Square Kilometre Array

The signal processing firmware that has been developed for the Low Frequency Aperture Array component of the Square Kilometre Array (SKA) is described. The firmware is implemented on a dual FPGA board, that is capable of processing the streams from 16 dual polarization antennas. Data processing includes channelization of the sampled data for each antenna, correction for instrumental response and for geometric delays and formation of one or more beams by combining the aligned streams. The channelizer uses an oversampling polyphase filterbank architecture, allowing a frequency continuous processing of the input signal without discontinuities between spectral channels. Each board processes the streams from 16 antennas, as part of larger beamforming system, linked by standard Ethernet interconnections. These are envisaged to be 8192 of these signal processing platforms in the first phase of the SKA so particular attention has been devoted to ensure the design is low cost and low power.

In 2007, in order to facilitate the building and operations of the Square Kilometre Array (SKA), the Astronomy Geographic Advantage Act proclaimed a large 'astronomy reserve' in the central Upper Karoo, a roughly rhombic space covering some 120,000 square kilometres. As it happens, this geographic reserve coincides almost exactly with a region described by |Xam prisoners of the mid 19th century as |Xam-ka !au, their homeland. We show how archival records indicate that jXam descendants are still living in the space now reserved for astronomy and how the claims of the Kalahari communities represented in the South African San Council of having once lived in the area lack substance. We compare the |Xam and the SKA notions of landscape, describe the historic evolution from the one to the other and suggest that benefit for local communities can only be in the form of bottom-up discussions about the planning of future developments and the distribution of tangible benefits.

EMU is a wide-field radio continuum survey planned for the new Australian Square Kilometre Array Pathfinder (ASKAP) telescope. The primary goal of EMU is to make a deep (rms ~ 10 microJy/beam) radio continuum survey of the entire Southern Sky at 1.3 GHz, extending as far North as +30 degrees declination, with a resolution of 10 arcsec. EMU is expected to detect and catalogue about 70 million galaxies, including typical star-forming galaxies up to z~1, powerful starbursts to even greater redshifts, and AGNs to the edge of the visible Universe. It will undoubtedly discover new classes of object. This paper defines the science goals and parameters of the survey, and describes the development of techniques necessary to maximise the science return from EMU.

In the Square Kilometre Array (SKA) telescope [1], [2], the noise temperature of the first LNA must be reduced in order to reduce the necessary active area and the total system costs. Cooling the LNA locally would significantly decrease the noise figure but also the necessary power since not the whole system has to be cooled. For optimal thermal isolation, an LNA chip which only needs 6 bondwires has been chosen, 4 Ground and 2 signal wires. Biasing occurs on-chip. If the bondwires are 1.5mm long, the total heat conduction of the 6 bondwires is 31 mW, which is added to the power consumption of the LNA (30 mW). With a power of 61 mW to cool, the Peltier element can achieve a -T of 60K. With this system, a noise reduction of 30% has been measured with 0.5W of electrical power. For 15% noise reduction, only 35mW of electrical power was needed.

A recent development within the MeerKAT sub-project of the Square Kilometre Array radio telescope network was the placement of a network of three observation cameras in pursuit of two specific visibility objectives.  In this paper, we evaluate the effectiveness of the locations of MeerKAT observation camera network according to a novel multi-objective Geographic Information Systems-based facility location framework.  We find that the configuration chosen and implemented by the MeerKAT decision-makers is of very high quality, although we are able to uncover slightly superior alternative placement configurations.  A significant amount of time and effort could, however, have been saved in the process of choosing the appropriate camera sites had our solutions been available to the decision-makers.

EMU is a wide-field radio continuum survey planned for the new Australian Square Kilometre Array Pathfinder (ASKAP) telescope. The primary goal of EMU is to make a deep (rms~ 10 μJy/beam) radio continuum survey of the entire Southern sky at 1.3 GHz, extending as far North as+ 30 declination, with a resolution of 10 arcsec. EMU is expected to detect and catalogue about 70 million galaxies, including typical star-forming galaxies up to z~ 1, powerful starbursts to even greater redshifts, and active galactic nuclei to the edge of the ...

The signal processing firmware that has been developed for the Low Frequency Aperture Array component of the Square Kilometre Array (SKA) is described. The firmware is implemented on a dual FPGA board, that is capable of processing the streams from 16 dual polarization antennas. Data processing includes channelization of the sampled data for each antenna, correction for instrumental response and for geometric delays and formation of one or more beams by combining the aligned streams. The channelizer uses an oversampling polyphase filterbank architecture, allowing a frequency continuous processing of the input signal without discontinuities between spectral channels. Each board processes the streams from 16 antennas, as part of larger beamforming system, linked by standard Ethernet interconnections. These are envisaged to be 8192 of these signal processing platforms in the first phase of the SKA so particular attention has been devoted to ensure the design is low cost and low power.

The MeerKAT (64 x 13.5m dish radio interferometer) is South Africa's precursor instrument for the Square Kilometre Array (SKA), exploring dish design, instrumentation, and the characteristics of a Karoo desert site and is projected to be on sky in 2016. One of two top-priority, Key Projects is a single deep field, integrating for 5000 hours total with the aim to detect neutral atomic hydrogen through its 21 cm line emission out to redshift unity and beyond. This first truly deep HI survey will help constrain fueling models for galaxy assembly and evolution. It will measure the evolution of the cosmic neutral gas density and its distribution over galaxies over cosmic time, explore evolution of the gas in galaxies, measure the Tully-Fisher relation, measure OH maser counts, and address many more topics. Here we present the observing strategy and envisaged science case for this unique deep field, which encompasses the Chandra Deep Field-South (and the footprints of GOODS, GEMS and...

The PULSE@Parkes (PULsar Student Exploration online at Parkes) project has been designed to allow high school students to control the 64m Parkes radio telescope. The students analyze their observations of radio pulsars and share their results with students in other schools. The data they obtain are also used by professional astronomers to support ongoing mainstream science projects. PULSE@Parkes provides students with an opportunity to use an iconic Australian major national facility, experience a real observation session and interact with professional astronomers. The embedded education research program seeks to determine the true value of the observing experience and whether students engage with the extensive online project materials. This project is the first stage of a long-term plan to develop effective and stimulating education activities that utilize the wealth of data that will be produced by the Australian Square Kilometre Array Pathfinder telescope that will be completed e...

EMU is a wide-field radio continuum survey planned for the new Australian Square Kilometre Array Pathfinder (ASKAP) telescope. The primary goal of EMU is to make a deep (rms~ 10 μJy/beam) radio continuum survey of the entire Southern sky at 1.3 GHz, extending as far North as+ 30 declination, with a resolution of 10 arcsec. EMU is expected to detect and catalogue about 70 million galaxies, including typical star-forming galaxies up to z~ 1, powerful starbursts to even greater redshifts, and active galactic nuclei to the edge of the ...

EMU is a wide-field radio continuum survey planned for the new Australian Square Kilometre Array Pathfinder (ASKAP) telescope. The primary goal of EMU is to make a deep (rms ∼ 10 μJy/beam) radio continuum survey of the entire Southern sky at 1.3 GHz, extending as far North as +30° declination, with a resolution of 10 arcsec. EMU is expected to detect and catalogue about 70 million galaxies, including typical star-forming galaxies up to z ∼ 1, powerful starbursts to even greater redshifts, and active galactic nuclei to the edge of the visible Universe. It will undoubtedly discover new classes of object. This paper defines the science goals and parameters of the survey, and describes the development of techniques necessary to maximise the science return from EMU.

EMU is a wide-field radio continuum survey planned for the new Australian Square Kilometre Array Pathfinder (ASKAP) telescope. The primary goal of EMU is to make a deep (rms ~ 10 microJy/beam) radio continuum survey of the entire Southern Sky at 1.3 GHz, extending as far North as +30 degrees declination, with a resolution of 10 arcsec. EMU is expected to detect and catalogue about 70 million galaxies, including typical star-forming galaxies up to z~1, powerful starbursts to even greater redshifts, and AGNs to the edge of the visible Universe. It will undoubtedly discover new classes of object. This paper defines the science goals and parameters of the survey, and describes the development of techniques necessary to maximise the science return from EMU.

Low frequency radio waves, while challenging to observe, are a rich source of information about pulsars. The LOw Frequency ARray (LOFAR) is a new radio interferometer operating in the lowest 4 octaves of the ionospheric "radio window": 10-240MHz, that will greatly facilitate observing pulsars at low radio frequencies. Through the huge collecting area, long baselines, and flexible digital hardware, it is expected that LOFAR will revolutionize radio astronomy at the lowest frequencies visible from Earth. LOFAR is a next-generation radio telescope and a pathfinder to the Square Kilometre Array (SKA), in that it incorporates advanced multi-beaming techniques between thousands of individual elements. We discuss the motivation for low-frequency pulsar observations in general and the potential of LOFAR in addressing these science goals. We present LOFAR as it is designed to perform high-time-resolution observations of pulsars and other fast transients, and outline the various relevant observing modes and data reduction pipelines that are already or will soon be implemented to facilitate these observations. A number of results obtained from commissioning observations are presented to demonstrate the exciting potential of the telescope. This paper outlines the case for low frequency pulsar observations and is also intended to serve as a reference for upcoming pulsar/fast transient science papers with LOFAR.

Visualisation and analysis of terabyte-scale datacubes, as will be produced with the Australian Square Kilometre Array Pathfinder (ASKAP), will pose challenges for existing astronomy software and the work practices of astronomers. Focusing on the proposed outcomes of WALLABY (Wide field ASKAP L-Band Legacy All-Sky Blind Survey), and using lessons learnt from HIPASS (HI Parkes All Sky Survey), we identify issues that astronomers will face with WALLABY data cubes. We comment on potential research directions and possible solutions to these challenges.

The Molonglo radio telescope near Canberra, Australia, is an east-west array of two collinear cylindri- cal parabolic reflectors with a total length of 1.6 km. Its 18,000 m 2 collecting area is the largest of any radio tele- scope in the Southern Hemisphere. We will prototype on the telescope, technologies relevant to the next generation radio telescope, the square kilometre array (SKA). We plan to equip the telescope with new wide-band feeds, low-noise amplifiers, digital filterbanks and FX correlator, and demon- strate 300-1420 MHz continuous frequency coverage and multibeam mode operation. This will allow us to develop and test several new technologies and will provide a new capability for low-frequency radio astronomy in Australia, enabling exploration of the distant universe. This project has recently been awarded funding by the Australian Government's Major National Research Facili- ties (MNRF) program, the University of Sydney and the Australia Telescope National Facility...

EMU is a wide-field radio continuum survey planned for the new Australian Square Kilometre Array Pathfinder (ASKAP) telescope. The primary goal of EMU is to make a deep (rms~ 10 μJy/beam) radio continuum survey of the entire Southern sky at 1.3 GHz, extending as far North as+ 30 declination, with a resolution of 10 arcsec. EMU is expected to detect and catalogue about 70 million galaxies, including typical star-forming galaxies up to z~ 1, powerful starbursts to even greater redshifts, and active galactic nuclei to the edge of the ...

The Square Kilometre Array Radio Telescope is the next generation radio telescope. An international project is currently under way to design and build an instrument having an effective collecting area two orders of magnitude greater than that of any existing telescope. A number of separate studies are presently investigating how to design the Square Kilometre Array to best carry out the kinds of observations desired by the astronomical community. We present a summary of one of these studies, a workshop called The ‘Sub-microJansky Radio Sky’ held at the ATNF, Sydney, on 17 June 1998. This workshop addressed the nature of the radio sky at the very faint flux densities likely to be attainable by the Square Kilometre Array. In particular, each speaker investigated a separate population of radio sources and how the expected appearance of that population at such faint flux densities would dictate how to refine some of the design constraints for the Square Kilometre Array.

The globally endorsed Square Kilometre Array project primarily aims to advance high sensitivity radio astronomy using a distributed collection of radio telescope stations spiraling outward from the core along three to five arms out to 3000km. This planned highly sensitive instrument covering a frequency range from 70MHz up to 10GHz will be used as wideband, high resolution, wide observing field

The Square Kilometre Array when completed will be the largest radio telescope in the world. The core of the African part of the array will be located in South Africa in the Karoo Desert. The town closest to the core is Carnarvon, the capitol of the Kareeberg Municipality. SKA ≥ Karoo Radio Telescope is a documentary film that captures the hopes and dreams of the people living near the SKA core and a variety of SKA stakeholders. The film is an experimental form of research ethnography centered around a set of hypotheses that were tested through the interviews conducted for the documentary. For example, one of the hypotheses was that the long term beneficiaries of the SKA will be the astronomers regardless of their proximity to Carnarvon, and that those beneficiaries would have very weak to non–existent ties to Carnarvon or that region of the Karoo Desert. Another hypothesis was that the people of Carnarvon would not have a clear understanding of the nature of astronomy development projects in contrast to traditional development projects. Transcripts from film clips are used to illustrate the 'answers' to these hypotheses and other tensions surrounding the SKA. Finally, the title tries to capture the pride and sense of ownership that people in the region and South Africa have towards the SKA, but it is much more than a regional or national telescope.

Traditional analysis techniques may not be sufficient for astronomers to make the best use of the data sets that current and future instruments, such as the Square Kilometre Array and its Pathfinders, will produce. By utilizing the incredible pattern-recognition ability of the human mind, scientific visualization provides an excellent opportunity for astronomers to gain valuable new insight and understanding of their data, particularly when used interactively in 3D. The goal of our work is to establish the feasibility of a real-time 3D monitoring system for data going into the Australian SKA Pathfinder archive. Based on CUDA, an increasingly popular development tool, our work utilizes the massively parallel architecture of modern graphics processing units (GPUs) to provide astronomers with an interactive 3D volume rendering for multi-spectral data sets. Unlike other approaches, we are targeting real time interactive visualization of datasets larger than GPU memory while giving special attention to data with low signal to noise ratio - two critical aspects for astronomy that are missing from most existing scientific visualization software packages. Our framework enables the astronomer to interact with the geometrical representation of the data, and to control the volume rendering process to generate a better representation of their datasets.