Roberto Sabatini | Khalifa University (original) (raw)
Papers by Roberto Sabatini
AIAA/IEEE 42nd Digital Avionics Systems Conference (DASC 2023), 2023
Large constellations of Low Earth Orbit (LEO) satellites are expected to play a key role in a wid... more Large constellations of Low Earth Orbit (LEO) satellites are expected to play a key role in a wide spectrum of applications, ranging from communication and Internet of Things (IoT) to Earth Observation (EO) and navigation augmentation services. One important application area is that of cooperative and non-cooperative surveillance for Resident Space Object (RSO) tracking and Collision Avoidance (CA). Currently, various commercial entities have plans to deploy groups of compact to moderate-sized satellites, reaching a cumulative count of more than 20,000 satellites. This poses an unprecedented challenge to satellite operators, emphasizing the need for advanced sensing and tracking techniques that provides real-time information about RSO. In this context, the use of Distributed Satellite Systems (DSS) for Space-Based Space Surveillance (SBSS) has recently received much attention, thanks to their flexibility, responsiveness and adaptability to structural and functional changes. This paper proposes a novel method for non-cooperative surveillance of RSOs using connected and intelligent DSS (iDSS). This will assist in mitigating the risk of collisions, thereby contributing to enhanced Space Domain Awareness (SDA) and to safer, more sustainable near-Earth space operations. The integration of our proposed SBSS with ground-based SDA techniques is very promising, laying foundations for a future Space Traffic Management (STM) framework, whose primary task would be ensuring Separation Assurance (SA) and Collision Avoidance (CA), largely without a direct intervention of human groundstation operators. The validity of the proposed SBSS techniques is verified through simulation case studies performed in representative conditions.
AIAA/IEEE 42st Digital Avionics Systems Conference (DASC 2023) - AESS Public Tutorial, 2023
A surging interest in space launch operations and in Advanced Air Mobility (AAM) concepts is exac... more A surging interest in space launch operations and in Advanced Air Mobility (AAM) concepts is exacerbating the limitations of current practices, still heavily reliant on airspace segregation and not supporting the multimodal/intermodal evolution of air and space transport. For a successful integration of these new transport modes, it is critical that an acceptable level of safety is provided, requiring the development of novel digital tools (e.g., mission planning and decision support systems) that utilize advanced Cyber-Physical Systems (CPS) and Artificial Intelligence (AI) technologies to allow a seamless integration of space operations in the current ATM network. This tutorial addresses the role of Aerospace CPS (ACPS) and AI research to enable the safe, efficient and sustainable development of the air and space transport sector in the next decade. While the technical maturity of propulsive and vehicle technologies is relatively high, there are several opportunities and challenges associated with the adoption of CPS and AI to enable the integration of point-to-point suborbital spaceflight with conventional atmospheric air transport. Current research aims at developing robust and fault-tolerant CPS architectures that ensure trusted autonomous air/space transport operations with the given hardware constraints, despite the uncertainties in physical processes, the limited predictability of environmental conditions, the variability of mission requirements, and the possibility of both cyber and human errors. A key point in these advanced CPS is the control of physical processes from the monitoring of variables and the use of computational intelligence to obtain a deep knowledge of the monitored environment, thus providing timely and more accurate decisions and actions. The growing interconnection of physical and digital elements, and the introduction of highly sophisticated and efficient AI techniques, has led to a new generation of CPS, that is referred to as intelligent (or smart) CPS (iCPS). By equipping physical objects with interfaces to the virtual world, and incorporating intelligent mechanisms to leverage collaboration between these objects, the boundaries between the physical and virtual worlds become blurred. Interactions occurring in the physical world are capable of changing the processing behavior in the virtual world, in a causal relationship that can be exploited for the constant improvement of processes. Exploiting iCPS, intelligent, self-aware, self-managing and self-configuring systems can be built to improve the efficiency of air and space transport, and to build trusted autonomy. However, aviation safety certification is established upon verifying that all possible safety-critical conditions have been identified and verified. Whereas, in the case of AI real-time software evolution cannot be perfectly predicted and verified in advance, this is the real challenge to certification. One solution is to specify AI functional boundaries in correlation with real-time monitoring and validation of AI solution. Implementation can be sequential with practical ground-based AI for scheduling and routing being the starting point. Next in line will be simpler, non-flight critical functions and finally moving on to flight or safety critical systems. Building a certification case requires that the final product operates in all modes and performs consistently and successfully under all actual operational and environmental conditions founded on conformance to the applicable specifications. This is one of the greatest challenges currently faced by the avionics and Air Traffic Management (ATM) industry, which is clearly amplified in the context of future commercial space transport operations. Much attention is currently being devoted to the on-orbit phase, where the unique hazards of the space environment are being examined and the required iCPS evolutions for Resident Space Objects (RSO) de-confliction and collision avoidance are being addressed, including the synergies between existing ground-based tracking systems and rapidly evolving Space-Based Space Surveillance (SBSS) solutions. The advancement of regulatory frameworks supporting spacecraft operations is a conspicuous factor, which requires a holistic approach and extensive government support for the successful development and establishment of sustainable business models, including space debris mitigation strategies, operational risk assessment and liability issues. Within the atmospheric domain, extensions and alternatives to the conventional airspace segregation approaches must be identified including ATM and Air Traffic Flow Management (ATFM) techniques to facilitate the integration of new-entrant platforms. Lastly, adequate modelling approaches to meet on-orbit risk criteria must be developed and evolutionary requirements to improve current operational procedures (and associated regulatory frameworks) must be addressed in order to establish a fully-integrated Multi-Domain Traffic Management (MDTM) framework, including AI-driven situation awareness and decision support mechanisms for air and space traffic management.
AIAA/IEEE 42nd Digital Avionics Systems Conference (DASC 2023), 2023
Thanks to their rapid uptake in various industries, an increasing number of Uninhabited Aircraft ... more Thanks to their rapid uptake in various industries, an increasing number of Uninhabited Aircraft Systems (UAS) and other emerging aerospace platforms is expected to operate in the shared airspace. Viable conflict detection and resolution as well as demand-capacity balancing (DCB) services will be required to ensure the desired level of safety, particularly with the proliferation of Beyond Line-of-Sight (BLOS) operations. This paper proposes a novel UAS Traffic Management (UTM) system DCB functionality adopting multiple Artificial Intelligence (AI) algorithms to manage both regular and emergency situations. The system is based on a fourdimensional trajectory (4DT) planning algorithm with a flexible DCB process and solution framework. The method is not limited to fixed routing, but can also adjust dynamically to evolving conditions. The selected AI techniques are based on the most suitable machine learning and metaheuristic algorithms. Simulation case studies demonstrate that the proposed method allows to achieve a safe and efficient management of dense traffic in low-altitude airspace around cities and suburbs.
Wiley Aerospace Series - John Wiley and Sons, 2023
Sustainable Aviation Technology and Operations provides an updated and timely outlook of recent r... more Sustainable Aviation Technology and Operations provides an updated and timely outlook of recent research in aeronautics and air transport, with emphasis on current environmental objectives and achievements. The book discusses some of the most promising advances in sustainable aircraft and air traffic management technologies including: aircraft systems, aerodynamics, propulsion, structures, materials, biofuels, autonomous systems, air traffic flow management and dynamic airspace management. The physical processes associated with production and environmental impacts of various aircraft emissions, including air pollutants, noise and contrails, are presented to support the development of computational models for aircraft design, mission planning and trajectory optimisation. Relevant advances in systems engineering and lifecycle management processes are also covered, identifying the existing gaps in both academic research and industry best practices towards developing viable solutions. A set of research case studies concludes and complements the book, addressing aircraft design, systems design and mission optimisation for a more efficient and environmentally sustainable air transport.
43rd IEEE International Geoscience and Remote Sensing Symposium (IGARSS 2023), 2023
Volcanic eruptions are a natural hazard that can devastate people and property. In recent years, ... more Volcanic eruptions are a natural hazard that can devastate people and property. In recent years, the number of volcanic eruptions has been on the rise, and the effects of climate change are making them more frequent and more powerful. This research proposes a new methodology for monitoring volcanoes in realtime or very close to real-time using an intelligent Distributed Satellite System (iDSS). The iDSS is made up of a constellation of satellites that are all connected to one another by means of Inter-Satellite Links (ISL). This allows the data to be processed and distributed in real-time, which is essential for early warning of volcanic eruptions. In previous studies, the on-board volcanic eruption detection was proven to be possible and feasible by utilising appropriate Artificial Intelligence (AI) techniques. Multispectral optical data were used to assess if an active volcanic eruption was captured in the image. The proposed iDSS architecture is practical and can be used to monitor volcanoes in real-time or near real-time. The system has been tested by taking Mount Etna as a case study and the results have been reported. The findings and conclusions of this research can be applied to and expanded upon in the context of similar natural disasters occurring around the globe.
74th International Astronautical Congress (IAC), 2023
Distributed Satellite Systems (DSS) require new advanced navigation and control functionalities t... more Distributed Satellite Systems (DSS) require new advanced navigation and control functionalities to meet the ever more stringent mission requirements of Earth Observation (EO) missions. In particular, Autonomous Orbit Determination and Control (AODC) can significantly reduce operational costs and enable continuous feedback without being limited by ground station link availability. Recent advancements in Global Navigation Satellite System (GNSS) navigation in space, coupled with high-efficiency low-thrust electric propulsion, have made it possible to leverage autonomous and continuous operations to optimise propellant mass and thruster power, improve orbital accuracy, reduce collision risks, and develop new services through distributed operations. Within this framework, we propose a novel concept for a DSS that implements a Constellation of Formations (COF) architecture for EO missions, offering the advantage of combining single-pass multiple acquisitions with high revisit frequencies. However, maintaining the formation geometry and constellation parameters may conflict with each other. To address this challenge, we propose a control architecture that incorporates suitable loops for the (absolute) constellation orbit control and the (relative) formation orbit control using inter-satellite communication links within each formation.
IEEE AESS Distinguished Lecture, 2023
This Distinguished Lecture of the IEEE Aerospace and Electronic Systems Society (AESS) addresses ... more This Distinguished Lecture of the IEEE Aerospace and Electronic Systems Society (AESS) addresses the role of digital avionics and astrionics systems research in enabling the safe, efficient and sustainable development of the air and space transport sector. The aim is to disseminate recent technological/regulatory advances and to identify opportunities for industrial innovation in strategic areas, such as future Decision Support Systems (DSS) for Intent Based Operations (IBO) and Multi-Domain Traffic Management (MDTM). Starting from SESAR/NextGen top-level requirements, the DL focusses on integrated Communication, Navigation and Surveillance/ATM and Avionics (CNS+A) system architectures implementing 4-Dimensional Trajectory Optimisation (4DTO) algorithms, data link communications and enhanced surveillance technologies, as well as adaptive cognitive forms of Human-Machine Interface and Interaction (HMI2), allowing the automated negotiation and validation of aircraft intents for safer and more efficient ATM operations. As an integral part of this CNS+A evolutionary process, specific requirements for Unmanned Aircraft Systems (UAS) navigation, communication and cooperative/non-cooperative Sense-and-Avoid (SAA) are being addressed in order to allow the safe and unrestricted access of UAS to all classes of airspace. In parallel with air transport developments, progress in spaceflight research has led to the introduction of various manned and unmanned reusable space vehicle concepts, opening up uncharted opportunities for the newborn space transport industry. For future space transport operations to be technically and commercially viable, it is critical that an acceptable level of safety is provided, requiring the development of novel digital tools (e.g., mission planning and decision support systems) that utilize advanced CNS+A technologies, and allowing a seamless integration of space operations in the current ATM network. While the technical maturity of propulsive and vehicle technologies is relatively high, a recent review of emerging platform operational concepts highlights the challenges (and opportunities) brought in by the adoption of cyber-physical and autonomous systems for integration of point-to-point suborbital spaceflight with conventional atmospheric air transport. In particular, various viable launch and re-entry methodologies were addressed, where the physical and computational limitations of these approaches was identified and applicability to future commercial space transport operations was assessed. Recent research is turning greater attention to the on-orbit phase, where the unique hazards of the space environment are being examined and the necessary elements required for space object de-confliction and collision avoidance modelling are analysed. The evolution of regulatory frameworks supporting spacecraft operations is a conspicuous factor, which requires a holistic approach and extensive government support for the successful development and establishment of sustainable business models, including space debris mitigation strategies, operational risk assessment and liability issues. Within the atmospheric domain, extensions and alternatives to the conventional airspace segregation approaches must be identified including ATM/ATFM techniques to facilitate the integration of new-entrant platforms. Lastly, adequate modelling approaches to meet on-orbit risk criteria must be developed and evolutionary requirements to improve current operational procedures (and associated regulatory frameworks) must be addressed in order to establish a fully-integrated Multi-Domain Traffic Management (MDTM) framework.
IEEE Aerospace and Electronic Systems Magazine, 2023
The integration of unmanned aircraft systems (UAS) in all classes of airspace represents, at the ... more The integration of unmanned aircraft systems (UAS) in all classes of airspace represents, at the same time, an evolutionary and a revolutionary step in air transport operations. As a result, new concepts have emerged for UAS traffic management to support the anticipated traffic density growth and the need for safe beyond visual line-of-sight operations. Closely linked with these developments, urban/advanced air mobility (UAM/AAM) has appeared as a new and disruptive dimension for aviation, potentially enabling mobility of goods and people at a different scale compared with current operations, while also emphasizing the need of seamless integration with the existing air traffic management (ATM) framework. These UAS capabilities are reshaping the future of aviation, but also challenge traditional paradigms, requiring significant advances both in technologies and regulations, while keeping strong links with public communities and the perception of societal benefits. As an example, a key role is played by the progress of communications, navigation and surveillance technologies, such as sense-and-avoid and global navigation satellite systems-resilient, alternate position, navigation, and timing systems, and by the seamless integration of airborne and ground infrastructure within a cyber-aware context. Similarly, significant restructuring of the existing regulatory framework is needed to ensure that the integrity and safety of the AAM/ATM integrated airspace is maintained while enabling autonomous operations with higher technological flexibility and refresh rates. In view of these challenges, the AESS Avionics Systems Panel has compiled a special issue of the AESS Magazine whose focus is set on the most recent research and innovation developments in the field of UAM/AAM and UAS airspace integration. This special issue has been kept broad in scope with the aim of providing a wide overview of the state-of-the-art and development trends in the field, while also addressing the main research gaps that are currently being tackled actively by industry, government and academia.
Remote Sensing, 2023
Autonomous navigation (AN) and manoeuvring are increasingly important in distributed satellite sy... more Autonomous navigation (AN) and manoeuvring are increasingly important in distributed satellite systems (DSS) in order to avoid potential collisions with space debris and other resident space objects (RSO). In order to accomplish collision avoidance manoeuvres, tracking and characterization of RSO is crucial. At present, RSO are tracked and catalogued using ground-based observations, but space-based space surveillance (SBSS) represents a valid alternative (or complementary asset) due to its ability to offer enhanced performances in terms of sensor resolution, tracking accuracy, and weather independence. This paper proposes a particle swarm optimization (PSO) algorithm for DSS AN and manoeuvring, specifically addressing RSO tracking and collision avoidance requirements as an integral part of the overall system design. More specifically, a DSS architecture employing hyperspectral sensors for Earth observation is considered, and passive electro-optical sensors are used, in conjunction with suitable mathematical algorithms, to accomplish autonomous RSO tracking and classification. Simulation case studies are performed to investigate the tracking and system collision avoidance capabilities in both space-based and ground-based tracking scenarios. Results corroborate the effectiveness of the proposed AN technique and highlight its potential to supplement either conventional (ground-based) or SBSS tracking methods.
Sensors, 2023
Recent developments in Distributed Satellite Systems (DSS) have undoubtedly increased mission val... more Recent developments in Distributed Satellite Systems (DSS) have undoubtedly increased mission value due to the ability to reconfigure the spacecraft cluster/formation and incrementally add new or update older satellites in the formation. These features provide inherent benefits, such as increased mission effectiveness, multi-mission capabilities, design flexibility, and so on. Trusted Autonomous Satellite Operation (TASO) are possible owing to the predictive and reactive integrity features offered by Artificial Intelligence (AI), including both on-board satellites and in the ground control segments. To effectively monitor and manage time-critical events such as disaster relief missions, the DSS must be able to reconfigure autonomously. To achieve TASO, the DSS should have reconfiguration capability within the architecture and spacecraft should communicate with each other through an Inter-Satellite Link (ISL). Recent advances in AI, sensing, and computing technologies have resulted in the development of new promising concepts for the safe and efficient operation of the DSS. The combination of these technologies enables trusted autonomy in intelligent DSS (iDSS) operations, allowing for a more responsive and resilient approach to Space Mission Management (SMM) in terms of data collection and processing, especially when using state-of-the-art optical sensors. This research looks into the potential applications of iDSS by proposing a constellation of satellites in Low Earth Orbit (LEO) for near-real-time wildfire management. For spacecraft to continuously monitor Areas of Interest (AOI) in a dynamically changing environment, satellite missions must have extensive coverage, revisit intervals, and reconfiguration capability that iDSS can offer. Our recent work demonstrated the feasibility of AI-based data processing using state-of-the-art on-board astrionics hardware accelerators. Based on these initial results, AI-based software has been successively developed for wildfire detection on-board iDSS satellites. To demonstrate the applicability of the proposed iDSS architecture, simulation case studies are performed considering different geographic locations.
44th IEEE Aerospace Conference (AeroConf 2023), 2023
Space debris population has increased dramatically in the past decades posing a threat to the fut... more Space debris population has increased dramatically in the past decades posing a threat to the future of space operations. Traditionally, Resident Space Objects (RSO) are tracked and catalogued using ground-based observations. However, Space Based Space Surveillance (SBSS) is a promising technology to complement the ground-based observations as it offers greater performance in terms of detectability, accuracy and weather independency. A Distributed Satellite System (DSS) architecture is proposed for a SBSS mission equipped with dual-use star trackers and inter-satellite communication links to interact and cooperate with each other to accomplish optimized RSO tracking tasks while assumed to simultaneously perform earth observation tasks.This paper focuses on stereovision-based tracking algorithms with higher detectability and tracking accuracy in SBSS tasks in order to identify an optimal tracking solution for Space Domain Awareness (SDA), which could support future Space Traffic Management (STM) operations. Navigation and tracking uncertainties are analyzed in representative conditions to support the optimal selection and processing of individual observations and to determine the actual confidence region around the detected objects. Additionally, Particle Swarm Optimization (PSO) is implemented on-board the satellites to grant the DSS autonomous trajectory planning and Collision Avoidance (CA) manoeuvring capabilities.
44th IEEE Aerospace Conference (AeroConf 2023), 2023
One of the key challenges that the Advanced Air Mobility (AAM) sector faces is airspace segregati... more One of the key challenges that the Advanced Air Mobility (AAM) sector faces is airspace segregation, which represents a conservative approach to minimize the risk of midair collisions between unmanned and manned aircraft. UAS must have the capabilities to identify, detect and resolve any possible conflicts or collision threats. Sense-and-avoid (SAA) algorithms are responsible for separation assurance and collision avoidance. SAA systems are becoming a requirement for UAS operations. In this paper, we extend the concept of collision avoidance to not only include avoiding a possible impact but also evading possible encounters of wake turbulence from intruder aircraft. This novel approach can greatly increase the capability of SAA by minimizing not only the risk of collision but also the loss of control due to any wake vortices. Moreover, a model for calculating the safe separation distance between different combinations of aircraft based on wake vortices intensity and decay is presented. Real-life effects such as wind turbulence are analyzed to study the effect on the effectiveness of the SAA system. In this paper, we focus on generating avoidance volumes that encapsulate both the hazardous wake and the uncertainty arising from the stochastic nature of wind turbulence. This is simulated as an encounter between two Manned/Unmanned Aerial Vehicles, which resembles a typical interaction scenario in the AAM field.
Australian International Aerospace Congress (AIAC20), 2023
A robust multi-baseline along-track interferometric Synthetic Aperture Radar (SAR) formation flyi... more A robust multi-baseline along-track interferometric Synthetic Aperture Radar (SAR) formation flying concept is proposed to combine effectively several along-track baseline observations for real-time single-pass acquisition purposes. Simulation results are given to support the feasibility of implementing this acquisition mode with autonomous orbit control, using low thrust actuation suitable for electric propulsion. To improve repeatability, a constellation of this formation concept may combine the benefits of these two distributed satellite systems. A maritime domain awareness application is considered as a hypothetical mission to be solved by this combined approach.
Designs, 2023
The accurate modelling and simulation of vehicle dynamics is a fundamental prerequisite for the d... more The accurate modelling and simulation of vehicle dynamics is a fundamental prerequisite for the design and experimental flight testing of aerospace vehicles. In the case of high-altitude supersonic sounding rockets, it is critically important to produce realistic trajectory predictions in a representative range of operational and environmental conditions as well as to produce reliable probability distributions of terminal locations. This article proposes a methodology to develop high-fidelity flight dynamics models that accurately capture aeroelastic, turbulence, atmospheric and other effects relevant to sounding rockets. The significance of establishing a high-fidelity model and of addressing such a problem in the context of developing a digital twin are discussed upfront, together with the key tools utilised in the analysis. In addition to state-of-the-art computational methods to determine the aerodynamic forces, moments and mass changes in various flight regimes (including parachute release), a detailed methodology for incorporating the dynamic aeroelastic response of the rocket is presented. The validity of the proposed method is demonstrated through a simulation case study, which utilises data from an existing rocket prototype. Results corroborate the correct implementation of the proposed algorithms and provide foundations for future research on virtual sensing and digital twin for autonomous navigation and guidance.
Aerospace, 2023
Space-based Earth Observation (EO) systems have undergone a continuous evolution in the twenty-fi... more Space-based Earth Observation (EO) systems have undergone a continuous evolution in the twenty-first century. With the help of space-based Maritime Domain Awareness (MDA), specially Automatic Identification Systems (AIS), their applicability across the world's waterways, among others, has grown substantially. This research work explores the potential applicability of Synthetic Aperture Radar (SAR) and Distributed Satellite System (DSS) for the MDA operation. A robust multi-baseline Along-Track Interferometric Synthetic Aperture Radar (AT-InSAR) formation flying concept is proposed to combine several along-track baseline observations effectively for single-pass interferometry. Simulation results are presented to support the feasibility of implementing this acquisition mode with autonomous orbit control, using low-thrust actuation suitable for electric propulsion. To improve repeatability, a constellation of this formation concept is also proposed to combine the benefits of the DSS. An MDA application is considered as a hypothetical mission to be solved by this combined approach.
Remote Sensing, 2023
One of the United Nations (UN) Sustainable Development Goals is climate action (SDG-13), and wild... more One of the United Nations (UN) Sustainable Development Goals is climate action (SDG-13), and wildfire is among the catastrophic events that both impact climate change and are aggravated by it. In Australia and other countries, large-scale wildfires have dramatically grown in frequency and size in recent years. These fires threaten the world’s forests and urban woods, cause enormous environmental and property damage, and quite often result in fatalities. As a result of their increasing frequency, there is an ongoing debate over how to handle catastrophic wildfires and mitigate their social, economic, and environmental repercussions. Effective prevention, early warning, and response strategies must be well-planned and carefully coordinated to minimise harmful consequences to people and the environment. Rapid advancements in remote sensing technologies such as ground-based, aerial surveillance vehicle-based, and satellite-based systems have been used for efficient wildfire surveillance. This study focuses on the application of space-borne technology for very accurate fire detection under challenging conditions. Due to the significant advances in artificial intelligence (AI) techniques in recent years, numerous studies have previously been conducted to examine how AI might be applied in various situations. As a result of its special physical and operational requirements, spaceflight has emerged as one of the most challenging application fields. This work contains a feasibility study as well as a model and scenario prototype for a satellite AI system. With the intention of swiftly generating alerts and enabling immediate actions, the detection of wildfires has been studied with reference to the Australian events that occurred in December 2019. Convolutional neural networks (CNNs) were developed, trained, and used from the ground up to detect wildfires while also adjusting their complexity to meet onboard implementation requirements for trusted autonomous satellite operations (TASO). The capability of a 1-dimensional convolution neural network (1-DCNN) to classify wildfires is demonstrated in this research and the results are assessed against those reported in the literature. In order to enable autonomous onboard data processing, various hardware accelerators were considered and evaluated for onboard implementation. The trained model was then implemented in the following: Intel Movidius NCS-2 and Nvidia Jetson Nano and Nvidia Jetson TX2. Using the selected onboard hardware, the developed model was then put into practice and analysis was carried out. The results were positive and in favour of using the technology that has been proposed for onboard data processing to enable TASO on future missions. The findings indicate that data processing onboard can be very beneficial in disaster management and climate change mitigation by facilitating the generation of timely alerts for users and by enabling rapid and appropriate responses.
IEEE Geoscience and Remote Sensing Letters, 2022
Climate action (SDG-13) is an integral part of the Sustainable Development Goals (SDGs) set by th... more Climate action (SDG-13) is an integral part of the Sustainable Development Goals (SDGs) set by the United Nations (UN), and wildfire is one of the catastrophic events related to climate change. Large-scale forest fires have drastically increased in frequency and size in recent years in Australia and other nations. These wildfires endanger the forests and urban areas of the world, demolish vast amounts of property, and frequently result in fatalities. There is a requirement for real-time/near realtime catastrophic event monitoring of fires due to their growing frequency. In order to effectively monitor disaster events, it will be feasible to manage them in real-time or near real-time, thanks to the advent of the Distributed Satellite System (DSS). This research examines the possible applicability of DSS for wildfire surveillance. For spacecraft to continually monitor the dynamically changing environment, satellite missions must have broad coverage and revisit intervals that DSS can fulfil. A feasibility analysis, as well as a model and scenario prototype for a satellite Artificial Intelligence (AI) system, are included in this paper to enable prompt action and swiftly provide alerts. In our previous research, it is shown that on-board implementation, i.e., data processing utilising hardware accelerators, is feasible. To enable Trusted Autonomous Satellite Operation (TASO), the same will be included in the proposed DSS architecture, and the outcomes will be provided. To demonstrate the applicability, the suggested DSS architecture will be tested in several geographic locations to demonstrate the system-wide coverage.
FAA/NextGen TechTalk Speaker Series, 2022
This presentation addresses the role of digital avionics, astrionics and Air Traffic Management (... more This presentation addresses the role of digital avionics, astrionics and Air Traffic Management (ATM) systems research in enabling the safe, efficient and sustainable development of the air and space transport sector. The aim is to disseminate recent technological/regulatory advances and to identify opportunities for industrial innovation in strategic areas, such as future Decision Support Systems (DSS) for Intent Based Operations (IBO) and Multi-Domain Traffic Management (MDTM). Starting from SESAR/NextGen top-level requirements, the presentation focusses on integrated Communication, Navigation and Surveillance/ATM and Avionics (CNS+A) system architectures implementing 4-Dimensional Trajectory Optimisation (4DTO) algorithms, data link communications and enhanced surveillance technologies, as well as adaptive cognitive forms of Human-Machine Interface and Interaction (HMI2), allowing the automated negotiation and validation of aircraft intents for safer and more efficient ATM operations. As an integral part of this CNS+A evolutionary process, specific requirements for Unmanned Aircraft Systems (UAS) navigation, communication and cooperative/non-cooperative Sense-and-Avoid (SAA) are being addressed in order to allow the safe and unrestricted access of UAS to all classes of airspace. In parallel with air transport developments, progress in spaceflight research has led to the introduction of various manned and unmanned reusable space vehicle concepts, opening up uncharted opportunities for the newborn space transport industry. For future space transport operations to be technically and commercially viable, it is critical that an acceptable level of safety is provided, requiring the development of novel digital tools (e.g., mission planning and decision support systems) that utilize advanced CNS+A technologies, and allowing a seamless integration of space operations in the current ATM network. While the technical maturity of propulsive and vehicle technologies is relatively high, a recent review of emerging platform operational concepts highlights the challenges (and opportunities) brought in by the adoption of cyber-physical and autonomous systems for integration of point-to-point suborbital spaceflight with conventional atmospheric air transport. In particular, various viable launch and re-entry methodologies were addressed, where the physical and computational limitations of these approaches was identified and applicability to future commercial space transport operations was assessed. Recent research is turning greater attention to the on-orbit phase, where the unique hazards of the space environment are being examined and the necessary elements required for space object de-confliction and collision avoidance modelling are analysed. The evolution of regulatory frameworks supporting spacecraft operations is a conspicuous factor, which requires a holistic approach and extensive government support for the successful development and establishment of sustainable business models, including space debris mitigation strategies, operational risk assessment and liability issues. Within the atmospheric domain, extensions and alternatives to the conventional airspace segregation approaches must be identified including ATM/ATFM techniques to facilitate the integration of new-entrant platforms. Lastly, adequate modelling approaches to meet on-orbit risk criteria must be developed and evolutionary requirements to improve current operational procedures (and associated regulatory frameworks) must be addressed in order to establish a fully-integrated Multi-Domain Traffic Management (MDTM) framework.
IEEE International Conference on Metrology for Extended Reality, Artificial Intelligence and Neural Engineering (MetroXRAINE), 2022
This paper investigates the opportunity to use artificial intelligence methodologies and edge com... more This paper investigates the opportunity to use artificial intelligence methodologies and edge computing approaches for wildfire detection directly from satellite platforms. The test case for our study is PRISMA (Precursore IperSpettrale della Missione Applicativa-Hyperspectral Precursor of the Application Mission), the Italian hyperspectral satellite launched in 2019 by the Italian Space Agency. This mission provides hyperspectral (HS) images in the spectral range of [0.4,2.5] μm and an average spectral resolution less than 10 nm. This work reports new results related to the Australian bushfires happened in December 2019 in New South Wales, captured by PRISMA on December 27, 2019. Starting from a one-dimensional convolutional neural network (CNN) discussed in previous authors’ works to perform multiclass classification, this paper primarily deals with the opportunity to use hardware accelerators, namely the Intel Movidius Myriad 2, the Nvidia Jetson TX2, and the Nvidia Jetson Nano, to consider the on-the-edge implementation of the CNN. This study is in line with the current impulse to improve on-board computing capabilities and platform autonomy, setting some of the elements for future satellites or constellations focusing on specific remote sensing tasks to provide real-time reliable early warnings.
IEEE/AIAA 41st Digital Avionics Systems Conference (DASC)
Satellite technologies are used for both civil and military purposes in the modern world, and typ... more Satellite technologies are used for both civil and military purposes in the modern world, and typical applications include Communication, Navigation and Surveillance (CNS) services, which have a direct impact several economic, social and environmental protection activity. The increasing reliance on satellite services for safety-of-life and mission-critical applications (e.g., transport, defense and public safety services) creates a severe, although often overlooked, security problem, particularly when it comes to cyber threats. Like other increasingly digitized services, satellites and space platforms are vulnerable to cyberattacks. Thus, the existence of cybersecurity flaws may pose major threats to space-based assets and associated key infrastructure on the ground. These dangers could obstruct global economic progress and, by implication, international security if they are not properly addressed. Mega-constellations make protecting space infrastructure from cyberattacks much more difficult. This emphasizes the importance of defensive cyber countermeasures to minimize interruptions and ensure efficient and reliable contributions to critical infrastructure operations. Very importantly, space systems are inherently complex Cyber-Physical System (CPS) architectures, where communication, control and computing processes are tightly interleaved, and associated hardware/software components are seamlessly integrated. This represents a new challenge as many known physical threats (e.g., conventional electronic warfare measures) can now manifest their effects in cyberspace and, vice-versa, some cyber-threats can have detrimental effects in the physical domain. The concept of cyberspace underlies nearly every aspect of modern society's critical activities and relies heavily on critical infrastructure for economic advancement, public safety and national security. Many governments have expressed the desire to make a substantial contribution to secure cyberspace and are focusing on different aspects of the evolving industrial ecosystem, largely under the impulse of digital transformation and sustainable development goals. The level of cybersecurity attained in this framework is the sum of all national and international activities implemented to protect all actions in the cyber-physical ecosystem. This paper focuses on cybersecurity threats and vulnerabilities in various segments of space CPS architectures. More specifically, the paper identifies the applicable cyber threat mechanisms, conceivable threat actors and the associated space business implications. It also presents metrics and strategies for countering cyber threats and facilitating space mission assurance.
AIAA/IEEE 42nd Digital Avionics Systems Conference (DASC 2023), 2023
Large constellations of Low Earth Orbit (LEO) satellites are expected to play a key role in a wid... more Large constellations of Low Earth Orbit (LEO) satellites are expected to play a key role in a wide spectrum of applications, ranging from communication and Internet of Things (IoT) to Earth Observation (EO) and navigation augmentation services. One important application area is that of cooperative and non-cooperative surveillance for Resident Space Object (RSO) tracking and Collision Avoidance (CA). Currently, various commercial entities have plans to deploy groups of compact to moderate-sized satellites, reaching a cumulative count of more than 20,000 satellites. This poses an unprecedented challenge to satellite operators, emphasizing the need for advanced sensing and tracking techniques that provides real-time information about RSO. In this context, the use of Distributed Satellite Systems (DSS) for Space-Based Space Surveillance (SBSS) has recently received much attention, thanks to their flexibility, responsiveness and adaptability to structural and functional changes. This paper proposes a novel method for non-cooperative surveillance of RSOs using connected and intelligent DSS (iDSS). This will assist in mitigating the risk of collisions, thereby contributing to enhanced Space Domain Awareness (SDA) and to safer, more sustainable near-Earth space operations. The integration of our proposed SBSS with ground-based SDA techniques is very promising, laying foundations for a future Space Traffic Management (STM) framework, whose primary task would be ensuring Separation Assurance (SA) and Collision Avoidance (CA), largely without a direct intervention of human groundstation operators. The validity of the proposed SBSS techniques is verified through simulation case studies performed in representative conditions.
AIAA/IEEE 42st Digital Avionics Systems Conference (DASC 2023) - AESS Public Tutorial, 2023
A surging interest in space launch operations and in Advanced Air Mobility (AAM) concepts is exac... more A surging interest in space launch operations and in Advanced Air Mobility (AAM) concepts is exacerbating the limitations of current practices, still heavily reliant on airspace segregation and not supporting the multimodal/intermodal evolution of air and space transport. For a successful integration of these new transport modes, it is critical that an acceptable level of safety is provided, requiring the development of novel digital tools (e.g., mission planning and decision support systems) that utilize advanced Cyber-Physical Systems (CPS) and Artificial Intelligence (AI) technologies to allow a seamless integration of space operations in the current ATM network. This tutorial addresses the role of Aerospace CPS (ACPS) and AI research to enable the safe, efficient and sustainable development of the air and space transport sector in the next decade. While the technical maturity of propulsive and vehicle technologies is relatively high, there are several opportunities and challenges associated with the adoption of CPS and AI to enable the integration of point-to-point suborbital spaceflight with conventional atmospheric air transport. Current research aims at developing robust and fault-tolerant CPS architectures that ensure trusted autonomous air/space transport operations with the given hardware constraints, despite the uncertainties in physical processes, the limited predictability of environmental conditions, the variability of mission requirements, and the possibility of both cyber and human errors. A key point in these advanced CPS is the control of physical processes from the monitoring of variables and the use of computational intelligence to obtain a deep knowledge of the monitored environment, thus providing timely and more accurate decisions and actions. The growing interconnection of physical and digital elements, and the introduction of highly sophisticated and efficient AI techniques, has led to a new generation of CPS, that is referred to as intelligent (or smart) CPS (iCPS). By equipping physical objects with interfaces to the virtual world, and incorporating intelligent mechanisms to leverage collaboration between these objects, the boundaries between the physical and virtual worlds become blurred. Interactions occurring in the physical world are capable of changing the processing behavior in the virtual world, in a causal relationship that can be exploited for the constant improvement of processes. Exploiting iCPS, intelligent, self-aware, self-managing and self-configuring systems can be built to improve the efficiency of air and space transport, and to build trusted autonomy. However, aviation safety certification is established upon verifying that all possible safety-critical conditions have been identified and verified. Whereas, in the case of AI real-time software evolution cannot be perfectly predicted and verified in advance, this is the real challenge to certification. One solution is to specify AI functional boundaries in correlation with real-time monitoring and validation of AI solution. Implementation can be sequential with practical ground-based AI for scheduling and routing being the starting point. Next in line will be simpler, non-flight critical functions and finally moving on to flight or safety critical systems. Building a certification case requires that the final product operates in all modes and performs consistently and successfully under all actual operational and environmental conditions founded on conformance to the applicable specifications. This is one of the greatest challenges currently faced by the avionics and Air Traffic Management (ATM) industry, which is clearly amplified in the context of future commercial space transport operations. Much attention is currently being devoted to the on-orbit phase, where the unique hazards of the space environment are being examined and the required iCPS evolutions for Resident Space Objects (RSO) de-confliction and collision avoidance are being addressed, including the synergies between existing ground-based tracking systems and rapidly evolving Space-Based Space Surveillance (SBSS) solutions. The advancement of regulatory frameworks supporting spacecraft operations is a conspicuous factor, which requires a holistic approach and extensive government support for the successful development and establishment of sustainable business models, including space debris mitigation strategies, operational risk assessment and liability issues. Within the atmospheric domain, extensions and alternatives to the conventional airspace segregation approaches must be identified including ATM and Air Traffic Flow Management (ATFM) techniques to facilitate the integration of new-entrant platforms. Lastly, adequate modelling approaches to meet on-orbit risk criteria must be developed and evolutionary requirements to improve current operational procedures (and associated regulatory frameworks) must be addressed in order to establish a fully-integrated Multi-Domain Traffic Management (MDTM) framework, including AI-driven situation awareness and decision support mechanisms for air and space traffic management.
AIAA/IEEE 42nd Digital Avionics Systems Conference (DASC 2023), 2023
Thanks to their rapid uptake in various industries, an increasing number of Uninhabited Aircraft ... more Thanks to their rapid uptake in various industries, an increasing number of Uninhabited Aircraft Systems (UAS) and other emerging aerospace platforms is expected to operate in the shared airspace. Viable conflict detection and resolution as well as demand-capacity balancing (DCB) services will be required to ensure the desired level of safety, particularly with the proliferation of Beyond Line-of-Sight (BLOS) operations. This paper proposes a novel UAS Traffic Management (UTM) system DCB functionality adopting multiple Artificial Intelligence (AI) algorithms to manage both regular and emergency situations. The system is based on a fourdimensional trajectory (4DT) planning algorithm with a flexible DCB process and solution framework. The method is not limited to fixed routing, but can also adjust dynamically to evolving conditions. The selected AI techniques are based on the most suitable machine learning and metaheuristic algorithms. Simulation case studies demonstrate that the proposed method allows to achieve a safe and efficient management of dense traffic in low-altitude airspace around cities and suburbs.
Wiley Aerospace Series - John Wiley and Sons, 2023
Sustainable Aviation Technology and Operations provides an updated and timely outlook of recent r... more Sustainable Aviation Technology and Operations provides an updated and timely outlook of recent research in aeronautics and air transport, with emphasis on current environmental objectives and achievements. The book discusses some of the most promising advances in sustainable aircraft and air traffic management technologies including: aircraft systems, aerodynamics, propulsion, structures, materials, biofuels, autonomous systems, air traffic flow management and dynamic airspace management. The physical processes associated with production and environmental impacts of various aircraft emissions, including air pollutants, noise and contrails, are presented to support the development of computational models for aircraft design, mission planning and trajectory optimisation. Relevant advances in systems engineering and lifecycle management processes are also covered, identifying the existing gaps in both academic research and industry best practices towards developing viable solutions. A set of research case studies concludes and complements the book, addressing aircraft design, systems design and mission optimisation for a more efficient and environmentally sustainable air transport.
43rd IEEE International Geoscience and Remote Sensing Symposium (IGARSS 2023), 2023
Volcanic eruptions are a natural hazard that can devastate people and property. In recent years, ... more Volcanic eruptions are a natural hazard that can devastate people and property. In recent years, the number of volcanic eruptions has been on the rise, and the effects of climate change are making them more frequent and more powerful. This research proposes a new methodology for monitoring volcanoes in realtime or very close to real-time using an intelligent Distributed Satellite System (iDSS). The iDSS is made up of a constellation of satellites that are all connected to one another by means of Inter-Satellite Links (ISL). This allows the data to be processed and distributed in real-time, which is essential for early warning of volcanic eruptions. In previous studies, the on-board volcanic eruption detection was proven to be possible and feasible by utilising appropriate Artificial Intelligence (AI) techniques. Multispectral optical data were used to assess if an active volcanic eruption was captured in the image. The proposed iDSS architecture is practical and can be used to monitor volcanoes in real-time or near real-time. The system has been tested by taking Mount Etna as a case study and the results have been reported. The findings and conclusions of this research can be applied to and expanded upon in the context of similar natural disasters occurring around the globe.
74th International Astronautical Congress (IAC), 2023
Distributed Satellite Systems (DSS) require new advanced navigation and control functionalities t... more Distributed Satellite Systems (DSS) require new advanced navigation and control functionalities to meet the ever more stringent mission requirements of Earth Observation (EO) missions. In particular, Autonomous Orbit Determination and Control (AODC) can significantly reduce operational costs and enable continuous feedback without being limited by ground station link availability. Recent advancements in Global Navigation Satellite System (GNSS) navigation in space, coupled with high-efficiency low-thrust electric propulsion, have made it possible to leverage autonomous and continuous operations to optimise propellant mass and thruster power, improve orbital accuracy, reduce collision risks, and develop new services through distributed operations. Within this framework, we propose a novel concept for a DSS that implements a Constellation of Formations (COF) architecture for EO missions, offering the advantage of combining single-pass multiple acquisitions with high revisit frequencies. However, maintaining the formation geometry and constellation parameters may conflict with each other. To address this challenge, we propose a control architecture that incorporates suitable loops for the (absolute) constellation orbit control and the (relative) formation orbit control using inter-satellite communication links within each formation.
IEEE AESS Distinguished Lecture, 2023
This Distinguished Lecture of the IEEE Aerospace and Electronic Systems Society (AESS) addresses ... more This Distinguished Lecture of the IEEE Aerospace and Electronic Systems Society (AESS) addresses the role of digital avionics and astrionics systems research in enabling the safe, efficient and sustainable development of the air and space transport sector. The aim is to disseminate recent technological/regulatory advances and to identify opportunities for industrial innovation in strategic areas, such as future Decision Support Systems (DSS) for Intent Based Operations (IBO) and Multi-Domain Traffic Management (MDTM). Starting from SESAR/NextGen top-level requirements, the DL focusses on integrated Communication, Navigation and Surveillance/ATM and Avionics (CNS+A) system architectures implementing 4-Dimensional Trajectory Optimisation (4DTO) algorithms, data link communications and enhanced surveillance technologies, as well as adaptive cognitive forms of Human-Machine Interface and Interaction (HMI2), allowing the automated negotiation and validation of aircraft intents for safer and more efficient ATM operations. As an integral part of this CNS+A evolutionary process, specific requirements for Unmanned Aircraft Systems (UAS) navigation, communication and cooperative/non-cooperative Sense-and-Avoid (SAA) are being addressed in order to allow the safe and unrestricted access of UAS to all classes of airspace. In parallel with air transport developments, progress in spaceflight research has led to the introduction of various manned and unmanned reusable space vehicle concepts, opening up uncharted opportunities for the newborn space transport industry. For future space transport operations to be technically and commercially viable, it is critical that an acceptable level of safety is provided, requiring the development of novel digital tools (e.g., mission planning and decision support systems) that utilize advanced CNS+A technologies, and allowing a seamless integration of space operations in the current ATM network. While the technical maturity of propulsive and vehicle technologies is relatively high, a recent review of emerging platform operational concepts highlights the challenges (and opportunities) brought in by the adoption of cyber-physical and autonomous systems for integration of point-to-point suborbital spaceflight with conventional atmospheric air transport. In particular, various viable launch and re-entry methodologies were addressed, where the physical and computational limitations of these approaches was identified and applicability to future commercial space transport operations was assessed. Recent research is turning greater attention to the on-orbit phase, where the unique hazards of the space environment are being examined and the necessary elements required for space object de-confliction and collision avoidance modelling are analysed. The evolution of regulatory frameworks supporting spacecraft operations is a conspicuous factor, which requires a holistic approach and extensive government support for the successful development and establishment of sustainable business models, including space debris mitigation strategies, operational risk assessment and liability issues. Within the atmospheric domain, extensions and alternatives to the conventional airspace segregation approaches must be identified including ATM/ATFM techniques to facilitate the integration of new-entrant platforms. Lastly, adequate modelling approaches to meet on-orbit risk criteria must be developed and evolutionary requirements to improve current operational procedures (and associated regulatory frameworks) must be addressed in order to establish a fully-integrated Multi-Domain Traffic Management (MDTM) framework.
IEEE Aerospace and Electronic Systems Magazine, 2023
The integration of unmanned aircraft systems (UAS) in all classes of airspace represents, at the ... more The integration of unmanned aircraft systems (UAS) in all classes of airspace represents, at the same time, an evolutionary and a revolutionary step in air transport operations. As a result, new concepts have emerged for UAS traffic management to support the anticipated traffic density growth and the need for safe beyond visual line-of-sight operations. Closely linked with these developments, urban/advanced air mobility (UAM/AAM) has appeared as a new and disruptive dimension for aviation, potentially enabling mobility of goods and people at a different scale compared with current operations, while also emphasizing the need of seamless integration with the existing air traffic management (ATM) framework. These UAS capabilities are reshaping the future of aviation, but also challenge traditional paradigms, requiring significant advances both in technologies and regulations, while keeping strong links with public communities and the perception of societal benefits. As an example, a key role is played by the progress of communications, navigation and surveillance technologies, such as sense-and-avoid and global navigation satellite systems-resilient, alternate position, navigation, and timing systems, and by the seamless integration of airborne and ground infrastructure within a cyber-aware context. Similarly, significant restructuring of the existing regulatory framework is needed to ensure that the integrity and safety of the AAM/ATM integrated airspace is maintained while enabling autonomous operations with higher technological flexibility and refresh rates. In view of these challenges, the AESS Avionics Systems Panel has compiled a special issue of the AESS Magazine whose focus is set on the most recent research and innovation developments in the field of UAM/AAM and UAS airspace integration. This special issue has been kept broad in scope with the aim of providing a wide overview of the state-of-the-art and development trends in the field, while also addressing the main research gaps that are currently being tackled actively by industry, government and academia.
Remote Sensing, 2023
Autonomous navigation (AN) and manoeuvring are increasingly important in distributed satellite sy... more Autonomous navigation (AN) and manoeuvring are increasingly important in distributed satellite systems (DSS) in order to avoid potential collisions with space debris and other resident space objects (RSO). In order to accomplish collision avoidance manoeuvres, tracking and characterization of RSO is crucial. At present, RSO are tracked and catalogued using ground-based observations, but space-based space surveillance (SBSS) represents a valid alternative (or complementary asset) due to its ability to offer enhanced performances in terms of sensor resolution, tracking accuracy, and weather independence. This paper proposes a particle swarm optimization (PSO) algorithm for DSS AN and manoeuvring, specifically addressing RSO tracking and collision avoidance requirements as an integral part of the overall system design. More specifically, a DSS architecture employing hyperspectral sensors for Earth observation is considered, and passive electro-optical sensors are used, in conjunction with suitable mathematical algorithms, to accomplish autonomous RSO tracking and classification. Simulation case studies are performed to investigate the tracking and system collision avoidance capabilities in both space-based and ground-based tracking scenarios. Results corroborate the effectiveness of the proposed AN technique and highlight its potential to supplement either conventional (ground-based) or SBSS tracking methods.
Sensors, 2023
Recent developments in Distributed Satellite Systems (DSS) have undoubtedly increased mission val... more Recent developments in Distributed Satellite Systems (DSS) have undoubtedly increased mission value due to the ability to reconfigure the spacecraft cluster/formation and incrementally add new or update older satellites in the formation. These features provide inherent benefits, such as increased mission effectiveness, multi-mission capabilities, design flexibility, and so on. Trusted Autonomous Satellite Operation (TASO) are possible owing to the predictive and reactive integrity features offered by Artificial Intelligence (AI), including both on-board satellites and in the ground control segments. To effectively monitor and manage time-critical events such as disaster relief missions, the DSS must be able to reconfigure autonomously. To achieve TASO, the DSS should have reconfiguration capability within the architecture and spacecraft should communicate with each other through an Inter-Satellite Link (ISL). Recent advances in AI, sensing, and computing technologies have resulted in the development of new promising concepts for the safe and efficient operation of the DSS. The combination of these technologies enables trusted autonomy in intelligent DSS (iDSS) operations, allowing for a more responsive and resilient approach to Space Mission Management (SMM) in terms of data collection and processing, especially when using state-of-the-art optical sensors. This research looks into the potential applications of iDSS by proposing a constellation of satellites in Low Earth Orbit (LEO) for near-real-time wildfire management. For spacecraft to continuously monitor Areas of Interest (AOI) in a dynamically changing environment, satellite missions must have extensive coverage, revisit intervals, and reconfiguration capability that iDSS can offer. Our recent work demonstrated the feasibility of AI-based data processing using state-of-the-art on-board astrionics hardware accelerators. Based on these initial results, AI-based software has been successively developed for wildfire detection on-board iDSS satellites. To demonstrate the applicability of the proposed iDSS architecture, simulation case studies are performed considering different geographic locations.
44th IEEE Aerospace Conference (AeroConf 2023), 2023
Space debris population has increased dramatically in the past decades posing a threat to the fut... more Space debris population has increased dramatically in the past decades posing a threat to the future of space operations. Traditionally, Resident Space Objects (RSO) are tracked and catalogued using ground-based observations. However, Space Based Space Surveillance (SBSS) is a promising technology to complement the ground-based observations as it offers greater performance in terms of detectability, accuracy and weather independency. A Distributed Satellite System (DSS) architecture is proposed for a SBSS mission equipped with dual-use star trackers and inter-satellite communication links to interact and cooperate with each other to accomplish optimized RSO tracking tasks while assumed to simultaneously perform earth observation tasks.This paper focuses on stereovision-based tracking algorithms with higher detectability and tracking accuracy in SBSS tasks in order to identify an optimal tracking solution for Space Domain Awareness (SDA), which could support future Space Traffic Management (STM) operations. Navigation and tracking uncertainties are analyzed in representative conditions to support the optimal selection and processing of individual observations and to determine the actual confidence region around the detected objects. Additionally, Particle Swarm Optimization (PSO) is implemented on-board the satellites to grant the DSS autonomous trajectory planning and Collision Avoidance (CA) manoeuvring capabilities.
44th IEEE Aerospace Conference (AeroConf 2023), 2023
One of the key challenges that the Advanced Air Mobility (AAM) sector faces is airspace segregati... more One of the key challenges that the Advanced Air Mobility (AAM) sector faces is airspace segregation, which represents a conservative approach to minimize the risk of midair collisions between unmanned and manned aircraft. UAS must have the capabilities to identify, detect and resolve any possible conflicts or collision threats. Sense-and-avoid (SAA) algorithms are responsible for separation assurance and collision avoidance. SAA systems are becoming a requirement for UAS operations. In this paper, we extend the concept of collision avoidance to not only include avoiding a possible impact but also evading possible encounters of wake turbulence from intruder aircraft. This novel approach can greatly increase the capability of SAA by minimizing not only the risk of collision but also the loss of control due to any wake vortices. Moreover, a model for calculating the safe separation distance between different combinations of aircraft based on wake vortices intensity and decay is presented. Real-life effects such as wind turbulence are analyzed to study the effect on the effectiveness of the SAA system. In this paper, we focus on generating avoidance volumes that encapsulate both the hazardous wake and the uncertainty arising from the stochastic nature of wind turbulence. This is simulated as an encounter between two Manned/Unmanned Aerial Vehicles, which resembles a typical interaction scenario in the AAM field.
Australian International Aerospace Congress (AIAC20), 2023
A robust multi-baseline along-track interferometric Synthetic Aperture Radar (SAR) formation flyi... more A robust multi-baseline along-track interferometric Synthetic Aperture Radar (SAR) formation flying concept is proposed to combine effectively several along-track baseline observations for real-time single-pass acquisition purposes. Simulation results are given to support the feasibility of implementing this acquisition mode with autonomous orbit control, using low thrust actuation suitable for electric propulsion. To improve repeatability, a constellation of this formation concept may combine the benefits of these two distributed satellite systems. A maritime domain awareness application is considered as a hypothetical mission to be solved by this combined approach.
Designs, 2023
The accurate modelling and simulation of vehicle dynamics is a fundamental prerequisite for the d... more The accurate modelling and simulation of vehicle dynamics is a fundamental prerequisite for the design and experimental flight testing of aerospace vehicles. In the case of high-altitude supersonic sounding rockets, it is critically important to produce realistic trajectory predictions in a representative range of operational and environmental conditions as well as to produce reliable probability distributions of terminal locations. This article proposes a methodology to develop high-fidelity flight dynamics models that accurately capture aeroelastic, turbulence, atmospheric and other effects relevant to sounding rockets. The significance of establishing a high-fidelity model and of addressing such a problem in the context of developing a digital twin are discussed upfront, together with the key tools utilised in the analysis. In addition to state-of-the-art computational methods to determine the aerodynamic forces, moments and mass changes in various flight regimes (including parachute release), a detailed methodology for incorporating the dynamic aeroelastic response of the rocket is presented. The validity of the proposed method is demonstrated through a simulation case study, which utilises data from an existing rocket prototype. Results corroborate the correct implementation of the proposed algorithms and provide foundations for future research on virtual sensing and digital twin for autonomous navigation and guidance.
Aerospace, 2023
Space-based Earth Observation (EO) systems have undergone a continuous evolution in the twenty-fi... more Space-based Earth Observation (EO) systems have undergone a continuous evolution in the twenty-first century. With the help of space-based Maritime Domain Awareness (MDA), specially Automatic Identification Systems (AIS), their applicability across the world's waterways, among others, has grown substantially. This research work explores the potential applicability of Synthetic Aperture Radar (SAR) and Distributed Satellite System (DSS) for the MDA operation. A robust multi-baseline Along-Track Interferometric Synthetic Aperture Radar (AT-InSAR) formation flying concept is proposed to combine several along-track baseline observations effectively for single-pass interferometry. Simulation results are presented to support the feasibility of implementing this acquisition mode with autonomous orbit control, using low-thrust actuation suitable for electric propulsion. To improve repeatability, a constellation of this formation concept is also proposed to combine the benefits of the DSS. An MDA application is considered as a hypothetical mission to be solved by this combined approach.
Remote Sensing, 2023
One of the United Nations (UN) Sustainable Development Goals is climate action (SDG-13), and wild... more One of the United Nations (UN) Sustainable Development Goals is climate action (SDG-13), and wildfire is among the catastrophic events that both impact climate change and are aggravated by it. In Australia and other countries, large-scale wildfires have dramatically grown in frequency and size in recent years. These fires threaten the world’s forests and urban woods, cause enormous environmental and property damage, and quite often result in fatalities. As a result of their increasing frequency, there is an ongoing debate over how to handle catastrophic wildfires and mitigate their social, economic, and environmental repercussions. Effective prevention, early warning, and response strategies must be well-planned and carefully coordinated to minimise harmful consequences to people and the environment. Rapid advancements in remote sensing technologies such as ground-based, aerial surveillance vehicle-based, and satellite-based systems have been used for efficient wildfire surveillance. This study focuses on the application of space-borne technology for very accurate fire detection under challenging conditions. Due to the significant advances in artificial intelligence (AI) techniques in recent years, numerous studies have previously been conducted to examine how AI might be applied in various situations. As a result of its special physical and operational requirements, spaceflight has emerged as one of the most challenging application fields. This work contains a feasibility study as well as a model and scenario prototype for a satellite AI system. With the intention of swiftly generating alerts and enabling immediate actions, the detection of wildfires has been studied with reference to the Australian events that occurred in December 2019. Convolutional neural networks (CNNs) were developed, trained, and used from the ground up to detect wildfires while also adjusting their complexity to meet onboard implementation requirements for trusted autonomous satellite operations (TASO). The capability of a 1-dimensional convolution neural network (1-DCNN) to classify wildfires is demonstrated in this research and the results are assessed against those reported in the literature. In order to enable autonomous onboard data processing, various hardware accelerators were considered and evaluated for onboard implementation. The trained model was then implemented in the following: Intel Movidius NCS-2 and Nvidia Jetson Nano and Nvidia Jetson TX2. Using the selected onboard hardware, the developed model was then put into practice and analysis was carried out. The results were positive and in favour of using the technology that has been proposed for onboard data processing to enable TASO on future missions. The findings indicate that data processing onboard can be very beneficial in disaster management and climate change mitigation by facilitating the generation of timely alerts for users and by enabling rapid and appropriate responses.
IEEE Geoscience and Remote Sensing Letters, 2022
Climate action (SDG-13) is an integral part of the Sustainable Development Goals (SDGs) set by th... more Climate action (SDG-13) is an integral part of the Sustainable Development Goals (SDGs) set by the United Nations (UN), and wildfire is one of the catastrophic events related to climate change. Large-scale forest fires have drastically increased in frequency and size in recent years in Australia and other nations. These wildfires endanger the forests and urban areas of the world, demolish vast amounts of property, and frequently result in fatalities. There is a requirement for real-time/near realtime catastrophic event monitoring of fires due to their growing frequency. In order to effectively monitor disaster events, it will be feasible to manage them in real-time or near real-time, thanks to the advent of the Distributed Satellite System (DSS). This research examines the possible applicability of DSS for wildfire surveillance. For spacecraft to continually monitor the dynamically changing environment, satellite missions must have broad coverage and revisit intervals that DSS can fulfil. A feasibility analysis, as well as a model and scenario prototype for a satellite Artificial Intelligence (AI) system, are included in this paper to enable prompt action and swiftly provide alerts. In our previous research, it is shown that on-board implementation, i.e., data processing utilising hardware accelerators, is feasible. To enable Trusted Autonomous Satellite Operation (TASO), the same will be included in the proposed DSS architecture, and the outcomes will be provided. To demonstrate the applicability, the suggested DSS architecture will be tested in several geographic locations to demonstrate the system-wide coverage.
FAA/NextGen TechTalk Speaker Series, 2022
This presentation addresses the role of digital avionics, astrionics and Air Traffic Management (... more This presentation addresses the role of digital avionics, astrionics and Air Traffic Management (ATM) systems research in enabling the safe, efficient and sustainable development of the air and space transport sector. The aim is to disseminate recent technological/regulatory advances and to identify opportunities for industrial innovation in strategic areas, such as future Decision Support Systems (DSS) for Intent Based Operations (IBO) and Multi-Domain Traffic Management (MDTM). Starting from SESAR/NextGen top-level requirements, the presentation focusses on integrated Communication, Navigation and Surveillance/ATM and Avionics (CNS+A) system architectures implementing 4-Dimensional Trajectory Optimisation (4DTO) algorithms, data link communications and enhanced surveillance technologies, as well as adaptive cognitive forms of Human-Machine Interface and Interaction (HMI2), allowing the automated negotiation and validation of aircraft intents for safer and more efficient ATM operations. As an integral part of this CNS+A evolutionary process, specific requirements for Unmanned Aircraft Systems (UAS) navigation, communication and cooperative/non-cooperative Sense-and-Avoid (SAA) are being addressed in order to allow the safe and unrestricted access of UAS to all classes of airspace. In parallel with air transport developments, progress in spaceflight research has led to the introduction of various manned and unmanned reusable space vehicle concepts, opening up uncharted opportunities for the newborn space transport industry. For future space transport operations to be technically and commercially viable, it is critical that an acceptable level of safety is provided, requiring the development of novel digital tools (e.g., mission planning and decision support systems) that utilize advanced CNS+A technologies, and allowing a seamless integration of space operations in the current ATM network. While the technical maturity of propulsive and vehicle technologies is relatively high, a recent review of emerging platform operational concepts highlights the challenges (and opportunities) brought in by the adoption of cyber-physical and autonomous systems for integration of point-to-point suborbital spaceflight with conventional atmospheric air transport. In particular, various viable launch and re-entry methodologies were addressed, where the physical and computational limitations of these approaches was identified and applicability to future commercial space transport operations was assessed. Recent research is turning greater attention to the on-orbit phase, where the unique hazards of the space environment are being examined and the necessary elements required for space object de-confliction and collision avoidance modelling are analysed. The evolution of regulatory frameworks supporting spacecraft operations is a conspicuous factor, which requires a holistic approach and extensive government support for the successful development and establishment of sustainable business models, including space debris mitigation strategies, operational risk assessment and liability issues. Within the atmospheric domain, extensions and alternatives to the conventional airspace segregation approaches must be identified including ATM/ATFM techniques to facilitate the integration of new-entrant platforms. Lastly, adequate modelling approaches to meet on-orbit risk criteria must be developed and evolutionary requirements to improve current operational procedures (and associated regulatory frameworks) must be addressed in order to establish a fully-integrated Multi-Domain Traffic Management (MDTM) framework.
IEEE International Conference on Metrology for Extended Reality, Artificial Intelligence and Neural Engineering (MetroXRAINE), 2022
This paper investigates the opportunity to use artificial intelligence methodologies and edge com... more This paper investigates the opportunity to use artificial intelligence methodologies and edge computing approaches for wildfire detection directly from satellite platforms. The test case for our study is PRISMA (Precursore IperSpettrale della Missione Applicativa-Hyperspectral Precursor of the Application Mission), the Italian hyperspectral satellite launched in 2019 by the Italian Space Agency. This mission provides hyperspectral (HS) images in the spectral range of [0.4,2.5] μm and an average spectral resolution less than 10 nm. This work reports new results related to the Australian bushfires happened in December 2019 in New South Wales, captured by PRISMA on December 27, 2019. Starting from a one-dimensional convolutional neural network (CNN) discussed in previous authors’ works to perform multiclass classification, this paper primarily deals with the opportunity to use hardware accelerators, namely the Intel Movidius Myriad 2, the Nvidia Jetson TX2, and the Nvidia Jetson Nano, to consider the on-the-edge implementation of the CNN. This study is in line with the current impulse to improve on-board computing capabilities and platform autonomy, setting some of the elements for future satellites or constellations focusing on specific remote sensing tasks to provide real-time reliable early warnings.
IEEE/AIAA 41st Digital Avionics Systems Conference (DASC)
Satellite technologies are used for both civil and military purposes in the modern world, and typ... more Satellite technologies are used for both civil and military purposes in the modern world, and typical applications include Communication, Navigation and Surveillance (CNS) services, which have a direct impact several economic, social and environmental protection activity. The increasing reliance on satellite services for safety-of-life and mission-critical applications (e.g., transport, defense and public safety services) creates a severe, although often overlooked, security problem, particularly when it comes to cyber threats. Like other increasingly digitized services, satellites and space platforms are vulnerable to cyberattacks. Thus, the existence of cybersecurity flaws may pose major threats to space-based assets and associated key infrastructure on the ground. These dangers could obstruct global economic progress and, by implication, international security if they are not properly addressed. Mega-constellations make protecting space infrastructure from cyberattacks much more difficult. This emphasizes the importance of defensive cyber countermeasures to minimize interruptions and ensure efficient and reliable contributions to critical infrastructure operations. Very importantly, space systems are inherently complex Cyber-Physical System (CPS) architectures, where communication, control and computing processes are tightly interleaved, and associated hardware/software components are seamlessly integrated. This represents a new challenge as many known physical threats (e.g., conventional electronic warfare measures) can now manifest their effects in cyberspace and, vice-versa, some cyber-threats can have detrimental effects in the physical domain. The concept of cyberspace underlies nearly every aspect of modern society's critical activities and relies heavily on critical infrastructure for economic advancement, public safety and national security. Many governments have expressed the desire to make a substantial contribution to secure cyberspace and are focusing on different aspects of the evolving industrial ecosystem, largely under the impulse of digital transformation and sustainable development goals. The level of cybersecurity attained in this framework is the sum of all national and international activities implemented to protect all actions in the cyber-physical ecosystem. This paper focuses on cybersecurity threats and vulnerabilities in various segments of space CPS architectures. More specifically, the paper identifies the applicable cyber threat mechanisms, conceivable threat actors and the associated space business implications. It also presents metrics and strategies for countering cyber threats and facilitating space mission assurance.
Wiley Aerospace Series (Book) - John Wiley & Sons, 2023
Sustainable Aviation Technology and Operations provides an updated and timely outlook of recent r... more Sustainable Aviation Technology and Operations provides an updated and timely outlook of recent research in aeronautics and air transport, with emphasis on current environmental objectives and achievements. The book discusses some of the most promising advances in sustainable aircraft and air traffic management technologies including: aircraft systems, aerodynamics, propulsion, structures, materials, biofuels, autonomous systems, air traffic flow management and dynamic airspace management. The physical processes associated with production and environmental impacts of various aircraft emissions, including air pollutants, noise and contrails, are presented to support the development of computational models for aircraft design, mission planning and trajectory optimisation. Relevant advances in systems engineering and lifecycle management processes are also covered, identifying the existing gaps in both academic research and industry best practices towards developing viable solutions. A set of research case studies concludes and complements the book, addressing aircraft design, systems design and mission optimisation for a more efficient and environmentally sustainable air transport.