Algorithms for FFT Beamforming Radio Interferometers
Name
Masui_2019_ApJ_879_16.pdf
Description
Published version
Size
563.03 KB
Format
Adobe PDF
Checksum (MD5)
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Author(s)
Masui, Kiyoshi
Shaw, J Richard
Ng, Cherry
Smith, Kendrick M
Vanderlinde, Keith
Paradise, Adiv
Date Issued
June 2019
Journal
Astrophysical Journal
Publisher
American Astronomical Society
Citation
Masui, Kiyoshi W. et al., "Algorithms for FFT Beamforming Radio Interferometers." Astrophysical Journal 879, 1 (July 2019): 16 ©2019 Authors
Version
Final published version
Abstract
Radio interferometers consisting of identical antennas arranged on a regular lattice permit fast Fourier transform beamforming, which reduces the correlation cost fromω (n2) in the number of antennas toω(n log n). We develop a formalism for describing this process and apply this formalism to derive a number of algorithms with a range of observational applications. These include algorithms for forming arbitrarily pointed tied-array beams from the regularly spaced Fourier transform-formed beams, sculpting the beams to suppress sidelobes while only losing percent-level sensitivity, and optimally estimating the position of a detected source from its observed brightness in the set of beams. We also discuss the effect that correlations in the visibility-space noise, due to cross talk and sky contributions, have on the optimality of Fourier transform beamforming, showing that it does not strictly preserve the sky information of the n2 correlation, even for an idealized array. Our results have applications to a number of upcoming interferometers, in particular the Canadian Hydrogen Intensity Mapping Experiment-Fast Radio Burst (CHIME/FRB) project. ©2019. The American Astronomical Society. All rights reserved.
MIT Department
MIT Kavli Institute for Astrophysics and Space Research
Massachusetts Institute of Technology. Department of Physics
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Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use.
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DOI of Published Version
https://doi.org/10.3847/1538-4357/AB229E
