dc.contributor.author Mort, B en dc.contributor.author Dulwich, F en dc.contributor.author Razavi-Ghods, Nima en dc.contributor.author Acedo, EDL en dc.contributor.author Grainge, K en dc.date.accessioned 2017-03-06T10:17:22Z dc.date.available 2017-03-06T10:17:22Z dc.date.issued 2017-03 en dc.identifier.issn 0035-8711 dc.identifier.uri https://www.repository.cam.ac.uk/handle/1810/262875 dc.description.abstract The Square Kilometre Array’s Low Frequency instrument (SKA-LOW) will operate in the undersampled regime for most of the frequency band where grating lobes pose particular challenges. To achieve the expected level of sensitivity for SKA-LOW, it is particularly important to understand how interfering sources in both near and far side-lobes of the station beam affect the imaging performance. In this study, we discuss options for station designs, and adopting a random element layout, we assess its effectiveness by investigating how sources far from the main lobe of the station beam degrade images of the target field. These sources have the effect of introducing a noise-like corruption to images, which is called the far sidelobe confusion noise (FSCN). Using $\tiny{OSKAR}$, a software simulator accelerated using graphics processing units, we carried out end-to-end simulations using an all-sky model and telescope configuration representative of the SKA-LOW instrument. The FSCN is a function of both the station beam and the interferometric point spread function, and decreases with increasing observation time until the coverage of the aperture plane no longer improves. Using apodization to reduce the level of near-in sidelobes of the station beam had a notable improvement on the level of the FSCN at low frequencies. Our results indicate that the effects of picking up sources in the sidelobes are worse at low frequencies, where the array is less sparse. dc.description.sponsorship This work used the Wilkes GPU cluster at the University of Cambridge High Performance Computing Service (http://www.hpc.cam.ac.uk/), provided by Dell Inc., NVIDIA and Mellanox, and part funded by STFC with industrial sponsorship from Rolls Royce and Mitsubishi Heavy Industries. dc.language.iso en en dc.publisher Oxford University Press dc.subject instrumentation: interferometers en dc.subject techniques: interferometric en dc.subject telescopes en dc.title Analysing the impact of far-out sidelobes on the imaging performance of the SKA-LOW telescope en dc.type Article prism.endingPage 3692 prism.issueIdentifier 3 en prism.publicationDate 2017 en prism.publicationName Monthly Notices of the Royal Astronomical Society en prism.startingPage 3680 prism.volume 465 en dc.identifier.doi 10.17863/CAM.8166 dcterms.dateAccepted 2016-10-31 en rioxxterms.versionofrecord 10.1093/mnras/stw2814 en rioxxterms.version VoR en rioxxterms.licenseref.uri http://www.rioxx.net/licenses/all-rights-reserved en rioxxterms.licenseref.startdate 2017-03 en dc.contributor.orcid Razavi-Ghods, Nima [0000-0003-2930-5396] dc.identifier.eissn 1365-2966 dc.publisher.url http://dx.doi.org/10.1093/mnras/stw2814 en rioxxterms.type Journal Article/Review en pubs.funder-project-id STFC (ST/M001393/1) cam.issuedOnline 2016-11-03 en dc.identifier.url http://dx.doi.org/10.1093/mnras/stw2814 en cam.orpheus.success Thu Jan 30 12:56:44 GMT 2020 - The item has an open VoR version. * rioxxterms.freetoread.startdate 2100-01-01
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