w-Stacking w-projection hybrid algorithm for wide-field interferometric imaging: implementation details and improvements
Abstract
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.
- Publication:
-
Publications of the Astronomical Society of Australia
- Pub Date:
- October 2020
- DOI:
- 10.1017/pasa.2020.28
- arXiv:
- arXiv:1903.06555
- Bibcode:
- 2020PASA...37...41P
- Keywords:
-
- methods: data analysis;
- techniques: image processing;
- techniques: interferometric;
- Astrophysics - Instrumentation and Methods for Astrophysics
- E-Print:
- 10 Pages, 2 Figures. arXiv admin note: text overlap with arXiv:1807.09239