Lofar Facet Calibration

LOFAR, the Low-Frequency Array, is a powerful new radio telescope operating between 10 and 240 MHz. LOFAR allows detailed sensitive high-resolution studies of the low-frequency radio sky. At the same time LOFAR also provides excellent short baseline coverage to map diffuse extended emission. However...

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Main Authors: Weeren, R., Williams, W., Hardcastle, M., Shimwell, T., Rafferty, D., Sabater, J., Heald, G., Sridhar, S., Dijkema, T., Brunetti, G., Brüggen, M., Andrade-Santos, F., Ogrean, G., Röttgering, H., Dawson, W., Forman, W., Gasperin, F., Jones, C., Miley, G., Rudnick, L., Sarazin, C., Bonafede, A., Best, P., Birzan, L., Cassano, R., Chyzy, K., Croston, J., Ensslin, T., Ferrari, C., Hoeft, M., Horellou, C., Jarvis, M., Kraft, R., Mevius, M., Intema, Hubertus, Murray, S., Orrú, E., Pizzo, R., Simionescu, A., Stroe, A., Tol, S., White, G.
Format: Journal Article
Published: Institute of Physics Publishing 2016
Online Access:http://hdl.handle.net/20.500.11937/74204
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author Weeren, R.
Williams, W.
Hardcastle, M.
Shimwell, T.
Rafferty, D.
Sabater, J.
Heald, G.
Sridhar, S.
Dijkema, T.
Brunetti, G.
Brüggen, M.
Andrade-Santos, F.
Ogrean, G.
Röttgering, H.
Dawson, W.
Forman, W.
Gasperin, F.
Jones, C.
Miley, G.
Rudnick, L.
Sarazin, C.
Bonafede, A.
Best, P.
Birzan, L.
Cassano, R.
Chyzy, K.
Croston, J.
Ensslin, T.
Ferrari, C.
Hoeft, M.
Horellou, C.
Jarvis, M.
Kraft, R.
Mevius, M.
Intema, Hubertus
Murray, S.
Orrú, E.
Pizzo, R.
Simionescu, A.
Stroe, A.
Tol, S.
White, G.
author_facet Weeren, R.
Williams, W.
Hardcastle, M.
Shimwell, T.
Rafferty, D.
Sabater, J.
Heald, G.
Sridhar, S.
Dijkema, T.
Brunetti, G.
Brüggen, M.
Andrade-Santos, F.
Ogrean, G.
Röttgering, H.
Dawson, W.
Forman, W.
Gasperin, F.
Jones, C.
Miley, G.
Rudnick, L.
Sarazin, C.
Bonafede, A.
Best, P.
Birzan, L.
Cassano, R.
Chyzy, K.
Croston, J.
Ensslin, T.
Ferrari, C.
Hoeft, M.
Horellou, C.
Jarvis, M.
Kraft, R.
Mevius, M.
Intema, Hubertus
Murray, S.
Orrú, E.
Pizzo, R.
Simionescu, A.
Stroe, A.
Tol, S.
White, G.
author_sort Weeren, R.
building Curtin Institutional Repository
collection Online Access
description LOFAR, the Low-Frequency Array, is a powerful new radio telescope operating between 10 and 240 MHz. LOFAR allows detailed sensitive high-resolution studies of the low-frequency radio sky. At the same time LOFAR also provides excellent short baseline coverage to map diffuse extended emission. However, producing highquality deep images is challenging due to the presence of direction-dependent calibration errors, caused by imperfect knowledge of the station beam shapes and the ionosphere. Furthermore, the large data volume and presence of station clock errors present additional difficulties. In this paper we present a new calibration scheme, which we name facet calibration, to obtain deep high-resolution LOFAR High Band Antenna images using the Dutch part of the array. This scheme solves and corrects the direction-dependent errors in a number of facets that cover the observed field of view. Facet calibration provides close to thermal noise limited images for a typical 8 hr observing run at ~5' resolution, meeting the specifications of the LOFAR Tier-1 northern survey.
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format Journal Article
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institution Curtin University Malaysia
institution_category Local University
last_indexed 2025-11-14T10:59:48Z
publishDate 2016
publisher Institute of Physics Publishing
recordtype eprints
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spelling curtin-20.500.11937-742042019-07-22T03:13:43Z Lofar Facet Calibration Weeren, R. Williams, W. Hardcastle, M. Shimwell, T. Rafferty, D. Sabater, J. Heald, G. Sridhar, S. Dijkema, T. Brunetti, G. Brüggen, M. Andrade-Santos, F. Ogrean, G. Röttgering, H. Dawson, W. Forman, W. Gasperin, F. Jones, C. Miley, G. Rudnick, L. Sarazin, C. Bonafede, A. Best, P. Birzan, L. Cassano, R. Chyzy, K. Croston, J. Ensslin, T. Ferrari, C. Hoeft, M. Horellou, C. Jarvis, M. Kraft, R. Mevius, M. Intema, Hubertus Murray, S. Orrú, E. Pizzo, R. Simionescu, A. Stroe, A. Tol, S. White, G. LOFAR, the Low-Frequency Array, is a powerful new radio telescope operating between 10 and 240 MHz. LOFAR allows detailed sensitive high-resolution studies of the low-frequency radio sky. At the same time LOFAR also provides excellent short baseline coverage to map diffuse extended emission. However, producing highquality deep images is challenging due to the presence of direction-dependent calibration errors, caused by imperfect knowledge of the station beam shapes and the ionosphere. Furthermore, the large data volume and presence of station clock errors present additional difficulties. In this paper we present a new calibration scheme, which we name facet calibration, to obtain deep high-resolution LOFAR High Band Antenna images using the Dutch part of the array. This scheme solves and corrects the direction-dependent errors in a number of facets that cover the observed field of view. Facet calibration provides close to thermal noise limited images for a typical 8 hr observing run at ~5' resolution, meeting the specifications of the LOFAR Tier-1 northern survey. 2016 Journal Article http://hdl.handle.net/20.500.11937/74204 10.3847/0067-0049/223/1/2 Institute of Physics Publishing fulltext
spellingShingle Weeren, R.
Williams, W.
Hardcastle, M.
Shimwell, T.
Rafferty, D.
Sabater, J.
Heald, G.
Sridhar, S.
Dijkema, T.
Brunetti, G.
Brüggen, M.
Andrade-Santos, F.
Ogrean, G.
Röttgering, H.
Dawson, W.
Forman, W.
Gasperin, F.
Jones, C.
Miley, G.
Rudnick, L.
Sarazin, C.
Bonafede, A.
Best, P.
Birzan, L.
Cassano, R.
Chyzy, K.
Croston, J.
Ensslin, T.
Ferrari, C.
Hoeft, M.
Horellou, C.
Jarvis, M.
Kraft, R.
Mevius, M.
Intema, Hubertus
Murray, S.
Orrú, E.
Pizzo, R.
Simionescu, A.
Stroe, A.
Tol, S.
White, G.
Lofar Facet Calibration
title Lofar Facet Calibration
title_full Lofar Facet Calibration
title_fullStr Lofar Facet Calibration
title_full_unstemmed Lofar Facet Calibration
title_short Lofar Facet Calibration
title_sort lofar facet calibration
url http://hdl.handle.net/20.500.11937/74204