Journal article

Measuring phased-array antenna beampatterns with high dynamic range for the Murchison Widefield Array using 137MHz ORBCOMM satellites

AR Neben, RF Bradley, JN Hewitt, G Bernardi, JD Bowman, F Briggs, RJ Cappallo, AA Deshpande, R Goeke, LJ Greenhill, BJ Hazelton, M Johnston-Hollitt, DL Kaplan, CJ Lonsdale, SR McWhirter, DA Mitchell, MF Morales, E Morgan, D Oberoi, SM Ord Show all



Detection of the fluctuations in a 21cm line emission from neutral hydrogen during the Epoch of Reionization in thousand hour integrations poses stringent requirements on calibration and image quality, both of which necessitate accurate primary beam models. The Murchison Widefield Array (MWA) uses phased-array antenna elements which maximize collecting area at the cost of complexity. To quantify their performance, we have developed a novel beam measurement system using the 137MHz ORBCOMM satellite constellation and a reference dipole antenna. Using power ratio measurements, we measure the in situ beampattern of the MWA antenna tile relative to that of the reference antenna, canceling the var..

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University of Melbourne Researchers


Awarded by NSF

Awarded by U.S. National Science Foundation

Awarded by Australian Research Council (LIEF)

Awarded by U.S. Air Force Office of Scientific Research

Awarded by Centre for All-Sky Astrophysics (an Australian Research Council Centre of Excellence)

Awarded by Victoria University of Wellington from the New Zealand Ministry of Economic Development

Awarded by Victoria University of Wellington (from the IBM Shared University Research grant)

Funding Acknowledgements

This work was supported by NSF grant AST-0821321, the Marble Astrophysics Fund, and the MIT School of Science. We thank Pat Klima, Bang Dinh Nhan, and the staff at the National Radio Astronomy Observatory-Green Bank for assistance in setting up and debugging our experiment and Haoxuan Zheng, Aaron Ewall-Wice, Josh Dillon, Lu Feng, and Daniel Jacobs for helpful discussions. We thank Nithyanandan Thyagarajan, Josh Dillon, Adrian Sutinjo, Tim Colegate, and the anonymous referees for very helpful comments on our manuscript. The National Radio Astronomy Observatory is a facility of the National Science Foundation operated under cooperative agreement by Associated Universities, Inc. We would like to extend our appreciation to Ed LeFave, Alan Fenn, David Bruno, John Glover, and Jeffrey Herd at MIT Lincoln Laboratory for their support of anechoic chamber tests of MWA prototype antenna tiles. This scientific work makes use of the Murchison Radio-astronomy Observatory, operated by CSIRO. We acknowledge the Wajarri Yamatji people as the traditional owners of the observatory site. Support for the MWA comes from the U.S. National Science Foundation (grants AST-0457585, PHY-0835713, CAREER-0847753, and AST-0908884), the Australian Research Council (LIEF grants LE0775621 and LE0882938), the U.S. Air Force Office of Scientific Research (grant FA9550-0510247), and the Centre for All-Sky Astrophysics (an Australian Research Council Centre of Excellence funded by grant CE110001020). Support is also provided by the Smithsonian Astrophysical Observatory, the MIT School of Science, the Raman Research Institute, the Australian National University, and the Victoria University of Wellington (via grant MED-E1799 from the New Zealand Ministry of Economic Development and an IBM Shared University Research grant). The Australian Federal government provides additional support via the Commonwealth Scientific and Industrial Research Organisation (CSIRO), National Collaborative Research Infrastructure Strategy, Education Investment Fund, and the Australia India Strategic Research Fund, and Astronomy Australia Limited, under contract to Curtin University. We acknowledge the iVEC Petabyte Data Store, the Initiative in Innovative Computing and the CUDA Center for Excellence sponsored by NVIDIA at Harvard University, and the International Centre for Radio Astronomy Research (ICRAR), a joint venture of Curtin University and the University of Western Australia, funded by the Western Australian State government. Data on which figures and tables herein are based may be obtained by contacting the corresponding author Abraham Neben (