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Related papers: Wide field imaging for the Square Kilometre Array

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The Square Kilometre Array (SKA) is the largest radio interferometer under construction in the world. The high accuracy, wide-field and large size imaging significantly challenge the construction of the Science Data Processor (SDP) of SKA.…

Instrumentation and Methods for Astrophysics · Physics 2022-07-20 Yangfan Xie , Feng Wang , Hui Deng , Ying Mei , Ying-He Celeste Lu , Gabriella Hodosan , Vladislav Stolyarov , Oleg Smirnov , Xiaofeng Li , Tim Cornwell

We consider a troublesome form of non-isoplanatism in synthesis radio telescopes: non-coplanar baselines. We present a novel interpretation of the non-coplanar baselines effect as being due to differential Fresnel diffraction in the…

Astrophysics · Physics 2009-11-13 T. J. Cornwell , K. Golap , S. Bhatnagar

We present a detailed discussion of the implementation strategies for a recently developed $w$-stacking $w$-projection hybrid algorithm used to reconstruct wide-field interferometric images. In particular, we discuss the methodology used to…

Instrumentation and Methods for Astrophysics · Physics 2020-10-14 L. Pratley , M. Johnston-Hollitt , J. D. McEwen

With the development of modern radio interferometers, wide-field continuum surveys have been planned and undertaken, for which accurate wide-field imaging methods are essential. Based on the widely-used W-stacking method, we propose a new…

Instrumentation and Methods for Astrophysics · Physics 2023-05-01 Haoyang Ye , Steve F. Gull , Sze M. Tan , Bojan Nikolic

The standard wide-field imaging technique, the $w$-projection, allows correction for wide-fields of view for non-coplanar radio interferometric arrays. However, calculating exact corrections for each measurement has not been possible due to…

Instrumentation and Methods for Astrophysics · Physics 2019-04-10 Luke Pratley , Melanie Johnston-Hollitt , Jason D. McEwen

W projection is a commonly-used approach to allow interferometric imaging to be accelerated by Fast Fourier Transforms (FFTs), but it can require a huge amount of storage for convolution kernels. The kernels are not separable, but we show…

Instrumentation and Methods for Astrophysics · Physics 2016-01-27 Bruce Merry

This paper proposes a polyline shaped array based system scheme, associated with mechanical scanning along the perpendicular direction of the array, for near-field millimeter-wave (MMW) imaging. Each section of the polyline is a chord of a…

Signal Processing · Electrical Eng. & Systems 2021-09-08 Shuoguang Wang , Shiyong Li , Guoqiang Zhao , Houjun Sun

Next-generation radio interferometric telescopes will exhibit non-coplanar baseline configurations and wide field-of-views, inducing a w-modulation of the sky image, which in turn induces the spread spectrum effect. We revisit the impact of…

Instrumentation and Methods for Astrophysics · Physics 2013-11-27 L. Wolz , J. D. McEwen , F. B. Abdalla , R. E. Carrillo , Y. Wiaux

This paper describes the system architecture of a newly constructed radio telescope - the Boolardy Engineering Test Array, which is a prototype of the Australian Square Kilometre Array Pathfinder telescope. Phased array feed technology is…

Multiple-input multiple-output (MIMO) array based millimeter-wave (MMW) imaging has a tangible prospect in applications of concealed weapons detection. A near-field imaging algorithm based on wavenumber domain processing is proposed for a…

Signal Processing · Electrical Eng. & Systems 2021-01-25 Shiyong Li , Shuoguang Wang , Moeness G. Amin , Guoqiang Zhao

We present a new algorithm to perform wide-field radio interferometric image reconstruction, with exact non-coplanar correction, that scales to big-data. This algorithm allows us to image 2 billion visibilities on 50 nodes of a computing…

Instrumentation and Methods for Astrophysics · Physics 2019-03-20 Luke Pratley , Jason D. McEwen

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…

Solar and Stellar Astrophysics · Physics 2022-09-22 Devojyoti Kansabanik

Modern radio telescopes, such as the Square Kilometre Array (SKA), will probe the radio sky over large fields-of-view, which results in large w-modulations of the sky image. This effect complicates the relationship between the measured…

Instrumentation and Methods for Astrophysics · Physics 2017-07-14 Arwa Dabbech , Laura Wolz , Luke Pratley , Jason D. McEwen , Yves Wiaux

Incorporating wide-field considerations in interferometric imaging is of increasing importance for next-generation radio telescopes. Compressed sensing techniques for interferometric imaging have been extended to wide fields recently,…

Instrumentation and Methods for Astrophysics · Physics 2011-08-29 J. D. McEwen , Y. Wiaux

Since the 1970s, much of traditional interferometric imaging has been built around variations of the CLEAN algorithm, in both terminology, methodology, and algorithm development. Recent developments in applying new algorithms from convex…

Instrumentation and Methods for Astrophysics · Physics 2020-09-29 Luke Pratley , Melanie Johnston-Hollitt , Jason D. McEwen

Antenna layout is an important design consideration for radio interferometers because it determines the quality of the snapshot point spread function (PSF, or array beam). This is particularly true for experiments targeting the 21 cm Epoch…

The new generation of radio telescopes, such as the Square Kilometer Array (SKA), requires dramatic advances in computer hardware and software, in order to process the large amounts of produced data efficiently. In this document, we explore…

Instrumentation and Methods for Astrophysics · Physics 2015-04-15 Matthias Petschow

The Australia Telescope Compact Array and the Very Large Array are currently being upgraded to operate with wide bandwidths; interferometers dedicated to the measurement of cosmic microwave background anisotropies are being designed with…

Astrophysics · Physics 2009-11-10 Ravi Subrahmanyan

Radio interferometers do not measure the sky brightness distribution directly but rather a modified Fourier transform of it. Imaging algorithms, thus, need a computational representation of the linear measurement operator and its adjoint,…

Instrumentation and Methods for Astrophysics · Physics 2021-02-10 Philipp Arras , Martin Reinecke , Rüdiger Westermann , Torsten A. Enßlin
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