Self Direction-Dependent Calibration For Wideband Radio-Interferometric Imaging

Research output: Contribution to conferencePaper

Abstract

Radio-interferometric (RI) imaging can be formulated as
an inverse problem, where the objective is to estimate a sky intensity image from degraded undersampled Fourier measurements. Future radio telescopes aim at improving imaging resolution and sensitivity by orders of magnitude. At this precision level, the reconstruction quality will be limited by the unknown calibration kernels. Accurate calibration of the array during imaging is thus needed, leading to a blind deconvolution problem. Recently, we have proposed a non-convex optimisation method to perform joint calibration and imaging in the context of monochromatic imaging, assuming that the calibration kernels are smooth both in space and time. In the current work, we extend this approach to wideband imaging by further assuming spectral smoothness of the calibration kernels. The resulting problem is solved using an alternating forwardbackward scheme, benefiting from convergence guarantees.
Original languageEnglish
Number of pages1
Publication statusPublished - Feb 2019
EventInternational BASP Frontiers workshop 2019 - Villars sur Ollon, Switzerland
Duration: 3 Feb 20198 Feb 2019
http://www.baspfrontiers.org

Workshop

WorkshopInternational BASP Frontiers workshop 2019
CountrySwitzerland
CityVillars sur Ollon
Period3/02/198/02/19
Internet address

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radio telescopes
sky
broadband
optimization
sensitivity
estimates

Cite this

Dabbech, A., Repetti, A., & Wiaux, Y. (2019). Self Direction-Dependent Calibration For Wideband Radio-Interferometric Imaging. Paper presented at International BASP Frontiers workshop 2019, Villars sur Ollon, Switzerland.
Dabbech, Arwa ; Repetti, Audrey ; Wiaux, Yves. / Self Direction-Dependent Calibration For Wideband Radio-Interferometric Imaging. Paper presented at International BASP Frontiers workshop 2019, Villars sur Ollon, Switzerland.1 p.
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title = "Self Direction-Dependent Calibration For Wideband Radio-Interferometric Imaging",
abstract = "Radio-interferometric (RI) imaging can be formulated asan inverse problem, where the objective is to estimate a sky intensity image from degraded undersampled Fourier measurements. Future radio telescopes aim at improving imaging resolution and sensitivity by orders of magnitude. At this precision level, the reconstruction quality will be limited by the unknown calibration kernels. Accurate calibration of the array during imaging is thus needed, leading to a blind deconvolution problem. Recently, we have proposed a non-convex optimisation method to perform joint calibration and imaging in the context of monochromatic imaging, assuming that the calibration kernels are smooth both in space and time. In the current work, we extend this approach to wideband imaging by further assuming spectral smoothness of the calibration kernels. The resulting problem is solved using an alternating forwardbackward scheme, benefiting from convergence guarantees.",
author = "Arwa Dabbech and Audrey Repetti and Yves Wiaux",
year = "2019",
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Dabbech, A, Repetti, A & Wiaux, Y 2019, 'Self Direction-Dependent Calibration For Wideband Radio-Interferometric Imaging' Paper presented at International BASP Frontiers workshop 2019, Villars sur Ollon, Switzerland, 3/02/19 - 8/02/19, .

Self Direction-Dependent Calibration For Wideband Radio-Interferometric Imaging. / Dabbech, Arwa; Repetti, Audrey; Wiaux, Yves.

2019. Paper presented at International BASP Frontiers workshop 2019, Villars sur Ollon, Switzerland.

Research output: Contribution to conferencePaper

TY - CONF

T1 - Self Direction-Dependent Calibration For Wideband Radio-Interferometric Imaging

AU - Dabbech, Arwa

AU - Repetti, Audrey

AU - Wiaux, Yves

PY - 2019/2

Y1 - 2019/2

N2 - Radio-interferometric (RI) imaging can be formulated asan inverse problem, where the objective is to estimate a sky intensity image from degraded undersampled Fourier measurements. Future radio telescopes aim at improving imaging resolution and sensitivity by orders of magnitude. At this precision level, the reconstruction quality will be limited by the unknown calibration kernels. Accurate calibration of the array during imaging is thus needed, leading to a blind deconvolution problem. Recently, we have proposed a non-convex optimisation method to perform joint calibration and imaging in the context of monochromatic imaging, assuming that the calibration kernels are smooth both in space and time. In the current work, we extend this approach to wideband imaging by further assuming spectral smoothness of the calibration kernels. The resulting problem is solved using an alternating forwardbackward scheme, benefiting from convergence guarantees.

AB - Radio-interferometric (RI) imaging can be formulated asan inverse problem, where the objective is to estimate a sky intensity image from degraded undersampled Fourier measurements. Future radio telescopes aim at improving imaging resolution and sensitivity by orders of magnitude. At this precision level, the reconstruction quality will be limited by the unknown calibration kernels. Accurate calibration of the array during imaging is thus needed, leading to a blind deconvolution problem. Recently, we have proposed a non-convex optimisation method to perform joint calibration and imaging in the context of monochromatic imaging, assuming that the calibration kernels are smooth both in space and time. In the current work, we extend this approach to wideband imaging by further assuming spectral smoothness of the calibration kernels. The resulting problem is solved using an alternating forwardbackward scheme, benefiting from convergence guarantees.

M3 - Paper

ER -

Dabbech A, Repetti A, Wiaux Y. Self Direction-Dependent Calibration For Wideband Radio-Interferometric Imaging. 2019. Paper presented at International BASP Frontiers workshop 2019, Villars sur Ollon, Switzerland.