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Medientyp:
E-Artikel
Titel:
Efficient wide-field radio interferometry response
Beteiligte:
Arras, Philipp;
Reinecke, Martin;
Westermann, Rüdiger;
Enßlin, Torsten A.
Erschienen:
EDP Sciences, 2021
Erschienen in:Astronomy & Astrophysics
Sprache:
Nicht zu entscheiden
DOI:
10.1051/0004-6361/202039723
ISSN:
0004-6361;
1432-0746
Entstehung:
Anmerkungen:
Beschreibung:
<jats:p>Radio interferometers do not measure the sky brightness distribution directly, but measure a modified Fourier transform of it. Imaging algorithms therefore need a computational representation of the linear measurement operator and its adjoint, regardless of the specific chosen imaging algorithm. In this paper, we present a C++ implementation of the radio interferometric measurement operator for wide-field measurements that is based on so-called improved <jats:italic>w</jats:italic>-stacking. It can provide high accuracy (down to ≈10<jats:sup>−12</jats:sup>), is based on a new gridding kernel that allows smaller kernel support for given accuracy, dynamically chooses kernel, kernel support, and oversampling factor for maximum performance, uses piece-wise polynomial approximation for cheap evaluations of the gridding kernel, treats the visibilities in cache-friendly order, uses explicit vectorisation if available, and comes with a parallelisation scheme that scales well also in the adjoint direction (which is a problem for many previous implementations). The implementation has a small memory footprint in the sense that temporary internal data structures are much smaller than the respective input and output data, allowing in-memory processing of data sets that needed to be read from disk or distributed across several compute nodes before.</jats:p>