Dual polarization measurements of MWA beampatterns at 137 MHz
| Autor: | J. L. B. Line, Nichole Barry, Andrew R. Williams, D. Kenney, Rachel L. Webster, D. Ung, A. McPhail, A. Chokshi |
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| Rok vydání: | 2021 |
| Předmět: |
Physics
business.industry Dynamic range Phased array Astrophysics::Instrumentation and Methods for Astrophysics FOS: Physical sciences 020206 networking & telecommunications Astronomy and Astrophysics Murchison Widefield Array 02 engineering and technology 01 natural sciences Optics Dual-polarization interferometry Space and Planetary Science 0103 physical sciences 0202 electrical engineering electronic engineering information engineering Astronomical interferometer Calibration Astrophysics - Instrumentation and Methods for Astrophysics business Instrumentation and Methods for Astrophysics (astro-ph.IM) 010303 astronomy & astrophysics Beam (structure) Radio astronomy |
| Zdroj: | Monthly Notices of the Royal Astronomical Society. 502:1990-2004 |
| ISSN: | 1365-2966 0035-8711 |
| Popis: | The wide adoption of low-frequency radio interferometers as a tool for deeper and higher resolution astronomical observations has revolutionised radio astronomy. Despite their construction from static, relatively simple dipoles, the sheer number of distinct elements introduces new, complicated instrumental effects. Their necessary remote locations exacerbate failure rates, while electronic interactions between the many adjacent receiving elements can lead to non-trivial instrumental effects. The Murchison Widefield Array (MWA) employs phased array antenna elements (tiles), which improve collecting area at the expense of complex beam shapes. Advanced electromagnetic simulations have produced the Fully Embedded Element (FEE) simulated beam model which has been highly successful in describing the ideal beam response of MWA antennas. This work focuses on the relatively unexplored aspect of various in-situ, environmental perturbations to beam models and represents the first large-scale, in-situ, all-sky measurement of MWA beam shapes at multiple polarizations and pointings. Our satellite based beam measurement approach enables all-sky beam response measurements with a dynamic range of \sim 50 dB, at 137 MHz. 16 pages, 15 figures, accepted for publication by the Monthly Notices of the Royal Astronomical Society (15/01/2021). For EMBERS code see: https://github.com/amanchokshi/EMBERS . For EMBERS documentation see: https://embers.readthedocs.io |
| Databáze: | OpenAIRE |
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