircraft coordinates. Signal strength is not easily tampered with, but it carries limited information. Therefore, this scheme sacrifices a certain precision for reliability. Inception modules and LSTM modules are combined in different ways to perform experiments on the real-world ADS-B datasets from OpenSky network. The experimental results show that the proposed 2-Inception-LSTM is the local optimal model. The prediction error is within 10 km. It can be suitable for situations where the positioning accuracy of aircraft coordinates is not pursued, but the positioning reliability must be guaranteed.

Efficient Hierarchical Signature Scheme with Batch Verification Function Suitable for ADS-B System

The federal aviation administration (FAA) has ruled that starting January 1, 2020, all aircraft flying over the United States must be equipped with an automatic dependent surveillance-broadcast (ADS-B) system to broadcast aircraft location information. The plaintext communication between the ADS-B system and the ground transmission tower is extremely vulnerable to interception and tampering by criminals. In addition, because of the increasing volume of airport air traffic, the airport tower is unable to quickly and efficiently verify large numbers of aircraft from all over the world. To address these issues, a three-level hierarchical signature scheme with batch verification function suitable for ADS-B system is proposed. Based on computational Diffie-Hellman (CDH) assumption, we prove that the proposed scheme is secure against existing unforgeability. Futhermore, we show the advantages of our scheme in computational cost through experiments.

Facing airborne attacks on ADS-B data with autoencoders

The automatic dependent surveillance-broadcast (ADS-B) represents a major change in flight tracking and it is one of the key components in building the next generation of air transportation systems. However, several concerns have been raised regarding its vulnerabilities to cyber attacks. In recent years, a new and promising approach of utilizing large-scale and publicly available flight recordings for training machine learning models that can detect anomalous flight patterns has been demonstrated as a valid countermeasure for several ADS-B attacks. The new approach differs significantly from previously proposed methods in the simplicity of its integration with the current ADS-B system. It also provides a valid countermeasure against highly sophisticated airborne attackers. However, previously proposed machine learning methods require training a different model for each flight route or geographic location to give acceptable results. This requirement limits the current solution to flights with a sufficient amount of historical data, which is unavailable in many cases such as business aviation, instructional flying, aerial work, and more. In this research, we address this limitation of previous work, by applying a differencing time-series transformation on the ADS-B data and utilizing a non-recurrent autoencoder classifier. The effectiveness of our method is compared to existing methods on several simulated trajectory modification attacks. The results of our experiments show that the proposed method achieves a ROC AUC value of 0.935-0.951, in comparison to 0.627 from existing methods when evaluated on flights that are absent from training data.

Enhancing Security of ADS-B Systems with Encryption Algorithm in the Smart Ocean

Liu, Z.; Ling, M.; Zhu, T.; Xu, D.; He, Y., and Liu, Z., 2020. Enhancing security of ADS-B systems with encryption algorithm in the smart ocean. In: Hu, C. and Cai, M. (eds.), Geo-informatics and Oceanography. Journal of Coastal Research, Special Issue No. 105, pp. 181–184. Coconut Creek (Florida), ISSN 0749-0208.The smart ocean is an influencer concept incorporating digitalized associated ocean and seaboard cities. The construction of an omni-bearing smart ocean requires urban resilience, and the application of smart means can greatly improve a city's emergency response capability in the face of dangerous events. Aviation security is a non-negligible point in the construction of the smart ocean. The automatic dependent surveillance-broadcast (ADS-B) in the aircrafts is used to broadcast and transmit navigating data, including the call sign of aircraft, altitude in the airspace, current heading of destination, and other locating messages. This paper studies ADS-B security threats such as distributed denial of service attacks and proposes the use of an encryption algorithm to process ADS-B plaintext to improve urban resilience of the smart ocean.

A digital model of airport surface traffic

The article proposes a digital model for determining permissible trajectories of objects moving within the air-port landside area. This model can be used for assessing the reliability of information provided by automatic dependent surveillance systems, as well as for filtering false targets. False targets can arise due to reflection of radio signals emitted by surveillance systems from large objects, as well as due to active interference or spoofing attacks. The developed model is of particular importance for assessing the reliability of information provided by automatic dependent surveillance-broadcast systems at aerodromes with an average level of traffic complexity, since it allows simpler solutions in terms of surveillance compared to multilateration systems or secondary surveillance radar systems operating in Mode S.

A new provable hierarchical anonymous certificateless authentication protocol with aggregate verification in ADS-B systems

Automatic Dependent Surveillance-Broadcast (ADS-B) technology is a new solution for communication among aircraft and ground controller stations. In this new surveillance technology, critical messages (e.g., the location of aircraft) are achieved by navigation satellites, and then an on-board equipment multicasts the unencrypted messages twice per second to the others. The former ADS-B protocols suffer from weak authentication protocols with a few security vulnerabilities and privacy issues including key-escrow problem, user profiling, time consuming verification processes, and difficulties with certificate management. In this paper, we propose a new hierarchical authentication protocol used Certificateless Public Key Cryptography (CL-PKC) technique to avoid using Public Key Infrastructure (PKI) certificate management and solve the key-escrow concern in Identity-based Public Key Cryptography (ID-PKC). Further, unlike many of certificateless schemes, our proposed scheme is secure against malicious-but-passive Key Generation Center (KGC). We prove that our scheme preserves conditional privacy, which means that distinct identities map to varied pseudonyms. The security and privacy features of our scheme are provably modeled under the widely-accepted random oracle model by computational Diffie-Hellman (CDH) assumption against adaptive chosen-message attack. Finally, we show that the time needed to aggregate verification of 50 messages reduced by 84% and 48% compared to those of Yang et al.’s and He et al.’s schemes respectively.

ADS-B spoofing attack detection method based on LSTM

The open and shared nature of the Automatic Dependent Surveillance Broadcast (ADS-B) protocol makes its messages extremely vulnerable to various security threats, such as jamming, modification, and injection. This paper proposes a long short-term memory (LSTM)-based ADS-B spoofing attack detection method from the perspective of data. First, the message sequence is preprocessed in the form of a sliding window, and then, an LSTM network is used to perform prediction training on the windows. Finally, the residual set of predicted values and true values is calculated to set a threshold. As a result, we can detect a spoofing attack and further identify which feature was attacked. Experiments show that this method can effectively detect 10 different kinds of simulated manipulated ADS-B messages without further increasing the complexity of airborne applications. Therefore, the method can respond well to the security threats suffered by the ADS-B system.

Backward Compatible Physical Layer Protocol Evolution for ADS-B Message Authentication

The automatic dependent surveillance-broadcast system is a pillar of the future air traffic control system. It is a surveillance system in which air planes transmit their information (identity, position, velocity, etc.) in broadcast to any listener equipped with a receiver. Networks of ADS-B receivers have been installed all over the world, producing a clear traffic awareness for air traffic controllers. For historical reasons, this protocol does not have any authentication/encryption mechanism. The aim of this article is to improve the ADS-B system security by introducing a physical layer protocol modification for the introduction of an authentication scheme. The proposed evolution fully complies with the current standard and exploits the phase modulation to increase the number of bits that can be transmitted with a single packet of data. These additional bits can be used to carry authentication information, making the overall system more secure (and safe). The proposed protocol evolution is developed ensuring backward compatibility and respecting the ICAO and RTCA recommendations; it can be introduced and used together with the present standard in a mixed scenario, allowing a smooth transition from the present protocol to the new one. Protocol performances were evaluated by simulations and, moreover, its feasibility and compliance with recommendations were tested using a software-defined radio (as transmitter) and a laboratory ADS-B receiver.

Integrated antenna and receiver system with self-calibrating digital beamforming for space-based ADS-B

This paper describes a digital beamforming (DBF) system with a self-calibrating function to receive Automatic Dependent Surveillance-Broadcast (ADS-B) signals on a satellite, which can expand the coverage range and improve the detection probability that is mainly reduced by multi-signal collision. This system integrates a 4 × 4 microstrip array antenna and a 16-channel receiver into a cuboid box that can simultaneously generate more than 19 independent beams whose size and direction can be flexibly controlled. Specifically, the on-orbit self-calibration method, signal processing algorithm, antenna and receiver design, and system test method are presented in this paper. Test results in a microwave anechoic chamber verified that the design can significantly improve the sensitivity of the receiver, reduce signal collision, and enhance the reliability of the space-based ADS-B system.

Security Issues in Automatic Dependent Surveillance - Broadcast (ADS-B): A Survey

As a new generation of air transportation surveillance technology, the automatic dependent surveillance - broadcast (ADS-B) system mainly completes the extraction and processing of the position information and other additional information of the aviation aircraft to form a clear and intuitive background map and trajectory. However, ADS-B broadcasts information via open and unencrypted protocols, it is vulnerable to deliberate intrusions and attacks, which poses a great security risk. This paper studies the security issues of the ADS-B system in information leakage and tampering. Starting from the vulnerability of the ADS-B system, it is divided into vulnerability based on attack intention and vulnerability based on security requirements. Various solutions for solving vulnerabilities from two aspects, secure location authentication, and secure broadcast authentication are proposed, and the solutions are compared in terms of security and feasibility. The research results show that a single solution does not fully protect the security of the ADS-B system. For example, the PKI (Public Key Infrastructure) technology and the SS (Spread Spectrum) technology can resist most attacks, but there are still deficiencies. Therefore, this paper proposes to propose a multi-layered security framework in future research work, which includes detecting and preventing different attacks in the ADS-B system.

Implementation of Automatic Aircraft Tracking with RTL-SDR

To improve the efficiency, safety, and capacity of air space system, an Automatic Dependent Surveillance-Broadcast (ADS-B) is one of the popular technologies used in air traffic surveillance. The ADS-B uses 1090 MHz band. ADS-B is complemented by existing radar-based technologies to locate aircraft. The coexistence of radar systems and ADS-B is a key system to detect and resolve conflicts in the Next Generation Air Transportation System (NGATS). But, the major disadvantage of ADS-B is its implementation complexity and increase in cost without user-friendly. This paper focuses to reduce the complexity and cost of ADS-B system implementation in MATLAB with the help of Software Defined Radio (SDR). SDR is user-friendly and easy to handle aircraft information without increasing the cost. The ADS-B system implemented with SDR can receive the multiple numbers of aircraft information such as altitude, latitude, longitude, speed, and direction in real-time. Usage of SDR maximizes the information coverage with reliability and can achieve timely communication in Air Traffic Control (ATC) networks.

On the Applicability of Satellite-Based Air Traffic Control Communication for Security

As air traffic control communication moves toward digital systems, there is an emerging trend toward supplementing or even fully substituting the traditional air-ground link in favor of communication between aircraft and satellites. In this article, we analyze coverage and security against wireless attacks of the novel satellite-based version of the Automatic Dependent Surveillance-Broadcast (ADS-B) technology. We compare it to the widely deployed terrestrial ADS-B system, which is known to be insecure and is inherently unable to provide coverage in some parts of the global airspace, such as oceans and polar regions. Our analysis shows that satellites can provide vast advantages in such non-surveillance areas. However, they are as fundamentally insecure as terrestrial ADS-B.

Metode Deteksi ‘Potential Security Threats’ Pada ADS-B Data dengan Memonitor EM Emisi Radiasi pada Jaringan Ethernet

Precision, Navigation, and Timing (PNT) system based on Global Navigation Satellite System (GNSS) becomes significant in the air traffic management, especially in the use of Automatic Dependent Surveillance Broadcast system (ADS-B) for air traffic monitoring. Therefore the integrity of GNSS is significant to provide a reliable data necessary for ADS-B. GNSS Interference due to intentional or unintentional surrounding signal source may decrease the integrity of GNSS signal and therefore may result in the in-accurate position data of ADS-B message. ADS-B message itself is also vulnerable from potential security threats in their network. This paper proposed a methodology to detect potential security threats of ADS-B network system for both GNSS signal and ADS-B data by measuring and monitoring the electromagnetic radiated emission from ethernet cable IPv4 Cat5.