arXiv subjects

Domingos Barbosa

Publications and source records attributed to Domingos Barbosa.

At least 19 recordsLinked to original sources

arXiv2026

A First Africa Wide Amateur Radio Contact Experiment with the International Space Station

The Amateur Radio on the International Space Station (ARISS) program is recognized by its great Science, Technology, Engineering, and Mathematics (STEM) impact: it brings space science to education and outreach initiatives by enabling direct contact with astronauts in orbit and other space savvy professionals. Strategic partnerships between ARISS and digital platforms for citizen science act as a powerful real-world STEM motivator and can overcome logistical barriers, demonstrating a scalable model for inclusive outreach, sparking curiosity in space exploration and STEM careers among underrepresented communities. As a case study, this article focus on the impact of an historic milestone: on April 18$^{th}$ 2025 the Pan-African Citizen Science e-Laboratory (PACS e-Lab) orchestrated the first Africa-wide ARISS contact experiment and connected 300 students, educators, and STEM enthusiasts from 38 African nations and beyond with NASA astronaut Nichole Ayers aboard the ISS Expedition 72. Within the African context, this initiative not only inspired a new generation of African scientists, but it also set a precedent for wider collaboration on space science education across the continent. Strategic partnership between ARISS and PACs e-LAB promotes capacity building through international and regional cooperation on space science and adds a new "New Space" narrative that emphasizes the interconnectedness of space with our daily lives and the possibility that everyone has to be a part of it.

physics.ed-ph↗

arXiv2025

A Cloud-native Agile approach to cyber platform prototyping and integration for astronomy: the ENGAGE SKA case

The Square Kilometre Array (SKA) Observatory is gearing up the formal construction of its two radio interferometers in Australia and South Africa after the end of design and pre-construction phases. Agile methodologies, the Cloud native Computing technologies and the DevOps software ideas are influencing the design of compute infrastructures that will be key to reduce the operational costs of SKA while improving the control and monitoring of the SKA antennas and ancillary systems, Correlators, HPC facilities or related data centre tiered systems. These tools will likely include advanced power metering technologies and efficient distribution automation and Network Operation Centres (NOC). SKA will become the world's largest radio telescope and is expected to achieve its first science by 2026. To cope with this dimension and complexity, a key part of this distributed Observatory is the overall software control and monitoring system embodied in the Observatory Management and Control (OMC) and the Services Teams that requires specialized Agile Teams to assist in software and cyber infrastructure building using an Agile development environment that includes test automation, Continuous Integration, and Continuous Deployment. To manage such a large and distributed machine, the Agile approach was adopted for the core software package of the SKA Telescope aimed at scheduling observations, controlling their execution, monitoring the telescope status and ensuring scalability and reliability. Here, we report on the ENGAGE SKA ciberinfrastructure prototyping support to the SKA Agile Software Development Life Cycle (SDLC).

astro-ph.IM↗

arXiv2025

Call to Protect the Dark and Quiet Sky from Harmful Interference by Satellite Constellations

The growing number of satellite constellations in low Earth orbit (LEO) enhances global communications and Earth observation, and support of space commerce is a high priority of many governments. At the same time, the proliferation of satellites in LEO has negative effects on astronomical observations and research, and the preservation of the dark and quiet sky. These satellite constellations reflect sunlight onto optical telescopes, and their radio emission impacts radio observatories, jeopardising our access to essential scientific discoveries through astronomy. The changing visual appearance of the sky also impacts our cultural heritage and environment. Both ground-based observatories and space-based telescopes in LEO are affected, and there are no places on Earth that can escape the effects of satellite constellations given their global nature. The minimally disturbed dark and radio-quiet sky is crucial for conducting fundamental research in astronomy and important public services such as planetary defence, technology development, and high-precision geolocation. Some aspects of satellite deployment and operation are regulated by States and intergovernmental organisations. While regulatory agencies in some States have started to require operators to coordinate with their national astronomy agencies over impacts, mitigation of the impact of space objects on astronomical activities is not sufficiently regulated. To address this issue, the CPS urges States and the international community to take steps to protect the dark and quiet sky as specified in this paper.

astro-ph.IM↗

arXiv2024

CLOWN: The PASO cloud detection for optimization of automatic optical surveys

Orbiting space objects have become in the last decade a major nuisance impacting ground astronomy and orbiting space assets, from observatories to satellites and space stations. In particular with the rise of the satellite population in Low Earth Orbits (LEOs), space objects are becoming an even bigger threat and a strong problem to astronomical observations. To tackle these threats several coordinated surveillance networks composed of dedicated sensors (telescopes, radars and laser ranging facilities) track and survey space objects, from debris to active satellites. As part of the European Space Surveillance \& Tracking (EU-SST) network, Portugal is developing the PAmpilhosa da Serra Space Observatory (PASO), with both radio and optical telescopes dedicated to the Space Situational Awareness (SSA) domain, deployed at a Dark Sky destination. To optimize telescope survey time, we developed {\tt{CLOWN}} (CLOud Watcher at Night), an application interface that automatically monitors clouds in real time. This software can correctly trace clouds positions in the sky, provides accurate pointing information to the observation planning of the optical telescope to avoid cloudy areas. {\tt{CLOWN}} only requires the use of an all-sky camera, which is already a norm in observatories with optical telescopes and can be used with any camera, including those for which no information about its model specification do exist. {\tt{CLOWN}} does not require great computing power and it does not require the installation of additional equipment. {\tt{CLOWN}} results are very promising and confirm that the app can correctly identify clouds in a variety of different conditions and cloud types.

astro-ph.IM↗

arXiv2024

PASO -- Astronomy and Space Situational Awareness in a Dark Sky Destination

The Pampilhosa da Serra Space Observatory (PASO) is located in the center of the continental Portuguese territory, in the heart of a certified Dark Sky destination by the Starlight Foundation (Aldeias do Xisto) and has been an instrumental asset to advance science, education and astrotourism certifications. PASO hosts astronomy and Space Situational Awareness (SSA) activities including a node of the Portuguese Space Surveillance \& Tracking (SST) infrastructure network, such as a space radar currently in test phase using GEM radiotelescope, a double Wide Field of View Telescope system, a EUSST optical sensor telescope. These instruments allow surveillance of satellite and space debris in LEO, MEO and GEO orbits. The WFOV telescope offers spectroscopy capabilities enabling light curve analysis and cosmic sources monitoring. Instruments for Space Weather are being considered for installation to monitor solar activities and expand the range of SSA services.

astro-ph.IM↗

arXiv2023

Theory of Functional Connections and Nelder-Mead optimization methods applied in satellite characterization

The growing population of man-made objects with the build up of mega-constellations not only increases the potential danger to all space vehicles and in-space infrastructures (including space observatories), but above all poses a serious threat to astronomy and dark skies. Monitoring of this population requires precise satellite characterization, which is is a challenging task that involves analyzing observational data such as position, velocity, and light curves using optimization methods. In this study, we propose and analyze the application of two optimization procedures to determine the parameters associated with the dynamics of a satellite: one based on the Theory of Functional Connections (TFC) and another one based on the Nelder-Mead heuristic optimization algorithm. The TFC performs linear functional interpolation to embed the constraints of the problem into a functional. In this paper, we propose to use this functional to analytically embed the observational data of a satellite into its equations of dynamics. After that, any solution will always satisfy the observational data. The second procedure proposed in this research takes advantage of the Nealder-Mead algorithm, that does not require the gradient of the objective function, as alternative solution. The accuracy, efficiency, and dependency on the initial guess of each method is investigated, analyzed, and compared for several dynamical models. These methods can be used to obtain the physical parameters of a satellite from available observational data and for space debris characterization contributing to follow-up monitoring activities in space and astronomical observatories.

astro-ph.IM↗

arXiv2023

ATLAS: Deployment, Control Platform and First RSO Measurements

The ever increasing dependence of modern societies in space based services results in a rising number of objects in orbit which grows the probability of collisions between them. The increase in space debris is a threat to space assets, space based-operations and led to a common effort to develop programs for dealing with it. As part of the Portuguese Space Surveillance and Tracking (SST) project, led by the Portuguese Ministry of Defense (MoD), Instituto de Telecomunicações (IT) is developing the rAdio TeLescope pAmpilhosa Serra (ATLAS), a new monostatic radar tracking sensor located at the Pampilhosa da Serra Space Observatory (PASO), Portugal. The system operates at 5.56 GHz and aims to provide information on objects in low earth orbit (LEO), with cross sections above 10 cm$^2$ at 1000~km. The sensor is tasked by the Portuguese Network Operations Center (NOC), located in the Azores island, which interfaces with the EU-SST network.

physics.space-ph↗

arXiv2022

Developing a data fusion concept for radar and optical ground based SST station

As part of the Portuguese Space Surveillance and Tracking (SST) program, a tracking radar and a double Wide Field of View Telescope system (4.3° x 2.3°) are being installed at the Pampilhosa da Serra Space Observatory (PASO) in the centre of continental Portugal, complementing an already installed deployable optical sensor for MEO and GEO surveillance. The tracking radar will track space debris in Low Earth Orbit (LEO) up to 1000 km and at the same time the telescope will also have LEO tracking capabilities. This article intends to discuss possible ways to take advantage of having these two sensors at the same location. Using both types of sensors takes advantage of the radar measurements which give precise radial velocity and distance to the objects, while the telescope gives better sky coordinates measurements. With the installation of radar and optical sensors, PASO can extend observation time of space debris and correlate information from optical and radar provenances in real time. During twilight periods both sensors can be used simultaneously to rapidly compute new TLEs for LEO objects, eliminating the time delays involved in data exchange between sites in a large SST network. This concept will not replace the need for a SST network with sensors in multiple locations around the globe, but will provide a more complete set of measurements from a given object passage, and therefore increase the added value for initial orbit determination, or monitoring of reentry campaigns of a given location. PASO will contribute to the development of new solutions to better characterize the objects improving the overall SST capabilities and constitute a perfect site for the development and testing of new radar and optical data fusion algorithms and techniques for space debris monitoring.

astro-ph.IM↗

arXiv2022

A Portuguese radar tracking sensor for Space Debris monitoring

The increase in space debris is a threat to space assets, space based-operations and led to a common effort to develop programs for dealing with this increase. As part of the Portuguese Space Surveillance and Tracking (SST) project, led by the Portuguese Ministry of Defense (MoD), the Instituto de Telecomunicações (IT) is developing rAdio TeLescope pAmpilhosa Serra (ATLAS), a new monostatic radar tracking sensor located at the Pampilhosa da Serra Space Observatory (ErPoB), Portugal. The system operates at 5.56 GHz and aims to provide information on objects in low earth orbit (LEO) orbits, with cross sections above 10 cm2 at 1000 km. ErPoB houses all the necessary equipment to connect to the research and development team in IT-Aveiro and to the European Union Space Surveillance and Tracking (EU-SST) network through the Portuguese SST-PT network and operation center. The ATLAS system features digital waveform synthesis, power amplifiers using Gallium Nitride (GaN) technology, fully digital signal processing and a highly modular architecture that follows an Open Systems (OS) philosophy and uses Commercial-Off-The-Shelf (COTS) technologies. ATLAS establishes a modern and versatile platform for fast and easy development, research and innovation. The whole system (except antenna and power amplifiers) was tested in a setup with a major reflector of opportunity at a well defined range. The obtained range profiles show that the target can be easily detected. This marks a major step on the functional testing of the system and on getting closer to an operational system capable of detecting objects in orbit.

astro-ph.IM↗

arXiv2021

Cyber-Cosmos: A New Citizen Science Concept in A Dark Sky Destination

Astrotourism and related citizen science activities are becoming a major trend of a sustainable, high-quality tourism segment, core elements to the protection of Dark skies in many countries. In the Summer of 2020, in the middle of COVID pandemics, we started an initiative to train young students - Cyber-Cosmos - using an Unistellar eVscope, a smart, compact and user-friendly digital telescope that offers unprecedented opportunities for deep-sky observation and citizen science campaigns. Sponsored by the Ciência Viva Summer program, this was probably the first continuous application of this equipment in a pedagogical and citizen-science context, and in a pandemic context. Pampilhosa da Serra, home to a certified Dark Sky destination (Aldeias do Xisto) in central Portugal, was the chosen location for this project, where we expect astrotourism and citizen science to flourish and contribute to space sciences education.

physics.soc-ph↗

arXiv2021

Radio astronomy and Space science in Azores: enhancing the Atlantic VLBI infrastructure cluster

Radio astronomy and Space Infrastructures in the Azores have a great scientific and industrial interest because they benefit from a unique geographical location in the middle of the North Atlantic allowing a vast improvement in the sky coverage. This fact obviously has a very high added value for: i) the establishment of space tracking and communications networks for the emergent global small satellite fleets ii) it is invaluable to connect the radio astronomy infrastructure networks in Africa, Europe and America continents using Very Large Baseline Interferometry (VLBI) techniques, iii) it allows excellent potential for monitoring space debris and Near Earth Objects (NEOs). There is in S. Miguel island a 32-metre SATCOM antenna that could be integrated in advanced VLBI networks and be capable of additional Deep Space Network ground support. This paper explores the space science opportunities offered by the upgrade of the S. Miguel 32-metre SATCOM antenna into a world-class infrastructure for radio astronomy and space exploration: it would enable a Deep Space Network mode and would constitute a key space facility for data production, promoting local digital infrastructure investments and the testing of cutting-edge information technologies. Its Atlantic location also enables improvements in angular resolution, provides many baseline in East-West and North-South directions connecting the emergent VLBI stations in America to Europe and Africa VLBI arrays therefore contributing for greater array imaging capabilities especially for sources or well studied fields close to or below the celestial equator, where ESO facilities, ALMA, SKA and its precursors do or will operate and observe in the coming decades.

astro-ph.IM↗

arXiv2021

Design of pulsed waveforms for space debris detection with ATLAS

ATLAS is the first Portuguese radar system that aims to detect space debris. The article introduces the system and provides a brief description of its capabilities. The system is capable of synthesizing arbitrary amplitude modulated pulse shapes with a resolution of 10 ns. Given that degree of freedom we decided to test an amplitude modulated chirp signal developed by us and a nested barker code. These waveforms are explained as well as their advantages and drawbacks for space debris detection. An experimental setup was developed to test the system receiver and waveforms are processed by digital matched filtering. The experiments test the system using different waveform shapes and noise levels. Experimental results are in agreement with simulation and show that the chirp signal is more resilient to Doppler shifts, has higher range resolution and lower peak-to-sidelobe ratio in comparison with the nested barker code. Future work in order to increase detection capabilities is discussed at the end.

astro-ph.IM↗

arXiv2021

New SST Optical Sensor of Pampilhosa da Serra: studies on image processing algorithms and multi-filter characterization of Space Debris

As part of the Portuguese Space Surveillance and Tracking (SST) System, two new Wide Field of View (2.3deg x 2.3deg) small aperture (30cm) telescopes will be deployed in 2021, at the Pampilhosa da Serra Space Observatory (PASO), located in the center of the continental Portuguese territory, in the heart of a certified Dark Sky area. These optical systems will provide added value capabilities to the Portuguese SST network, complementing the optical telescopes currently in commissioning in Madeira and Azores. These telescopes are optimized for GEO and MEO survey operations and besides the required SST operational capability, they will also provide an important development component to the Portuguese SST network. The telescopes will be equipped with filter wheels, being able to perform observations in several optical bands including white light, BVRI bands and narrow band filters such as H(alpha) and O[III] to study potential different objects' albedos. This configuration enables us to conduct a study on space debris classification$/$characterization using combinations of different colors aiming the production of improved color index schemes to be incorporated in the automatic pipelines for classification of space debris. This optical sensor will also be used to conduct studies on image processing algorithms, including source extraction and classification solutions through the application of machine learning techniques. Since SST dedicated telescopes produce a large quantity of data per observation night, fast, efficient and automatic image processing techniques are mandatory. A platform like this one, dedicated to the development of Space Surveillance studies, will add a critical capability to keep the Portuguese SST network updated, and as a consequence it may provide useful developments to the European SST network as well.

astro-ph.IM↗

arXiv2021

Development of the first Portuguese radar tracking sensor for Space Debris

Currently, space debris represents a threat for satellites and space-based operations, both in-orbit and during the launching process. The yearly increase in space debris represents a serious concern to major space agencies leading to the development of dedicated space programs to deal with this issue. Ground-based radars can detect Earth orbiting debris down to a few square centimeters and therefore constitute a major building block of a space debris monitoring system. New radar sensors are required in Europe to enhance capabilities and availability of its small radar network capable of tracking and surveying space objects and to respond to the debris increase expected from the New Space economy activities. This article presents ATLAS, a new tracking radar system for debris detection located in Portugal. It starts by an extensive technical description of all the system components followed by a study that estimates its future performance. A section dedicated to waveform design is also presented, since the system allows the usage of several types of pulse modulation schemes such as LFM and phase coded modulations while enabling the development and testing of more advanced ones. By presenting an architecture that is highly modular with fully digital signal processing, ATLAS establishes a platform for fast and easy development, research and innovation. The system follows the use of Commercial-Off-The-Shelf technologies and Open Systems which is unique among current radar systems.

physics.space-ph↗

arXiv2020

Portuguese SKA White Book

This white book stems from the contributions presented at the Portuguese SKA Days, held on the 6th and 7th February 2018 with the presence of the SKA Deputy Director General Alistair McPherson and the SKA Science Director Robert Braun. This initiative was held to promote the Square Kilometer Array (SKA) - the world's largest radio telescope - among the Portuguese scientific and business communities with support from the Portuguese Science and Technology Foundation (FCT) with the contribution of Portuguese policy makers and researchers. The meeting was very successful in providing a detailed overview of the SKA status, vision and goals and describes most of the Portuguese contributions to science, technology and the related industry aspirations

astro-ph.IM↗

arXiv2018

BIOSTIRLING-4SKA : A cost effective and efficient approach for a new generation of solar dish-Stirling plants based on storage and hybridization; An Energy demo project for Large Scale Infrastructures",

The BIOSTIRLING - 4SKA (B4S) is a EU demonstration project dealing with the implementation of a cost-effective and efficient new generation of solar dish-Stirling plants based on hybridization and efficient storage at the industrial scale. The main goal of the B4S demonstration project is the generation of electric power using simultaneously solar power and gas to supply an isolated system and act as a scalable example of potential power supply for many infrastructures, including future sustainable large scientific infrastructures. B4S build an interdisciplinary approach to address reliability, maintainability and costs of this technology. In April 2017, B4S successfully tested in Portugal the first world Stirling hybrid system providing about 4kW of power to a phased array of antennas, overcoming challenges in Stirling and hybridization and smartgrid technologies. B4SKA Consortium, with fourteen companies from six European countries, has performed the engineering, construction, assembly and experimental exploitation, under contract signed with the European to develop on off-grid demonstrator in Contenda (Moura) Portugal.

astro-ph.IM↗

arXiv2016

A Cyber Infrastructure for the SKA Telescope Manager

The Square Kilometre Array Telescope Manager (SKA TM) will be responsible for assisting the SKA Operations and Observation Management, carrying out System diagnosis and collecting Monitoring & Control data from the SKA sub-systems and components. To provide adequate compute resources, scalability, operation continuity and high availability, as well as strict Quality of Service, the TM cyber-infrastructure (embodied in the Local Infrastructure - LINFRA) consists of COTS hardware and infrastructural software (for example: server monitoring software, host operating system, virtualization software, device firmware), providing a specially tailored Infrastructure as a Service (IaaS) and Platform as a Service (PaaS) solution. The TM infrastructure provides services in the form of computational power, software defined networking, power, storage abstractions, and high level, state of the art IaaS and PaaS management interfaces. This cyber platform will be tailored to each of the two SKA Phase 1 telescopes (SKA_MID in South Africa and SKA_LOW in Australia) instances, each presenting different computational and storage infrastructures and conditioned by location. This cyber platform will provide a compute model enabling TM to manage the deployment and execution of its multiple components (observation scheduler, proposal submission tools, M&C components, Forensic tools and several Databases, etc). In this sense, the TM LINFRA is primarily focused towards the provision of isolated instances, mostly resorting to virtualization technologies, while defaulting to bare hardware if specifically required due to performance, security, availability, or other requirement.

astro-ph.IM↗

arXiv2016

Power Monitoring and Control for Large Scale projects: SKA, a case study

Large sensor-based science infrastructures for radio astronomy like the SKA will be among the most intensive data-driven projects in the world, facing very high demanding computation, storage, management, and above all power demands. The geographically wide distribution of the SKA and and its associated processing requirements in the form of tailored High Performance Computing (HPC) facilities, require a Greener approach towards the Information and Communications Technologies (ICT) adopted for the data processing to enable operational compliance to potentially strict power budgets. Addressing the reduction of electricity costs, improve system power monitoring and the generation and management of electricity at system level is paramount to avoid future inefficiencies and higher costs and enable fulfillments of Key Science Cases. Here we outline major characteristics and innovation approaches to address power efficiency and long-term power sustainability for radio astronomy projects, focusing on Green ICT for science and Smart power monitoring and control.

astro-ph.IM↗