Faceting for direction-dependent spectral deconvolution

C. Tasse, B. Hugo, M. Mirmont, O. Smirnov, M. Atemkeng, L. Bester, E. Bonnassieux, M. J. Hardcastle, R. Lakhoo, J.H.V. Girard, S. Makhathini, S. Perkins, Timothy W. Shimwell

Research output: Contribution to journalArticlepeer-review

72 Citations (Scopus)
71 Downloads (Pure)

Abstract

The new generation of radio interferometers is characterized by high sensitivity, wide fields of view and large fractional bandwidth. To synthesize the deepest images enabled by the high dynamic range of these instruments requires us to take into account the direction-dependent Jones matrices, while estimating the spectral properties of the sky in the imaging and deconvolution algorithms. In this paper we discuss and implement a wideband wide-field spectral deconvolution framework (ddfacet) based on image plane faceting, that takes into account generic direction-dependent effects. Specifically, we present a wide-field co-planar faceting scheme, and discuss the various effects that need to be taken into account to solve for the deconvolution problem (image plane normalization, position-dependent Point Spread Function, etc). We discuss two wideband spectral deconvolution algorithms based on hybrid matching pursuit and sub-space optimisation respectively. A few interesting technical features incorporated in our imager are discussed, including baseline dependent averaging, which has the effect of improving computing efficiency. The version of ddfacet presented here can account for any externally defined Jones matrices and/or beam patterns.

Original languageEnglish
Article numberA87
JournalAstronomy & Astrophysics
Volume611
DOIs
Publication statusPublished - 1 Mar 2018

Keywords

  • Instrumentation: adaptive optics
  • Instrumentation: interferometers
  • Methods: data analysis
  • Techniques: interferometric

Fingerprint

Dive into the research topics of 'Faceting for direction-dependent spectral deconvolution'. Together they form a unique fingerprint.

Cite this