Efficient correction for both direction-dependent and baseline-dependent effects in interferometric imaging: An A-stacking framework

© 2015 ESO. 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 depen...

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Bibliographic Details
Main Authors: Young, A., Wijnholds, S., Carozzi, T., Maaskant, R., Ivashina, M., Davidson, David
Format: Journal Article
Published: EDP Sciences 2015
Online Access:http://hdl.handle.net/20.500.11937/71936
Description
Summary:© 2015 ESO. 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 ofa 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.