The Engineering Development Array: A low frequency radio telescope utilising SKA precursor technology
Randall Wayth, Marcin Sokolowski, Tom Booler, Brian Crosse, David Emrich, Robert Grootjans, Peter J. Hall, Luke Horsley, Budi Juswardy, David Kenney, Kim Steele… 展开作者
Randall Wayth, Marcin Sokolowski, Tom Booler, Brian Crosse, David Emrich, Robert Grootjans, Peter J. Hall, Luke Horsley, Budi Juswardy, David Kenney, Kim Steele, Adrian Sutinjo, Steven J. Tingay, Daniel Ung, Mia Walker, Andrew Williams, A. Beardsley, T. M. O. Franzen, M. Johnston-Hollitt, D. L. Kaplan, M. F. Morales, D. Pallot, C. M. Trott, C. Wu
备注：
9 figs, 2 tables. Accepted for publication in PASA
We describe the design and performance of the Engineering Development Array (EDA), which is a low frequency radio telescope comprising 256 dual-polarisation dipole antennas working as a phased-array. The EDA was conceived of, developed, and deployed in just 18 months via re-use of Square Kilometre Array (SKA) precursor technology and expertise, specifically from the Murchison Widefield Array (MWA) radio telescope. Using drift scans and a model for the sky brightness temperature at low frequencies, we have derived the EDA's receiver temperature as a function of frequency. The EDA is shown to be sky-noise limited over most of the frequency range measured between 60 and 240 MHz. By using the EDA in interferometric mode with the MWA, we used calibrated visibilities to measure the absolute sensitivity of the array. The measured array sensitivity matches very well with a model based on the array layout and measured receiver temperature. The results demonstrate the practicality and feasibility of using MWA-style precursor technology for SKA-scale stations. The modular architecture of the EDA allows upgrades to the array to be rolled out in a staged approach. Future improvements to the EDA include replacing the second stage beamformer with a fully digital system, and to transition to using RF-over-fibre for the signal output from first stage beamformers.
New developments in data processing and visualization are being made in preparation for upcoming radioastronomical surveys planned with the Square Kilometre Array (SKA) and its precursors. A major goal is enabling extraction of science information from the data in a mostly automated way, possibly exploiting the capabilities offered by modern computing infrastructures and technologies. In this context, the integration of source analysis algorithms into data visualization tools is expected to significantly improve and speed up the cataloguing process of large area surveys. To this aim, the CIRAS…
Accurate instrumental bandpass corrections are essential for the reliable interpretation of spectral lines from targeted and survey-mode observations with radio interferometers. Bandpass correction is typically performed by comparing measurements of a strong calibrator source to an assumed model, typically an isolated point source. The wide field-of-view and high sensitivity of modern interferometers means that additional sources are often detected in observations of calibrators. This can introduce errors into bandpass corrections and subsequently the target data if not properly accounted for.…
Magnetic field couples the solar interior to the solar atmosphere, known as the corona. The coronal magnetic field is one of the crucial parameters which determines the coronal structures and regulates the space weather phenomena like flares, coronal mass ejections, energetic particle events, and solar winds. Measuring the magnetic field at middle and higher coronal heights are extremely difficult problem and to date there is no single measurement technique available to measure the higher coronal magnetic fields routinely. polarization measurements of the low-frequency radio emissions are an i…
The Widefield ASKAP L-band Legacy All-sky Blind surveY (WALLABY) is a neutral hydrogen survey (HI) that is running on the Australian SKA Pathfinder (ASKAP), a precursor telescope for the Square Kilometre Array (SKA). The goal of WALLABY is to use ASKAP's powerful wide-field phased array feed technology to observe three quarters of the entire sky at the 21 cm neutral hydrogen line with an angular resolution of 30 arcseconds. Post-processing activities at the Australian SKA Regional Centre (AusSRC), Canadian Initiative for Radio Astronomy Data Analysis (CIRADA) and Spanish SKA Regional Centre pr…
Solar, Heliospheric and Ionospheric Physics: Pathfinders, Precursors and SKAO Perspective
ASTRON - Netherlands Institute for Radio Astronomy（荷兰射电天文研究所）；Indian Institute of Technology, Kanpur（坎普尔印度理工学院）；National Centre for Radio Astrophysics, Tata Institute of Fundamental Research（塔塔基础研究院国家射电天体物理中心）；Dublin Institute for Advanced Studies（都柏林高等研究院）；University of Oslo（奥斯陆大学）；University of Bath（巴斯大学）
Backed by advances in digital electronics, signal processing, computation, and storage technologies, aperture arrays, which had strongly influenced the design of telescopes in the early years of radio astronomy, have made a comeback. Amid all these developments, an international effort to design and build the world's largest radio telescope, the Square Kilometre Array (SKA), is ongoing. With its vast collecting area of 1 sq-km, the SKA is envisaged to provide unsurpassed sensitivity and leverage technological advances to implement a complex receiver to provide a large field of view through mul…
Detection of intended and unintended emissions from Starlink satellites in the SKA-Low frequency range, at the SKA-Low site, with an SKA-Low station analog
The Square Kilometre Array (SKA) project consists of delivering two largest radio telescope arrays being built by the SKA Observatory (SKAO), which is an intergovernmental organization bringing together nations from around the world with China being one of the major member countries. The computing resources needed to process, distribute, curate and use the vast amount of data that will be generated by the SKA telescopes are too large for the SKAO to manage on its own. To address this challenge, the SKAO is working with the international community to create a shared, distributed data, computing…
The dynamics and the structure of the solar corona are determined by its magnetic field. Measuring coronal magnetic fields is, however, extremely hard. The polarization of low-frequency radio emissions has long been recognized as one of the few effective observational probes of magnetic fields in the mid and high corona. However, the extreme intrinsic variability of this emission, the limited ability of most of the available existing instrumentation (until recently) to capture it, and the technical challenges involved have all contributed to its use being severely limited. The high dynamic-ran…
Coronal magnetic fields are well known to be one of the crucial parameters defining coronal physics and space weather. However, measuring the global coronal magnetic fields remains challenging. The polarization properties of coronal radio emissions are sensitive to coronal magnetic fields. While they can prove to be useful probes of coronal and heliospheric magnetic fields, their usage has been limited by technical and algorithmic challenges. We present a robust algorithm for precise polarization calibration and imaging of low-radio frequency solar observations and demonstrate it on data from …
Accelerating radio astronomy imaging with RICK: a step towards SKA-Mid and SKA-Low
INAF-Osservatorio astronomico di Brera（意大利国家天体物理研究所布雷拉天文台）；ICSC – Centro Nazionale di Ricerca in High Performance Computing, Big Data e Quantum Computing（高性能计算、大数据与量子计算国家研究中心）；Dipartimento di Fisica e Astronomia, Università di Bologna（博洛尼亚大学物理与天文学系）；Istituto di Radioastronomia, INAF（意大利国家天体物理研究所射电天文研究所）；INAF-Osservatorio Astronomico di Trieste（意大利国家天体物理研究所的里雅斯特天文台）
RICK 2.0 利用 HeFFTe 库实现高效分布式快速傅里叶变换，提升射电成像性能，适用于 SKA-Mid 和 SKA-Low 项目。
The Square Kilometre Array (SKA) will answer fundamental questions about the origin, evolution, properties, and influence of magnetic fields throughout the Universe. Magnetic fields can illuminate and influence phenomena as diverse as star formation, galactic dynamics, fast radio bursts, active galactic nuclei, large-scale structure, and Dark Matter annihilation. Preparations for the SKA are swiftly continuing worldwide, and the community is making tremendous observational progress in the field of cosmic magnetism using data from a powerful international suite of SKA pathfinder and precursor t…
YOLO-CIANNA: Galaxy detection with deep learning in radio data: II. Winning the SKA SDC2 using a generalized 3D-YOLO network
LUX, Observatoire de Paris, Université PSL, Sorbonne Université, CNRS（巴黎天文台卢克斯实验室，巴黎文理研究大学，索邦大学，法国国家科学研究中心）；Canadian Institute for Theoretical Astrophysics, University of Toronto（加拿大理论天体物理研究所，多伦多大学）；Research School of Astronomy & Astrophysics, Australian National University（澳大利亚国立大学天文与天体物理研究学院）；Université de Strasbourg, CNRS UMR 7550, Observatoire astronomique de Strasbourg（斯特拉斯堡大学，法国国家科学研究中心UMR 7550，斯特拉斯堡天文台）；DIO, Observatoire de Paris, CNRS, PSL（巴黎天文台数据与信息办公室，法国国家科学研究中心，巴黎文理研究大学）；IDRIS, CNRS（法国国家科学研究中心集成系统研究所）；Collège de France（法兰西公学院）；Department of Physics & Electronics, Rhodes University（罗兹大学物理与电子系）
Imaging the low-frequency radio Sun is an intrinsically challenging problem. Meter-wavelength solar emission spans angular scales from a few arcminutes to a few degrees. These emissions show temporal and spectral variability on a sub-second and sub-MHz scales. The brightness temperature of these emissions also varies by many orders of magnitude, which requires high-dynamic-range spectroscopic snapshot imaging. With the unique array configuration of the Murchison Widefield Array (MWA), and the robust calibration and imaging pipeline, Automated Imaging Routine for the Compact Arrays for the Radi…
With SKA precursor and pathfinder operations in full swing, radio and (sub-)mm astronomy is entering the era of super big data. The big questions is how to make (sub-)mm and radio data available to the astronomical community, preferably using FAIR (findable, accessible, interoperable and re-useable; Wilkinson et al. 2016) principles. There are already a lot of efforts going on around the globe: facilities such as ALMA, LOFAR, MWA, NRAO and ASKAP are already publishing much of their imaging data in the form of "science ready" products, SKA regional centres are being formed and a radio astronomy…
This paper presents a framework to compute the receiver noise temperature (Trcv) of two low-frequency radio telescopes, the Murchison Widefield Array (MWA) and the Engineering Development Array (EDA). The MWA was selected because it is the only operational low-frequency Square Kilometre Array (SKA) precursor at the Murchison Radio-astronomy Observatory, while the EDA was selected because it mimics the proposed SKA-Low station size and configuration. It will demonstrated that the use of an existing power wave based framework for noise characterization of multiport amplifiers is sufficiently gen…
Source finding is one of the most challenging tasks in upcoming radio continuum surveys with SKA precursors, such as the Evolutionary Map of the Universe (EMU) survey of the Australian SKA Pathfinder (ASKAP) telescope. The resolution, sensitivity, and sky coverage of such surveys is unprecedented, requiring new features and improvements to be made in existing source finders. Among them, reducing the false detection rate, particularly in the Galactic plane, and the ability to associate multiple disjoint islands into physical objects. To bridge this gap, we developed a new source finder, based o…
One of the major priorities of international radio astronomy is to study the early universe through the detection of the 21 cm HI line from the epoch of reionisation (EoR). Due to the weak nature of the 21 cm signal, an important part in the detection of the EoR is removing contaminating foregrounds from our observations as they are multiple orders of magnitude brighter. In order to achieve this, sky maps spanning a wide range of frequencies and angular scales are required for calibration and foreground subtraction. Complementing the existing low-frequency sky maps, we have constructed a South…
STORMY : A Real-time Triggering Framework using Yamagawa Solar Spectrograph for Active Solar Emission Observations with the MWA
National Centre for Radio Astrophysics, Tata Institute of Fundamental Research（国家射电天文中心，塔塔基础研究所）；University Corporation for Atmospheric Research（大气研究大学联盟）；National Institute of Information and Communications Technology（信息通信技术研究机构）；Curtin University（科廷大学）；International Centre for Radio Astronomy Research（国际射电天文研究中心）
The LOw-Frequency ARray is a low-frequency radio interferometer composed by observational stations spread across Europe and it is the largest precursor of SKA in terms of effective area and generated data rates. In 2018, the Italian community officially joined LOFAR project, and it deployed a distributed computing and storage infrastructure dedicated to LOFAR data analysis. The infrastructure is based on 4 nodes distributed in different Italian locations and it offers services for pipelines execution, storage of final and intermediate results and support for the use of the software and infrast…
The Murchison Widefield Array Phase III upgrade: Sensitivity Doubled, Number of Baselines Quadrupled, Flexibility Enhanced, and EoR Observations Optimised
International Centre for Radio Astronomy Research, Curtin University（国际射电天文研究中心，科廷大学）；Curtin Institute for Data Science, Curtin University（科廷数据科学研究所，科廷大学）；SKA Observatory（平方公里阵列巡天望远镜观测站）；Centre of Excellence for All Sky Astrophysics in 3 Dimensions (ASTRO 3D)（三维全天空天体物理学卓越中心 (ASTRO 3D)）
