w-Stacking w-projection hybrid algorithm for wide-field interferometric imaging: implementation details and improvements

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 deploy the algorithm efficiently on a supercomputer via use of...

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Bibliographic Details
Published in:Publications of the Astronomical Society of Australia 2020, Vol.37, Article e041
Main Authors: Pratley, Luke, Johnston-Hollitt, Melanie, McEwen, Jason D.
Format: Article
Language:English
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Summary: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 deploy the algorithm efficiently on a supercomputer via use of a Message Passing Interface (MPI) k-means clustering technique to achieve efficient construction and application of non-coplanar effects. Additionally, we show that the use of conjugate symmetry can increase the w-stacking efficiency, decrease the time required to construction, and apply w-projection kernels for large data sets. We then demonstrate this implementation by imaging an interferometric observation of Fornax A from the Murchison Widefield Array (MWA). We perform an exact non-coplanar wide-field correction for 126.6 million visibilities using 50 nodes of a computing cluster. The w-projection kernel construction takes only 15 min prior to reconstruction, demonstrating that the implementation is both fast and efficient.
ISSN:1323-3580
1448-6083
DOI:10.1017/pasa.2020.28