Issue |
A&A
Volume 577, May 2015
|
|
---|---|---|
Article Number | A56 | |
Number of page(s) | 11 | |
Section | Numerical methods and codes | |
DOI | https://doi.org/10.1051/0004-6361/201425492 | |
Published online | 01 May 2015 |
Efficient correction for both direction-dependent and baseline-dependent effects in interferometric imaging: An A-stacking framework
1
Department of Electrical and Electronic EngineeringStellenbosch
University,
7599
Stellenbosch,
South Africa
e-mail:
ayoung.at.sun@gmail.com
2
Netherlands Institute for Radio Astronomy (ASTRON),
7990AA
Dwingeloo, The
Netherlands
3
Department of Earth and Space Sciences, Chalmers University of
Technology, 412
58
Gothenburg,
Sweden
4
Department of Signals and Systems, Chalmers University of
Technology, 412
58
Gothenburg,
Sweden
Received: 10 December 2014
Accepted: 23 February 2015
A general framework is presented for modeling direction-dependent effects that are also baseline-dependent, as part of the calibration and imaging process. Within this framework such effects are represented as a parametric linear model in which basis functions account for direction dependence, whereas expansion coefficients account for the baseline dependence. This separation enables the use of a multiple fast Fourier transform-based implementation of the forward calculation (sky to visibility) in a manner similar to the W-stacking solution for non-coplanar baselines, and offers a potential improvement in computational efficiency in scenarios where the gridding operation in a convolution-based approach to direction-dependent effects may be too costly. Two novel imaging approaches that are possible within this framework are also presented.
Key words: methods: analytical / methods: numerical / techniques: image processing
© ESO, 2015
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