Dr. Hari B. Subedi Profile

Dr. Hari B. Subedi

at NASA Goddard Space Flight Ctr

SPIE Involvement:

Author

Publications (20)

Proceedings Article | 24 August 2024 Poster

Repurposing PISCES for broadband wavefront sensing and control experiments on the ExoSpec Project testbed

Harrison Bradley, Neil Zimmerman, Roser Juanola-Parramon, Qian Gong, Michael McElwain, Tyler Groff, Hari Subedi, George Hilton

Proceedings Volume 13092, 130926A (2024) https://doi.org/10.1117/12.3020180

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Proceedings Article | 23 August 2024 Poster + Paper

ExoSpec project: exoplanet spectroscopy technologies for the Habitable Worlds Observatory at NASA’s Goddard Space Flight Center

Michael McElwain, Neil Zimmerman, Bernard Rauscher, Tyler Groff, Avi Mandell, Eleonora Alei, Tyler Baines, Joshua Berrier, Harrison Bradley, Qian Gong, Alex Howe, Roser Juanola-Parramon, Emily Kan, Daniel Kelly, Vincent Kofman, Breann Sitarski, Christopher Stark, Hari Subedi, Geronimo Villanueva, Scott Will

Proceedings Volume 13092, 130925K (2024) https://doi.org/10.1117/12.3020211

KEYWORDS: Exoplanets, Coronagraphy, Deformable mirrors, Iterated function systems, Observatories, Charge-coupled devices, Spectroscopy, Actuators, Equipment, CCD image sensors

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Proceedings Article | 23 August 2024 Paper

Experimental verification of the parabolic deformable mirror for the ExoSpec project

Hari Subedi, Tyler Groff, Scott Will, Qian Gong, Joshua Berrier, Michael McElwain, Roser Juanola-Parramon

Proceedings Volume 13092, 1309260 (2024) https://doi.org/10.1117/12.3018914

KEYWORDS: Coronagraphy, Wavefronts, Wavefront sensors, Wavefront errors, Optical alignment, Deformable mirrors, Actuators, Optical components, Interferometers, Wavefront aberrations

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Proceedings Article | 23 August 2024 Presentation + Paper

How to train your Jacobian: least-squares system identiﬁcation for space-based coronagraphy

Scott Will, Meiji Nguyen, Raphaël Pourcelot, Hari Subedi, Tyler Groff, Rémi Soummer

Proceedings Volume 13092, 1309226 (2024) https://doi.org/10.1117/12.3020344

KEYWORDS: Electric fields, Coronagraphy, System identification, Expectation maximization algorithms, Simulations, Exoplanets, Mathematical optimization, Adaptive control, Wavefront compensation, Wavefront sensors

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Proceedings Article | 6 October 2023 Presentation

High-contrast imager for complex aperture telescopes (HiCAT): 10. Broadband Zernike wavefront sensor under natural and artificial drifts

Raphaël Pourcelot, Emiel Por, Mamadou N'Diaye, Benjamin Buralli, Marcel Carbillet, Kjetil Dohlen, Sylvain Egron, Marc Ferrari, Rachel Fox, Rob Gontrum, Iva Laginja, Meiji Nguyen, Bryony Nickson, Marshall Perrin, Peter Petrone, Laurent Pueyo, Susan Redmond, Ananya Sahoo, Anand Sivaramakrishnan, Hari Subedi, Sam Weinstock, Scott Will, Rémi Soummer, John Hagopian

Proceedings Volume 12680, 126801F (2023) https://doi.org/10.1117/12.2677790

KEYWORDS: Wavefront sensors, Telescopes, Imaging systems, Coronagraphy, Deformable mirrors, Stars, Monochromatic aberrations, Image segmentation, Wavefront aberrations, Observatories

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Proceedings Article | 6 October 2023 Presentation

RST CGI: final verification and calibration of prism and polarizer flight units

Tyler Groff, Neil Zimmerman, Hari Subedi, John Titus, Dylan Bell, Guangjun Gao, Samuel Gaylin, Nicholas Nicolaeff, Toru Yamada, Motohide Tamura

Proceedings Volume 12680, 126800W (2023) https://doi.org/10.1117/12.2677576

KEYWORDS: Prisms, Calibration, Polarizers, Polarization, Spectroscopes, Spectral resolution, Equipment, Target detection, Space telescopes, Signal to noise ratio

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Proceedings Article | 5 October 2023 Presentation + Paper

First generation parabolic deformable mirror for the ExoSpec project

Hari Subedi, Tyler Groff, Scott Will, Roser Juanola-Parramon

Proceedings Volume 12680, 1268013 (2023) https://doi.org/10.1117/12.2677625

KEYWORDS: Wavefronts, Actuators, Deformable mirrors, Wavefront aberrations, Simulations, Parabolic mirrors, Optical alignment, Coronagraphy, Mirrors, Manufacturing

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Proceedings Article | 5 October 2023 Presentation + Paper

Nancy Grace Roman Space Telescope coronagraph instrument overview and status

Vanessa Bailey, Eduardo Bendek, Brian Monacelli, Caleb Baker, Gasia Bedrosian, Eric Cady, Ewan Douglas, Tyler Groff, Sergi Hildebrandt, N. Jeremy Kasdin, John Krist, Bruce Macintosh, Bertrand Mennesson, Patrick Morrissey, Ilya Poberezhskiy, Hari Subedi, Jason Rhodes, Aki Roberge, Marie Ygouf, Robert Zellem, Feng Zhao, Neil Zimmerman

Proceedings Volume 12680, 126800T (2023) https://doi.org/10.1117/12.2679036

KEYWORDS: Coronagraphy, Equipment, Mirrors, Optical benches, Wavefront sensors, Deformable mirrors, Cameras, Prisms, Observatories, Wavefront errors

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Proceedings Article | 5 October 2023 Presentation + Paper

High-contrast Jacobian-free wavefront control: simulations, experimental results, and extensions to adaptive control

Scott Will, Tyler Groff, Rémi Soummer, Hari Subedi, Laurent Pueyo, Marshall Perrin, Emiel Por, Neil Zimmerman, Michael McElwain, Christopher Stark, Roser Juanola-Parramon

Proceedings Volume 12680, 126801E (2023) https://doi.org/10.1117/12.2677396

KEYWORDS: Coronagraphy, Actuators, Simulations, Wavefronts, Mathematical optimization, Algorithm development, Matrices, Observatories, Wavefront sensors, Wavefront reconstruction, Exoplanets, Computational imaging

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Proceedings Article | 27 August 2022 Presentation + Paper

High-contrast imager for complex aperture telescopes (HiCAT): 8. Dark zone demonstration with simultaneous closed-loop low-order wavefront sensing and control

Rémi Soummer, Emiel Por, Raphaël Pourcelot, Susan Redmond, Iva Laginja, Scott Will, Marshall Perrin, Laurent Pueyo, Ananya Sahoo, Peter Petrone, Keira Brooks, Rachel Fox, Alex Klein, Bryony Nickson, Thomas Comeau, Marc Ferrari, Rob Gontrum, John Hagopian, Lucie Leboulleux, Daniel Leongomez, Joe Lugten, Laurent Mugnier, Mamadou N'Diaye, Meiji Nguyen, James Noss, Jean-François Sauvage, Nathan Scott, Anand Sivaramakrishnan, Hari Subedi, Sam Weinstock

Proceedings Volume 12180, 1218026 (2022) https://doi.org/10.1117/12.2630444

KEYWORDS: Coronagraphy, Wavefronts, Wavefront sensors, Telescopes, Phase retrieval

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Proceedings Article | 4 August 2021 Presentation

High-contrast imager for complex aperture telescopes (HiCAT): 7. Dark zone demonstration with fully segmented aperture coronagraph

Rémi Soummer, Iva Laginja, Scott Will, Marshall Perrin, James Noss, Emiel Por, Susan Redmond, Raphaël Pourcelot, Ananya Sahoo, Peter Petrone, Keira Brooks, Laurent Pueyo, Bryony Nickson, Matt Maclay, Gregory Brady, Thomas Comeau, Julia Fowler, Kelsey Glazer, Rob Gontrum, John Hagopian, Theo Jolivet, Maggie Kautz, Lucie Leboulleux, Evelyn McChesney, Laurent Mugnier, Mamadou N'Diaye, Meiji Nguyen, Heather Olszewski, Leonid Pogorelyuk, Jaret Prothro, Jean-François Sauvage, Nathan Scott, Ron Shiri, Anand Sivaramakrishnan, Hari Subedi, Sam Weinstock, Yinzi Xin, Rebecca Zhang

Proceedings Volume 11823, 118230T (2021) https://doi.org/10.1117/12.2594684

KEYWORDS: Image segmentation, Coronagraphy, Telescopes, Imaging systems, Wavefront sensors, Wavefronts, Deformable mirrors, Ultraviolet telescopes, Ultraviolet radiation, UV optics

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Proceedings Article | 7 January 2021 Paper

Parabolic deformable mirror testbed for the ExoSpec project

Hari Subedi, Roser Juanola-Parramon, Tyler Groff, John Hagopian

Proceedings Volume 11443, 114431E (2021) https://doi.org/10.1117/12.2562642

KEYWORDS: Deformable mirrors, Actuators, Exoplanets, Packaging, Coronagraphy, Space operations, Wavefront sensors, Optical components, Computer simulations, Device simulation

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Proceedings Article | 7 January 2021 Poster + Paper

Roman Space Telescope CGI: prism and polarizer characterization modes

Tyler Groff, Neil Zimmerman, Hari Subedi, Maxime Rizzo, John Titus, Jim Lyons, Dylan Bell, Samuel Gaylin, Guangjun Gao, Bert Pasquale, Nicholas Nicolaeff, Motohide Tamura, Fang Shi

Proceedings Volume 11443, 114433D (2021) https://doi.org/10.1117/12.2562925

KEYWORDS: Prisms, Polarizers, Polarization, Spectral calibration, Spectroscopes, Planets, Spectral resolution, Optical design, Calibration, Coronagraphy

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Proceedings Article | 15 December 2020 Poster + Paper

ExoSpec project: an exoplanet spectroscopy technology research collaboration based at NASA’s Goddard Space Flight Center and Ames Research Center

Neil Zimmerman, Michael McElwain, Tyler Groff, Roser Juanola-Parramon, Avi Mandell, Mark Marley, Bernard Rauscher, Hari Subedi, Tyler Baines, Natasha Batalha, Aki Roberge, Adam J. R. W. Smith, Christopher Stark, Nicholas Susemiehl

Proceedings Volume 11443, 114433T (2020) https://doi.org/10.1117/12.2562872

KEYWORDS: Exoplanets, Atmospheric modeling, Spectroscopes, Spectroscopy, Instrument modeling, Atmospheric sensing, Space operations, Wavefronts, Control systems, Sensor performance

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Proceedings Article | 9 September 2019 Presentation + Paper

Design and modeling of the off-axis parabolic deformable mirror laboratory

Hari Subedi, Roser Juanola-Parramon, Tyler Groff

Proceedings Volume 11117, 111171Z (2019) https://doi.org/10.1117/12.2530414

KEYWORDS: Deformable mirrors, Coronagraphy, Monochromatic aberrations, Actuators, Imaging systems, Wavefronts, Control systems, Optical aberrations, Mirrors, Telescopes

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Proceedings Article | 10 July 2018 Presentation

Modelling exoplanet detection with the LUVOIR coronagraph (Conference Presentation)

Roser Juanola-Parramon, Neil Zimmerman, Maxime Rizzo, Hari Subedi, Giada Arney, Tyler Groff, Laurent Pueyo, Chris Stark, Rémi Soummer, Matthew Bolcar, Aki Roberge

Proceedings Volume 10698, 1069810 (2018) https://doi.org/10.1117/12.2312837

KEYWORDS: Coronagraphy, Exoplanetary science, Modeling, Stars, Wavefronts, Spectral models, Planetary systems, Tolerancing

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Proceedings Article | 1 September 2017 Presentation + Paper

Adaptive estimation of line-of-sight jitter disturbance

Hari Subedi, Peter Varnai, N. Jeremy Kasdin

Proceedings Volume 10400, 104000S (2017) https://doi.org/10.1117/12.2273419

KEYWORDS: Wavefront sensors, Wavefronts, Space telescopes, Exoplanets, Control systems, Imaging systems, Telescopes, Deformable mirrors, Wavefront aberrations, Sensors, Adaptive control

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Proceedings Article | 29 July 2016 Paper

Sparse aperture mask wavefront sensor testbed results

Hari Subedi, Neil Zimmerman, N. Jeremy Kasdin, A. J. Riggs

Proceedings Volume 9904, 990464 (2016) https://doi.org/10.1117/12.2232015

KEYWORDS: Wavefront sensors, Space telescopes, Relays, Coronagraphy, Monochromatic aberrations, Error analysis, Actuators, Sensors, Telescopes, Wavefronts

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Proceedings Article | 16 September 2015 Paper

Sparse aperture mask for low order wavefront sensing

Hari Subedi, Neil Zimmerman, N. Jeremy Kasdin, Kathleen Cavanagh, A. J. Riggs

Proceedings Volume 9605, 96051W (2015) https://doi.org/10.1117/12.2187685

KEYWORDS: Wavefront sensors, Coronagraphy, Sensors, Monochromatic aberrations, Error analysis, Wavefronts, Exoplanets, Space telescopes, Signal to noise ratio, Wavefront aberrations

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SPIE Journal Paper | 12 June 2015 Open Access

Coronagraph-integrated wavefront sensing with a sparse aperture mask

Hari Subedi, Neil Zimmerman, N. Jeremy Kasdin, Kathleen Cavanagh, A. J. Eldorado Riggs

JATIS, Vol. 1, Issue 03, 039001, (June 2015) https://doi.org/10.1117/12.10.1117/1.JATIS.1.3.039001

KEYWORDS: Coronagraphy, Wavefronts, Sensors, Wavefront sensors, Error analysis, Point spread functions, Monochromatic aberrations, Exoplanets, Charge-coupled devices, Wave propagation

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