학술논문
The Murchison Widefield Array: Design Overview
Document Type
Periodical
Author
Lonsdale, C. J.; Cappallo, R. J.; Morales, M. F.; Briggs, F. H.; Benkevitch, L.; Bowman, J. D.; Bunton, J. D.; Burns, S.; Corey, B. E.; deSouza, L.; Doeleman, S. S.; Derome, M.; Deshpande, A.; Gopala, M. R.; Greenhill, L. J.; Herne, D. E.; Hewitt, J. N.; Kamini, P. A.; Kasper, J. C.; Kincaid, B. B.; Kocz, J.; Kowald, E.; Kratzenberg, E.; Kumar, D.; Lynch, M. J.; Madhavi, S.; Matejek, M.; Mitchell, D. A.; Morgan, E.; Oberoi, D.; Ord, S.; Pathikulangara, J.; Prabu, T.; Rogers, A. E. E.; Roshi, A.; Salah, J. E.; Sault, R. J.; Shankar, N. U.; Srivani, K. S.; Stevens, J.; Tingay, S.; Vaccarella, A.; Waterson, M.; Wayth, R. B.; Webster, R. L.; Whitney, A. R.; Williams, A.; Williams, C.
Source
Proceedings of the IEEE Proc. IEEE Proceedings of the IEEE. 97(8):1497-1506 Aug, 2009
Subject
Language
ISSN
0018-9219
1558-2256
1558-2256
Abstract
The Murchison Widefield Array is a dipole-based aperture array synthesis telescope designed to operate in the 80–300 MHz frequency range. It is capable of a wide range of science investigations but is initially focused on three key science projects: detection and characterization of three-dimensional brightness temperature fluctuations in the 21 cm line of neutral hydrogen during the epoch of reionization (EoR) at redshifts from six to ten; solar imaging and remote sensing of the inner heliosphere via propagation effects on signals from distant background sources; and high-sensitivity exploration of the variable radio sky. The array design features 8192 dual-polarization broadband active dipoles, arranged into 512 “tiles” comprising 16 dipoles each. The tiles are quasi-randomly distributed over an aperture 1.5 km in diameter, with a small number of outliers extending to 3 km. All tile–tile baselines are correlated in custom field-programmable gate array based hardware, yielding a Nyquist-sampled instantaneous monochromatic uv coverage and unprecedented point spread function quality. The correlated data are calibrated in real time using novel position-dependent self-calibration algorithms. The array is located in the Murchison region of outback Western Australia. This region is characterized by extremely low population density and a superbly radio-quiet environment, allowing full exploitation of the instrumental capabilities.