Wide field imaging for the square kilometre array
Abstract
Wide-field radio interferometric telescopes such as the Square Kilometre Array now being designed are subject to a number of aberrations. One particularly pernicious aberration is that due to non-coplanar baselines whereby long baselines incur a quadratic image-plane phase error. There are numerous algorithms for dealing with the non-coplanar baselines effect. As a result of our experience with developing processing software for the Australian Square Kilometre Array Pathinder, we advocate the use of a hybrid algorithm, called w snapshots, based on a combination of w projection and snapshot imaging. This hybrid overcomes some of the deficiencies of each and has advantages from both. Compared to pure w projection, w snapshots uses less memory and execution time, and compared to pure snapshot imaging, w snapshots uses less memory and is more accurate. At the asymptotes, w snapshots devolves to w projection and to snapshots.
- Publication:
-
Image Reconstruction from Incomplete Data VII
- Pub Date:
- October 2012
- DOI:
- 10.1117/12.929336
- arXiv:
- arXiv:1207.5861
- Bibcode:
- 2012SPIE.8500E..0LC
- Keywords:
-
- Astrophysics - Instrumentation and Methods for Astrophysics
- E-Print:
- To be presented at SPIE Optic and Photonics, Image Reconstruction from Incomplete Data VII, August 2012