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Your search keyword '"Neben, Abraham R."' showing total 6 results
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6 results on '"Neben, Abraham R."'

1. Automated Detection of Antenna Malfunctions in Large-N Interferometers: A Case Study with the Hydrogen Epoch of Reionization Array

Author

Storer, Dara, Dillon, Joshua S., Jacobs, Daniel C., Morales, Miguel F., Hazelton, Bryna J., Ewall-Wice, Aaron, Abdurashidova, Zara, Aguirre, James E., Alexander, Paul, Ali, Zaki S., Balfour, Yanga, Beardsley, Adam P., Bernardi, Gianni, Billings, Tashalee S., Bowman, Judd D., Bradley, Richard F., Bull, Philip, Burba, Jacob, Carey, Steven, Carilli, Chris L., Cheng, Carina, DeBoer, David R., Acedo, Eloy de 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, Jack, Huang, Tian, Josaitis, Alec, Julius, Austin, Kariseb, MacCalvin, Kern, Nicholas S., Kerrigan, Joshua, Kittiwisit, Piyanat, Kohn, Saul A., Kolopanis, Matthew, Lanman, Adam, La Plante, Paul, Liu, Adrian, Loots, Anita, MacMahon, David, Malan, Lourence, Malgas, Cresshim, Martinot, Zachary E., Mesinger, Andrei, Molewa, Mathakane, Mosiane, Tshegofalang, Murray, Steven G., Neben, Abraham R., Nikolic, Bojan, Nunhokee, Chuneeta Devi, Parsons, Aaron R., Pascua, Robert, Patra, Nipanjana, Pieterse, Samantha, Pober, Jonathan C., Razavi-Ghods, Nima, Riley, Daniel, Robnett, James, Rosie, Kathryn, Santos, Mario G., Sims, Peter, Singh, Saurabh, Smith, Craig, Tan, Jianrong, Thyagarajan, Nithyanandan, Williams, Peter K. G., and Zheng, Haoxuan

Subjects
Astrophysics - Instrumentation and Methods for Astrophysics, Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract

We present a framework for identifying and flagging malfunctioning antennas in large radio interferometers. We outline two distinct categories of metrics designed to detect outliers along known failure modes of large arrays: cross-correlation metrics, based on all antenna pairs, and auto-correlation metrics, based solely on individual antennas. We define and motivate the statistical framework for all metrics used, and present tailored visualizations that aid us in clearly identifying new and existing systematics. We implement these techniques using data from 105 antennas in the Hydrogen Epoch of Reionization Array (HERA) as a case study. Finally, we provide a detailed algorithm for implementing these metrics as flagging tools on real data sets., Comment: 31 pages, 17 figures

Published
2021
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2. HI 21cm Cosmology and the Bi-spectrum: Closure Diagnostics in Massively Redundant Interferometric Arrays

Author

Carilli, C. L., Nikolic, Bojan, Thyagarajan, Nithyanandan, Gale-Sides, K., Abdurashidova, Zara, Aguirre, James E., Alexander, Paul, Ali, Zaki S., Balfour, Yanga, Beardsley, Adam P., Bernardi, Gianni, Bowman, Judd D., Bradley, Richard F., Burba, Jacob, Cheng, Carina, DeBoer, David R., Dexter, Matt, de~Lera~Acedo, Eloy, Dillon, Joshua S., Ewall-Wice, Aaron, Fadana, Gcobisa, Fagnoni, Nicolas, Fritz, Randall, Furlanetto, Steve R., Ghosh, Abhik, Glendenning, Brian, Greig, Bradley, Grobbelaar, Jasper, Halday, Ziyaad, Hazelton, Bryna J., Hewitt, Jacqueline N., Hickish, Jack, Jacobs, Daniel C., Julius, Austin, Kariseb, MacCalvin, Kohn, Saul A., Kolopanis, Mathew, Lekalake, Telalo, Liu, Adrian, Loots, Anita, MacMahon, David, Malan, Lourence, Malgas, Cresshim, Maree, Matthys, Martinot, Zachary, Matsetela, Eunice, Mesinger, Andrei, Molewa, Mathakane, Morales, Miguel F., Neben, Abraham R., Parsons, Aaron R., Patra, Nipanjana, Pieterse, Samantha, La Plante, Paul, Pober, Jonathan C., Razavi-Ghods, Nima, Ringuette, Jon, Robnett, James, Rosie, Kathryn, Sell, Raddwine, Sims, Peter, Smith, Craig, Syce, Angelo, Williams, Peter K. ~G., and Zheng, Haoxuan

Subjects
Astrophysics - Instrumentation and Methods for Astrophysics
Abstract

New massively redundant low frequency arrays allow for a novel investigation of closure relations in interferometry. We employ commissioning data from the Hydrogen Epoch of Reionization Array to investigate closure quantities in this densely packed grid array of 14m antennas operating at 100 MHz to 200 MHz. We investigate techniques that utilize closure phase spectra for redundant triads to estimate departures from redundancy for redundant baseline visibilities. We find a median absolute deviation from redundancy in closure phase across the observed frequency range of about 4.5deg. This value translates into a non-redundancy per visibility phase of about 2.6deg, using prototype electronics. The median absolute deviations from redundancy decrease with longer baselines. We show that closure phase spectra can be used to identify ill-behaved antennas in the array, independent of calibration. We investigate the temporal behavior of closure spectra. The Allan variance increases after a one minute stride time, due to passage of the sky through the primary beam of the transit telescope. However, the closure spectra repeat to well within the noise per measurement at corresponding local sidereal times (LST) from day to day. In future papers in this series we will develop the technique of using closure phase spectra in the search for the HI 21cm signal from cosmic reionization., Comment: 32 pages. 11 figures. Accepted to Radio Science

Published
2018
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3. Hydrogen Epoch of Reionization Array (HERA)

Author

DeBoer, David R., Parsons, Aaron R., Aguirre, James E., Alexander, Paul, Ali, Zaki S., Beardsley, Adam P., Bernardi, Gianni, Bowman, Judd D., Bradley, Richard F., Carilli, Chris L., Cheng, Carina, de Lera Acedo, Eloy, Dillon, Joshua S., Ewall-Wice, Aaron, Fadana, Gcobisa, Fagnoni, Nicolas, Fritz, Randall, Furlanetto, Steve R., Glendenning, Brian, Greig, Bradley, Grobbelaar, Jasper, Hazelton, Bryna J., Hewitt, Jacqueline N., Hickish, Jack, Jacobs, Daniel C., Julius, Austin, Kariseb, MacCalvin, Kohn, Saul A., Lekalake, Telalo, Liu, Adrian, Loots, Anita, MacMahon, David, Malan, Lourence, Malgas, Cresshim, Maree, Matthys, Martinot, Zachary, Mathison, Nathan, Matsetela, Eunice, Mesinger, Andrei, Morales, Miguel F., Neben, Abraham R., Patra, Nipanjana, Pieterse, Samantha, Pober, Jonathan C., Razavi-Ghods, Nima, Ringuette, Jon, Robnett, James, Rosie, Kathryn, Sell, Raddwine, Smith, Craig, Syce, Angelo, Tegmark, Max, Thyagarajan, Nithyanandan, Williams, Peter K. G., and Zheng, Haoxuan

Published
2017

5. The hydrogen epoch of reionization array dish III: measuring chromaticity of prototype element with reflectometry

Author

Patra, Nipanjana, Parsons, Aaron R., DeBoer, David R., Thyagarajan, Nithyanandan, Ewall-Wice, Aaron, Hsyu, Gilbert, Leung, Tsz Kuk, Day, Cherie K., de Lera Acedo, Eloy, Aguirre, James E., Alexander, Paul, Ali, Zaki S., Beardsley, Adam P., Bowman, Judd D., Bradley, Richard F., Carilli, Chris L., Cheng, Carina, Dillon, Joshua S., Fadana, Gcobisa, Fagnoni, Nicolas, Fritz, Randall, Furlanetto, Steve R., Glendenning, Brian, Greig, Bradley, Grobbelaar, Jasper, Hazelton, Bryna J., Jacobs, Daniel C., Julius, Austin, Kariseb, MacCalvin, Kohn, Saul A., Lebedeva, Anna, Lekalake, Telalo, Liu, Adrian, Loots, Anita, MacMahon, David, Malan, Lourence, Malgas, Cresshim, Maree, Matthys, Martinot, Zachary, Mathison, Nathan, Matsetela, Eunice, Mesinger, Andrei, Morales, Miguel F., Neben, Abraham R., Pieterse, Samantha, Pober, Jonathan C., Razavi-Ghods, Nima, Ringuette, Jon, Robnett, James, Rosie, Kathryn, Sell, Raddwine, Smith, Craig, Syce, Angelo, Tegmark, Max, Williams, Peter K. G., and Zheng, Haoxuan

Published
2018
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6. Structural thermal noise in gram-scale mirror oscillators.

Author

Neben, Abraham R., Bodiya, Timothy P., Wipf, Christopher, Oelker, Eric, Corbitt, Thomas, and Mavalvala, Nergis

Subjects
*SPECTRUM allocation, *UBIQUITOUS computing, *THERMAL noise, *RADIATION pressure, *INTERFEROMETRY
Abstract

The thermal noise associated with mechanical dissipation is a ubiquitous limitation to the sensitivity of precision experiments ranging from frequency stabilization to gravitational wave interferometry. We report on the thermal noise limits to the performance of 1 gm mirror oscillators that are part of a cavity optomechanics experiment to observe quantum radiation pressure noise. Thermal noise limits the observed cavity displacement spectrum from 80 Hz to 5 kHz. We present a calculation of the thermal noise, based on finite element analysis of the dissipation due to structural damping, and find it to be in excellent agreement with the experimental result. We conclude with the predicted thermal noise for an improved oscillator design, which should be capable of revealing the noise that arises from quantum backaction in this system. [ABSTRACT FROM AUTHOR]

Published
2012
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