New robust approaches to designing large radio research instruments

Modern radio telescopes, like the proposed Square Kilometre Array (SKA), are extremely sensitive and the faint signals they receive can easily be contaminated irreversibly by stray radio frequency interference (RFI). Understanding how radio telescope performance is degraded by RFI is important. In this paper we describe an RFI simulation framework that can be used to generate test stimulus and verify a telescope’s performance. The framework can be used during design to investigate the impact of various RFI scenarios and develop mitigation strategies. As well, it can be used to exercise and test hardware firmware after a system is installed. A prototype of the framework was implemented in the Python computer language to demonstrate the key concepts. Additionally, we outline the framework requirements, describe a suitable software structure and discuss a prototype implementation. As well, we present measurements made to verify the software generates correct test stimulus, for RFI from aircraft distance measuring equipment (DME). The work described was carried out to evaluate the impact of RFI on the Square Kilometre Array, an international effort to build the largest most sensitive radio telescope.

This paper will report on the progress in the research field of radio astronomy in Malaysia and also in South-East Asia. Radio astronomy research can be said to have only started being done actively in Malaysia in 2005. Fundamental setup and some basic research were done in the early parts. Jupiter radio bursts as well as radio meteor counting were the first few projects. Currently a medium-sized radio telescope which was recently purchased is being used to undergo more advanced research such as observing spectrum of galaxy clusters in order to study Dark Matter. This paper will also report on the latest results on the survey of Radio Frequency Interference (RFI), which is currently done on chosen candidate sites in Malaysia in order to setup on it a large radio telescope in the future. The best site with the lowest averaged RFI level is found at Langkawi (−100.33 dBm or 4.4 × 106 Jy). The author is the chair for the Radio Astronomy Working Group for the South-East Asia Astronomy Network (SEAAN) and the Malaysian team is very much an important part of this group. This group will eventually be a research hub for the global projects of the Global-Very Long Baseline Interferometer (Global-VLBI) and the Square Kilometre Array (SKA).

We report the first measurements of radio frequency spectrum occupancy performed at sites aimed to host the future radio astronomy observatory in Indonesia. The survey is intended to obtain the radio frequency interference (RFI) environment in a spectral range from low frequency 10 MHz up to 8 GHz. The measurements permit the identification of the spectral occupancy over those selected sites in reference to the allocated radio spectrum in Indonesia. The sites are in close proximity to Australia, the future host of Square Kilometre Array (SKA) at low frequency. Therefore, the survey was deliberately made to approximately adhere the SKA protocol for RFI measurements, but with lower sensitivity. The RFI environment at Bosscha Observatory in Lembang was also measured for comparison. Within the sensitivity limit of the measurement equipment, it is found that a location called Fatumonas in the surrounding of Mount Timau in West Timor has very low level of RFI, with a total spectrum occupancy in this measured frequency range being about 1 %, mostly found at low frequency below 20 MHz. More detailed measurements as well as a strategy for a radio quiet zone must be implemented in the near future.

The Square Kilometre Array (SKA) project is responsible for developing the SKA Observatory, the world’s largest radio telescope, with eventually over a square kilometre of collecting area and including a general headquarters as well as two radio telescopes: SKA1-Mid in South Africa and SKA1-Low in Australia. The SKA project consists of a number of subsystems (elements) among which the Telescope Manager (TM) is the one involved in controlling and monitoring the SKA telescopes. The TM element has three primary responsibilities: management of astronomical observations, management of telescope hardware and software subsystems, management of data to support system operations and all stakeholders (operators, maintainers, engineers and science users) in achieving operational, maintenance and engineering goals. Operators, maintainers, engineers and science users will interact with TM via appropriate user interfaces (UI). The TM UI framework envisaged is a complete set of general technical solutions (components, technologies and design information) for implementing a generic computing system (UI platform). Such a system will enable UI components to be instantiated to allow for human interaction via screens, keyboards, mouse and to implement the necessary logic for acquiring or deriving the information needed for interaction. It will provide libraries and specific Application Programming Interfaces (APIs) to implement operator and engineer interactive interfaces. This paper will provide a status update of the TM UI framework, UI platform and UI components design effort, including the technology choices, and discuss key challenges in the TM UI architecture, as well as our approaches to addressing them.

The Square Kilometre Array (SKA), a flagship 21st-century radio astronomy project [1], necessitates a global distributed network of SKA Regional Centres (SRCs) to address its unprecedented data processing, storage, and distribution needs [2,3].The China SKA Regional Centre (cnSRC) is under development as a critical component of the international SRCNet, this system architecture is designed to flexibly support both High-Performance-Computing (HPC) and Kubernetes container orchestration, enable scientific data access for the Chinese and broader international astronomy communities [4].This presentation provides and overview of the cnSRC's current status, cncompassing its computing infrastructure, data processing capabilities, data management and distribution strategies, scientific research priorities, and user support services [3].We introduce the cnSRC's architecture, strategy, and implementation progress, focusing on the deployment of federated computing models, high-speed networking solutions, and scalable data management systems.Furthermore, we discuss the development of the software framework and data pipelines designed to support SKA workflows, including data ingestion, processing, visualization, and user interaction.By aligning with SKA's global SRC architecture and policies, cnSRC aims to provide a robust and efficient platform for enabling SKA science in China and beyond.We also highlight the robust collaborative framework emerging among Asia-Pacific SKA Regional Centres, with a particular focus on the strong partnership between China and Australia in advancing radio astronomy, demonstrating the region's collective commitment.

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).

The Square Kilometre Array (SKA) will be the largest radio astronomy observatory ever built, providing unprecedented sensitivity over a very broad frequency band from 50 MHz to 15.3 GHz. The SKA’s low frequency component (SKA-Low), which will observe in the 50–350 MHz band, will be built at the Murchison Radio-astronomy Observatory (MRO) in Western Australia. It will consist of 512 stations each composed of 256 dual-polarised antennas, and the sensitivity of an individual station is pivotal to the performance of the entire SKA-Low telescope. The answer to the question in the title is, it depends. The sensitivity of a low frequency array, such as an SKA-Low station, depends strongly on the pointing direction of the digitally formed station beam and the local sidereal time (LST), and is different for the two orthogonal polarisations of the antennas. The accurate prediction of the SKA-Low sensitivity in an arbitrary direction in the sky is crucial for future observation planning. Here, we present a sensitivity calculator for the SKA-Low radio telescope, using a database of pre-computed sensitivity values for two realisations of an SKA-Low station architecture. One realisation uses the log-periodic antennas selected for SKA-Low. The second uses a known benchmark, in the form of the bowtie dipoles of the Murchison Widefield Array. Prototype stations of both types were deployed at the MRO in 2019, and since then have been collecting commissioning and verification data. These data were used to measure the sensitivity of the stations at several frequencies and over at least 24 h intervals, and were compared to the predictions described in this paper. The sensitivity values stored in theSQLitedatabase were pre-computed for the X, Y, and Stokes I polarisations in 10 MHz frequency steps,$\scriptsize{1/2}$hour LST intervals, and$5^\circ$resolution in pointing directions. The database allows users to quickly and easily estimate the sensitivity of SKA-Low for arbitrary observing parameters (your favourite object) using interactive web-based or command line interfaces. The sensitivity can be calculated using publicly available web interface (http://sensitivity.skalow.link) or a command linepythonpackage (https://github.com/marcinsokolowski/station_beam), which can also be used to calculate the sensitivity for arbitrary pointing directions, frequencies, and times without interpolations.

This industry paper describes two contemporary investigations with strong electromagnetic compatibility (EMC) requirements in South Africa:•new installation magnetic noise evaluation at the South African National Space Agency (SANSA) Space Science Centre (former Hermanus Magnetic Observatory) and,•stringent shielding effectiveness (SE) testing of the MeerKAT Telescope Array, which will form part of the international Square Kilometre Array (SKA) developments.

The next generation interferometric radio telescope, the Square Kilometre Array (SKA), which will be the most sensitive and largest radio telescope ever constructed, could greatly contribute to the detection, survey and characterization of Gamma Ray Bursts (GRBs). By the SKA, it will be possible to perform the follow up of GRBs even for several months. This approach would be extremely useful to extend the Spectrum Energetic Distribution (SED) from the gamma to the to radio band and would increase the number of radio detectable GRBs. In principle, the SKA could help to understand the physics of GRBs by setting constraints on theoretical models. This goal could be achieved by taking into account multiple observations at different wavelengths in order to obtain a deeper insight of the sources. Here, we present an estimation of GRB radio detections, showing that the GRBs can really be observed by the SKA. The approach that we present consists in determining blind detection rates derived by a very large sample consisting of merging several GRB catalogues observed by current missions as Swift, Fermi, Agile and INTEGRAL and by previous missions as BeppoSAX, CGRO, GRANAT, HETE-2, Ulysses and Wind. The final catalogue counts 7516 distinct sources. We compute the fraction of GRBs that could be observed by the SKA at high and low frequencies, above its observable sky. Considering the planned SKA sensitivity and through an extrapolation based on previous works and observations, we deduce the minimum fluence in the range 15-150 keV. This is the energy interval where a GRB should emit to be detectable in the radio band by the SKA. Results seem consistent with observational capabilities.

During the International Year of Astronomy in 2009, we initiated a collaboration between astrophysicists in Western Australia working toward building the largest telescope on Earth, the Square Kilometre Array (SKA), and Indigenous artists living in the region where the SKA is to be built. We came together to explore deep traditions in Indigenous culture, including perspectives of the night sky, and the modern astrophysical understanding of the Universe. Over the course of the year, we travelled as a group and camped at the SKA site, we sat under the stars and shared stories about the constellations, and we talked about the telescopes we wanted to build and how they could sit on the Indigenous traditional country. We found lots of interesting points of connection in our discussions and both artists and astronomers found inspiration. The artists then produced <150 original works of art, curated as an exhibition called “Ilgarijiri — Things belonging to the Sky” in the language of the Wadjarri Yamatji people. This was exhibited in Geraldton, Perth, Canberra, South Africa, Brussels, the U.S.A., and Germany over the course of the next few years. In 2015, the concept went further, connecting with Indigenous artists from South Africa, resulting in the “Shared Sky” exhibition, which now tours the ten SKA member countries. The exhibitions communicate astrophysics and traditional Indigenous stories, as well as carry to the world Indigenous culture and art forms. The process behind the collaboration is an example of the Reconciliation process in Australia, successful through thoughtful and respectful engagements, built around common human experiences and points of contact (the night sky). This Commentary briefly describes the collaboration, its outcomes, and future work.

This decade, the Square Kilometre Array (SKA) will perform its first observations. Preparations for building dishes, antennas, correlators and infrastructure are well underway. Concurrently, software for the processing of SKA observations is developed at a number of levels. At a more basic level there are the telescope monitoring and control systems and also the correlator software. On top of that, in order to deliver science ready data products, software pipelines are needed for radio frequency interference (RFI) mitigation, averaging, calibration and imaging. Here, we focus on the SAGECal calibration package, in particular on the times needed to obtain calibration solutions. This is an important aspect, since this package is now used for the Epoch of Reionization (EoR) Key Science Project of LOFAR, but will also have to run optimally on SKAI LOW. In terms of number of stations used for observing this amounts to a factor 10 increase, from 51 to 512 stations. Consequentially, the disk space needed to store an observation will increase by a factor 100, provided the number of frequency channels remains the same. In this paper we investigate the scaling behaviour of SAGECal, whose runtimes should ideally scale linearly with the number of stations. We also explain the algorithms inside SAGECal and use them to explain its scaling behaviour.

Modern radio telescopes will generate, on a daily basis, data sets on the scale of exabytes for systems like the Square Kilometre Array (SKA). Massive data sets are a source of unknown and rare astrophysical phenomena that lead to discoveries. Nonetheless, this is only plausible with the exploitation of machine learning to complement human-aided and traditional statistical techniques. Recently, there has been a surge in scientific publications focusing on the use of machine/deep learning in radio astronomy, addressing challenges such as source extraction, morphological classification, and anomaly detection. This study provides a comprehensive and concise overview of the use of machine learning techniques for the morphological classification of radio galaxies. It summarizes the recent literature on this topic, highlighting the main challenges, achievements, state-of-the-art methods, and the future research directions in the field. The application of machine learning in radio astronomy has led to a new paradigm shift and a revolution in the automation of complex data processes. However, the optimal exploitation of machine/deep learning in radio astronomy, calls for continued collaborative efforts in the creation of high-resolution annotated data sets. This is especially true in the case of modern telescopes like MeerKAT and the LOw-Frequency ARray (LOFAR). Additionally, it is important to consider the potential benefits of utilizing multi-channel data cubes and algorithms that can leverage massive datasets without relying solely on annotated datasets for radio galaxy classification.

ABSTRACTInnovation and skills development require interactive capabilities to function effectively. Interactive capabilities mediate between skills supply and skills demand actors in an innovation system, and in the knowledge economy more broadly. This article investigates such interactive capabilities, and the manner in which they facilitate labour market alignment. Within a case-study focus on the Square Kilometre Array (SKA) telescope in South Africa, we investigate how organisational capabilities, structures, and mechanisms facilitate or constrain interaction between the SKA and its network partners, including universities, firms, intermediaries, and a technical college. This illustrates how pockets of excellence within an unequal South African skills and innovation landscape were effectively connected in order to build a critical mass of skills and technologies that were highly competitive on the international stage. This shows how, in highly unequal developing countries, interactive capabilities form a lever for access to the global science and technology frontier.

Fast radio bursts (FRBs) are mysterious extragalactic radio signals. Revealing their origin is one of the central foci in modern astronomy. Previous studies suggest that occurrence rates of non-repeating and repeating FRBs could be controlled by the cosmic stellar-mass density (CSMD) and cosmic star formation-rate density (CSFRD), respectively. The Square Kilometre Array (SKA) is one of the best future instruments to address this subject due to its high sensitivity and high-angular resolution. Here, we predict the number of FRBs to be detected with the SKA. In contrast to previous predictions, we estimate the detections of non-repeating and repeating FRBs separately, based on latest observational constraints on their physical properties including the spectral indices, FRB luminosity functions, and their redshift evolutions. We consider two cases of redshift evolution of FRB luminosity functions following either the CSMD or CSFRD. At $z$ ≳ 2, $z$ ≳ 6, and $z$ ≳ 10, non-repeating FRBs will be detected with the SKA at a rate of ∼104, ∼102, and ∼10 (sky−1 d−1), respectively, if their luminosity function follows the CSMD evolution. At $z$ ≳ 1, $z$ ≳ 2, and $z$ ≳ 4, sources of repeating FRBs will be detected at a rate of ∼103, ∼102, and ≲10 (sky−1 d−1), respectively, assuming that the redshift evolution of their luminosity function is scaled with the CSFRD. These numbers could change by about one order of magnitude depending on the assumptions on the CSMD and CSFRD. In all cases, abundant FRBs will be detected by the SKA, which will further constrain the luminosity functions and number density evolutions.

Data rates from the Square Kilometre Array will be huge, rivalling the sum total of current global internet traffic. This deluge of data prompts a demand for significant progress in techniques for signal processing, data analysis and time-series modelling of vast data sets. Developing novel, real-time, machine learning algorithms is paramount if the SKA project is to meet its science objectives [1]. As a case study in SKA data analysis, this paper outlines some intrinsic difficulties in the search for binary pulsars, briefly describes known techniques for binary pulsar detection and proposes new detection approaches. Our current focus is to model more accurately sources of non-Gaussian, non-stationary noise in a typical pulsar search. Any solution must be scalable, to satisfy the real-time requirement of the SKA pulsar surveys.