DIRECTION-DEPENDENT POLARIZED PRIMARY BEAMS IN WIDE-FIELD SYNTHESIS IMAGING
The process of wide-field synthesis imaging is explored, with the aim of understanding the implications of variable, polarised primary beams for forthcoming Epoch of Reionisation experiments. These experiments seek to detect weak signatures from redshifted 21cm emission in deep residual datasets, af...
| Main Authors: | , , , , |
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| Format: | Journal Article |
| Published: |
WORLD SCIENTIFIC PUBL CO PTE LTD
2012
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| Online Access: | http://hdl.handle.net/20.500.11937/58558 |
| _version_ | 1848760290004434944 |
|---|---|
| author | Mitchell, D. Wayth, Randall Bernardi, G. Greenhill, L. Ord, S. |
| author_facet | Mitchell, D. Wayth, Randall Bernardi, G. Greenhill, L. Ord, S. |
| author_sort | Mitchell, D. |
| building | Curtin Institutional Repository |
| collection | Online Access |
| description | The process of wide-field synthesis imaging is explored, with the aim of understanding the implications of variable, polarised primary beams for forthcoming Epoch of Reionisation experiments. These experiments seek to detect weak signatures from redshifted 21cm emission in deep residual datasets, after suppression and subtraction of foreground emission. Many subtraction algorithms benefit from low side-lobes and polarisation leakage at the outset, and both of these are intimately linked to how the polarised primary beams are handled. Building on previous contributions from a number of authors, in which direction-dependent corrections are incorporated into visibility gridding kernels, we consider the special characteristics of arrays of fixed dipole antennas operating around 100-200 MHz, looking towards instruments such as the Square Kilometre Array (SKA) and the Hydrogen Epoch of Reionization Arrays (HERA). We show that integrating snapshots in the image domain can help to produce compact gridding kernels, and also reduce the need to make complicated polarised leakage corrections during gridding. We also investigate an alternative form for the gridding kernel that can suppress variations in the direction-dependent weighting of gridded visibilities by 10s of dB, while maintaining compact support. |
| first_indexed | 2025-11-14T10:13:25Z |
| format | Journal Article |
| id | curtin-20.500.11937-58558 |
| institution | Curtin University Malaysia |
| institution_category | Local University |
| last_indexed | 2025-11-14T10:13:25Z |
| publishDate | 2012 |
| publisher | WORLD SCIENTIFIC PUBL CO PTE LTD |
| recordtype | eprints |
| repository_type | Digital Repository |
| spelling | curtin-20.500.11937-585582017-11-24T05:45:57Z DIRECTION-DEPENDENT POLARIZED PRIMARY BEAMS IN WIDE-FIELD SYNTHESIS IMAGING Mitchell, D. Wayth, Randall Bernardi, G. Greenhill, L. Ord, S. The process of wide-field synthesis imaging is explored, with the aim of understanding the implications of variable, polarised primary beams for forthcoming Epoch of Reionisation experiments. These experiments seek to detect weak signatures from redshifted 21cm emission in deep residual datasets, after suppression and subtraction of foreground emission. Many subtraction algorithms benefit from low side-lobes and polarisation leakage at the outset, and both of these are intimately linked to how the polarised primary beams are handled. Building on previous contributions from a number of authors, in which direction-dependent corrections are incorporated into visibility gridding kernels, we consider the special characteristics of arrays of fixed dipole antennas operating around 100-200 MHz, looking towards instruments such as the Square Kilometre Array (SKA) and the Hydrogen Epoch of Reionization Arrays (HERA). We show that integrating snapshots in the image domain can help to produce compact gridding kernels, and also reduce the need to make complicated polarised leakage corrections during gridding. We also investigate an alternative form for the gridding kernel that can suppress variations in the direction-dependent weighting of gridded visibilities by 10s of dB, while maintaining compact support. 2012 Journal Article http://hdl.handle.net/20.500.11937/58558 10.1142/S2251171712500031 WORLD SCIENTIFIC PUBL CO PTE LTD restricted |
| spellingShingle | Mitchell, D. Wayth, Randall Bernardi, G. Greenhill, L. Ord, S. DIRECTION-DEPENDENT POLARIZED PRIMARY BEAMS IN WIDE-FIELD SYNTHESIS IMAGING |
| title | DIRECTION-DEPENDENT POLARIZED PRIMARY BEAMS IN WIDE-FIELD SYNTHESIS IMAGING |
| title_full | DIRECTION-DEPENDENT POLARIZED PRIMARY BEAMS IN WIDE-FIELD SYNTHESIS IMAGING |
| title_fullStr | DIRECTION-DEPENDENT POLARIZED PRIMARY BEAMS IN WIDE-FIELD SYNTHESIS IMAGING |
| title_full_unstemmed | DIRECTION-DEPENDENT POLARIZED PRIMARY BEAMS IN WIDE-FIELD SYNTHESIS IMAGING |
| title_short | DIRECTION-DEPENDENT POLARIZED PRIMARY BEAMS IN WIDE-FIELD SYNTHESIS IMAGING |
| title_sort | direction-dependent polarized primary beams in wide-field synthesis imaging |
| url | http://hdl.handle.net/20.500.11937/58558 |