Automated Detection of Antenna Malfunctions in Large‐<i>N</i> Interferometers: A Case Study With the Hydrogen Epoch of Reionization Array

Storer, Dara; Dillon, Joshua S.; Jacobs, Daniel C.; Morales, M. F.; Hazelton, B. J.; Ewall‐Wice, Aaron; Abdurashidova, Zara; Aguirre, James E.; Alexander, Paul; Ali, Zaki S.; Balfour, Yanga; Beardsley, Adam P.; Bernardi, G.; Billings, Tashalee S.; Bowman, Judd D.; Bradley, Richard F.; Bull, Philip; Burba, Jacob; Carey, S. H.; Carilli, C. L.; Cheng, Carina; DeBoer, David R.; Acedo, Eloy Lera; Dexter, Matt; Dynes, Scott; Ely, John; Fagnoni, Nicolas; Fritz, Randall; Furlanetto, Steven R.; Gale‐Sides, Kingsley; Glendenning, Brian; Gorthi, Deepthi; Greig, Bradley; Grobbelaar, Jasper; Halday, Ziyaad; Hewitt, Jacqueline N.; Hickish, J.; Huang, Tian; Josaitis, Alec; Julius, Austin; Kariseb, MacCalvin; Kern, Nicholas S.; Kerrigan, Joshua; Kittiwisit, Piyanat; Kohn, Saul A.; Kolopanis, Matthew; Lanman, Adam; Plante, Paul La; Liu, Adrian; Loots, Anita; MacMahon, David H. E.; Malan, Lourence; Malgas, Cresshim; Martinot, Zachary E.; Mesinger, Andrei; Molewa, Mathakane; Mosiane, Tshegofalang; Murray, Steven; Neben, Abraham R.; Nikolic, Bojan; Nunhokee, Chuneeta D.; Parsons, Aaron; Pascua, Robert; Patra, Nipanjana; Pieterse, Samantha; Pober, Jonathan C.; Razavi-Ghods, N.; Riley, Daniel; Robnett, James; Rosie, Kathryn; Santos, Mário G.; Sims, Peter; Singh, Saurabh; Smith, Craig; Tan, Jianrong; Thyagarajan, Nithyanandan; Williams, Peter K. G.; Zheng, Haoxuan

doi:10.1029/2021rs007376

Cited by 3 publications

(4 citation statements)

References 40 publications

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“…It identified malfunctioning antennas by looking for antennas participating in baselines that were either outliers in total visibility power, or had visibility amplitude spectra significantly different from other baselines measuring the same physical separation on the ground. This procedure ultimately informed the most rigorous identification of malfunctioning antennas described in Storer et al (2022), which was applied to HERA Phase II data. The results of nightly analysis were synthesized into a set of perantenna, per-night flags by the HERA commissioning team as part of an internal data release.…”

Section: Selection Of Antennasmentioning

confidence: 99%

Improved Constraints on the 21 cm EoR Power Spectrum and the X-Ray Heating of the IGM with HERA Phase I Observations

Abdurashidova

Adams

Aguirre

et al. 2023

ApJ

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We report the most sensitive upper limits to date on the 21 cm epoch of reionization power spectrum using 94 nights of observing with Phase I of the Hydrogen Epoch of Reionization Array (HERA). Using similar analysis techniques as in previously reported limits, we find at 95% confidence that Δ2(k = 0.34 h Mpc−1) ≤ 457 mK2 at z = 7.9 and that Δ2(k = 0.36 h Mpc−1) ≤ 3496 mK2 at z = 10.4, an improvement by a factor of 2.1 and 2.6, respectively. These limits are mostly consistent with thermal noise over a wide range of k after our data quality cuts, despite performing a relatively conservative analysis designed to minimize signal loss. Our results are validated with both statistical tests on the data and end-to-end pipeline simulations. We also report updated constraints on the astrophysics of reionization and the cosmic dawn. Using multiple independent modeling and inference techniques previously employed by HERA Collaboration, we find that the intergalactic medium must have been heated above the adiabatic cooling limit at least as early as z = 10.4, ruling out a broad set of so-called “cold reionization” scenarios. If this heating is due to high-mass X-ray binaries during the cosmic dawn, as is generally believed, our result’s 99% credible interval excludes the local relationship between soft X-ray luminosity and star formation and thus requires heating driven by evolved low-metallicity stars.

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Section: Selection Of Antennasmentioning

confidence: 99%

Improved Constraints on the 21 cm EoR Power Spectrum and the X-Ray Heating of the IGM with HERA Phase I Observations

Abdurashidova

Adams

Aguirre

et al. 2023

ApJ

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“…Autocorrelation notebooks assess power levels that are too low (malfunctioning gain stage or broken fiber), too high (too much gain causing saturation), or show an abnormal passband for a spectrum, which may indicate a problem with the feed. Example cross-correlation metrics include redundancy between repeated baselines and correlation of antennas (Storer et al 2022). These metrics are useful as automated functions to flag broken or misbehaving antennas, but they are also useful for observers to identify unusual phenomena by eye.…”

Section: Notebooks and Quality Metricsmentioning

confidence: 99%

“…This was particularly strong between antennas within the same node, and consequently within the same PAM receiver rack. The correlation is easily seen when plotting the visibility matrix normalized by the auto correlations (Storer et al 2022). This excess varied in time much faster than expected variation due to the sky suggesting another source of common mode or variation in the cross coupling path.…”

Section: Common Modementioning

confidence: 99%

Hydrogen Epoch of Reionization Array (HERA) Phase II Deployment and Commissioning

Berkhout,

Jacobs,

Abdurashidova

et al. 2024

PASP

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This paper presents the design and deployment of the Hydrogen Epoch of Reionization Array (HERA) phase II system. HERA is designed as a staged experiment targeting 21 cm emission measurements of the Epoch of Reionization. First results from the phase I array are published as of early 2022, and deployment of the phase II system is nearing completion. We describe the design of the phase II system and discuss progress on commissioning and future upgrades. As HERA is a designated Square Kilometre Array pathfinder instrument, we also show a number of “case studies” that investigate systematics seen while commissioning the phase II system, which may be of use in the design and operation of future arrays. Common pathologies are likely to manifest in similar ways across instruments, and many of these sources of contamination can be mitigated once the source is identified.

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“…We take the nightly antenna flags from H22a to flag triads formed by such antennas. These flags are informed by specially designed metrics for detecting malfunctioning antennas (Storer et al 2022) and by the redundant-baseline calibration process of H22a which is able to identify particularly non-redundant antennas (cf. Dillon et al 2020).…”

Section: Data Flaggingmentioning

confidence: 99%

Search for the Epoch of Reionization with HERA: upper limits on the closure phase delay power spectrum

Keller

Nikolic

Thyagarajan

et al. 2023

Monthly Notices of the Royal Astronomical Society

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Radio interferometers aiming to measure the power spectrum of the redshifted 21 cm line during the Epoch of Reionisation (EoR) need to achieve an unprecedented dynamic range to separate the weak signal from overwhelming foreground emissions. Calibration inaccuracies can compromise the sensitivity of these measurements to the effect that a detection of the EoR is precluded. An alternative to standard analysis techniques makes use of the closure phase, which allows one to bypass antenna-based direction-independent calibration. Similarly to standard approaches, we use a delay spectrum technique to search for the EoR signal. Using 94 nights of data observed with Phase I of the Hydrogen Epoch of Reionization Array (HERA), we place approximate constraints on the 21 cm power spectrum at z = 7.7. We find at 95% confidence that the 21 cm EoR brightness temperature is ≤(372)2 ‘pseudo’ mK2 at 1.14 ‘pseudo’ h Mpc−1, where the ‘pseudo’ emphasises that these limits are to be interpreted as approximations to the actual distance scales and brightness temperatures. Using a fiducial EoR model, we demonstrate the feasibility of detecting the EoR with the full array. Compared to standard methods, the closure phase processing is relatively simple, thereby providing an important independent check on results derived using visibility intensities, or related.

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Automated Detection of Antenna Malfunctions in Large‐N Interferometers: A Case Study With the Hydrogen Epoch of Reionization Array

Cited by 3 publications

References 40 publications

Improved Constraints on the 21 cm EoR Power Spectrum and the X-Ray Heating of the IGM with HERA Phase I Observations

Improved Constraints on the 21 cm EoR Power Spectrum and the X-Ray Heating of the IGM with HERA Phase I Observations

Hydrogen Epoch of Reionization Array (HERA) Phase II Deployment and Commissioning

Search for the Epoch of Reionization with HERA: upper limits on the closure phase delay power spectrum

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