Dr. Steven V. Penton Profile

Dr. Steven V. Penton

Calibration Scientist at Lab for Atmospheric and Space Physics

SPIE Involvement:

Author

Publications (19)

Proceedings Article | 27 August 2022 Poster + Paper

Solar spectral irradiance reconciliation of SORCE and TSIS1 SIM

Steven Victor Penton, Stéphane Béland, Jerry Harder, Erik Richard, Thomas Woods

Proceedings Volume 12180, 121803D (2022) https://doi.org/10.1117/12.2630361

KEYWORDS: Calibration, Sensors, Ultraviolet radiation, Photodiodes, Space operations, Radiometry

Read Abstract +

Proceedings Article | 25 August 2022 Poster + Paper

Observation planning to better track Solar instrument degradation

Stéphane Béland, Jerald Harder, Steven Penton, Erik Richard, Martin Snow

Proceedings Volume 12186, 121861N (2022) https://doi.org/10.1117/12.2629055

KEYWORDS: Calibration, Sensors, Sun, Ultraviolet radiation, Stars, Solar radiation models

Read Abstract +

Proceedings Article | 6 July 2018 Paper

COS2025: a strategy to extend the lifetime of the FUV detector on the Cosmic Origins Spectrograph

David Sahnow, Gisella de Rosa, John MacKenty, Cristina Oliveira, Steven Penton, Julia Roman-Duval

Proceedings Volume 10699, 106992U (2018) https://doi.org/10.1117/12.2312916

KEYWORDS: Sensors, Airglow, Microchannel plates, Spectrographs, Calibration, Hubble Space Telescope, Photons

Read Abstract +

The Cosmic Origins Spectrograph (COS) has been collecting data since soon after its installation on the Hubble Space Telescope in May 2009. The two-segment microchannel plate-based detector for the FUV channel is subject to gain sag, and eventually a permanent loss of efficiency at the locations where the largest number of counts have fallen. The initial strategy for the use of the detector was to maximize the scientific productivity of the instrument over the five-year design lifetime. This has been accomplished by periodically adjusting the high voltage and moving the spectra to a different location on the detector in order to spread the damage on the detector and thus minimize gain sag. The instrument is now well past this point and performing well, so in late 2016 we began to investigate ways to extend the life of the detector for as long as possible without seriously affecting the scientific performance. As a result of these studies, we adopted a new lifetime extension strategy when the spectra were moved to Lifetime Position 4 (LP4) in October 2017, and placed restrictions on the G130M observing modes that put Lyman-α airglow lines on the detector. Central wavelengths 1300, 1309, 1318, and 1327 are no longer permitted to illuminate Segment B of the detector, and G130M/1291 is permitted on that segment only for FP-POS values 3 and 4 in order to concentrate the damage to the detector. These changes limit the damage from gain sag “holes” due to airglow to only two locations on the detector, rather than the twenty at the previous LPs. In addition, we modified our previous approach of increasing the high voltage or changing LPs before any hole experienced a sensitivity loss of 5%, and will permit the two G130M/1291 holes to become permanently sagged, thus creating a new detector gap. Science programs that require wavelength coverage near the rest-frame Lyman-α region (1216 Å) can be executed at LP3. Observations with other gratings remain unaffected, but the wavelength coverage on Segment B for a single exposure will now include gaps due to the gain sag holes from the G130M/1291 observations. Models of gain loss as a function of exposure suggest that by adopting this strategy and giving up these small regions of the detector, we will be able to use LP4 productively for six or more years, as opposed to the ~2.5 years that was available at previous positions.

Proceedings Article | 18 July 2016 Paper

Correcting for errors due to walk and geometric distortion in the COS FUV detector

David Sahnow, Steven Penton, Thomas Ake, Gisella DeRosa, Justin Ely, Sean Lockwood, Cristina Oliveira, Rachel Plesha, Charles Proffitt, Julia Roman-Duval, Paule Sonnentrucker, Joanna Taylor, James White

Proceedings Volume 9905, 99052T (2016) https://doi.org/10.1117/12.2233091

KEYWORDS: Ultraviolet radiation, Point spread functions, Apodization, Niobium, Electroluminescent displays, Numerical simulations, Opacity, Imaging systems, Space telescopes, Binary data

Read Abstract +

Proceedings Article | 18 September 2015 Paper

Characterizing, controlling, and correcting distortions in the COS FUV detector

David Sahnow, George Becker, John Debes, Justin Ely, Sean Lockwood, Derck Massa, Cristina Oliveira, Steven Penton, Charles Proffitt, Julia Roman-Duval, Hugues Sana, Paule Sonnentrucker, Joanna Taylor

Proceedings Volume 9601, 96010Q (2015) https://doi.org/10.1117/12.2188529

KEYWORDS: Sensors, Calibration, Microchannel plates, Electronics, Target acquisition, Spectral calibration, Spectrographs, Hubble Space Telescope, Analog electronics, Dispersion

Read Abstract +

Proceedings Article | 26 September 2013 Paper

Characterization, modeling, and management of the COS FUV detector lifetime

David Sahnow, Alessandra Aloisi, K. Azalee Bostroem, John Debes, Justin Ely, Philip Hodge, Gerard Kriss, Derck Massa, Cristina Oliveira, Rachel Osten, Steven Osterman, Steven Penton, Charles Proffitt, Julia Roman-Duval, Paule Sonnentrucker

Proceedings Volume 8859, 88590S (2013) https://doi.org/10.1117/12.2024708

KEYWORDS: Sensors, Microchannel plates, Ultraviolet radiation, Spectrographs, Hubble Space Telescope, Calibration, Far ultraviolet, Solar processes, Airglow, X-ray astronomy

Read Abstract +

Proceedings Article | 17 September 2012 Paper

The COS FUV channel: on-orbit performance trends and early characterization of a new detector lifetime position

David Sahnow, Alessandra Aloisi, K. Azalee Bostroem, John Debes, Julia Duval, Justin Ely, Philip Hodge, Gerard Kriss, Kevin Lindsay, Derck Massa, Cristina Oliveira, Rachel Osten, Steven Osterman, Steven Penton, Charles Proffitt, Paule Sonnentrucker, Brian York

Proceedings Volume 8443, 84434C (2012) https://doi.org/10.1117/12.926487

KEYWORDS: Sensors, Microchannel plates, Calibration, Spectrographs, Lamps, Far ultraviolet, Photons, Image segmentation, Hubble Space Telescope, Ultraviolet radiation

Read Abstract +

Proceedings Article | 16 September 2011 Paper

FUV quantum efficiency degradation of cesium iodide photocathodes caused by exposure to thermal atomic oxygen

Jason McPhate, Joshi Anne, John Bacinski, Bruce Banks, Carey Cates, Paul Christensen, Brett Cruden, Larry Dunham, Eric Graham, David Hughes, Randy Kimble, Olivia Lupie, Malcolm Niedner, Steven Osterman, Steven Penton, Charles Proffitt, Diane Pugel, Oswald Siegmund, Thomas Wheeler

Proceedings Volume 8145, 81450I (2011) https://doi.org/10.1117/12.897024

KEYWORDS: Adaptive optics, Quantum efficiency, Oxygen, Sensors, Cesium, Plasma, Contamination, Error analysis, Chemical analysis, Statistical analysis

Read Abstract +

Proceedings Article | 14 September 2011 Paper

Gain sag in the FUV detector of the Cosmic Origins Spectrograph

David Sahnow, Cristina Oliveira, Alessandra Aloisi, Philip Hodge, Derck Massa, Rachel Osten, Charles Proffitt, Azalee Bostroem, Jason McPhate, Stéphane Béland, Steven Osterman, Steven Penton

Proceedings Volume 8145, 81450Q (2011) https://doi.org/10.1117/12.893989

KEYWORDS: Sensors, Image segmentation, Microchannel plates, Airglow, Photons, Calibration, Spectrographs, Electrons, Distortion, Lamps

Read Abstract +

Proceedings Article | 11 August 2010 Paper

Monitoring of the wavelength calibration lamps for the Hubble Space Telescope

Ilaria Pascucci, Charles Proffitt, Parviz Ghavamian, David Sahnow, Cristina Oliveira, Alessandra Aloisi, Tony Keyes, Steven Penton

Proceedings Volume 7731, 77313B (2010) https://doi.org/10.1117/12.857465

KEYWORDS: Lamps, Calibration, Spectrographs, Hubble Space Telescope, Sensors, Space telescopes, Ultraviolet radiation, Carbon monoxide, Visible radiation, Target acquisition

Read Abstract +

Proceedings Article | 11 August 2010 Paper

Commissioning of the cosmic origins spectrograph on the Hubble Space Telescope: an overview of COS servicing mission observatory verification

David Sahnow, Charles Keyes, Thomas Ake, Alessandra Aloisi, Stéphane Béland, Carl Biagetti, Eric Burgh, George Chapman, Thomas Delker, Kevin France, Scott Friedman, Cynthia Froning, Parviz Ghavamian, Paul Goudfrooij, James Green, George Hartig, Philip Hodge, Daniel Lennon, Derck Massa, Jason McPhate, Sami-Matias Niemi, Cristina Oliveira, Rachel Osten, Steven Osterman, Steven Penton, Merle Reinhart, Brittany Shaw, T. Ed Smith, David Soderblom, Alan Welty, Thomas Wheeler, Brian York, Wei Zheng

Proceedings Volume 7731, 773139 (2010) https://doi.org/10.1117/12.858058

KEYWORDS: Sensors, Intelligence systems, Calibration, Target acquisition, Spectrographs, Lamps, Hubble Space Telescope, Observatories, Imaging spectroscopy, Spectroscopy

Read Abstract +

Proceedings Article | 30 July 2010 Paper

Hubble Space Telescope: Cosmic Origins Spectrograph FUV detector initial on-orbit performance

Jason McPhate, Oswald H. Siegmund, John Vallerga, David Sahnow, Thomas Ake, Steven Penton, Kevin France, Derck Massa, Steven Osterman, Stéphane Béland, Stephan McCandliss

Proceedings Volume 7732, 77322H (2010) https://doi.org/10.1117/12.858211

KEYWORDS: Sensors, Microchannel plates, Image segmentation, Signal to noise ratio, Hubble Space Telescope, Spectrographs, Spatial resolution, Carbon monoxide, Quantum efficiency, Stars

Read Abstract +

Proceedings Article | 23 July 2008 Paper

The COS calibration pipeline and verification process

Mary Elizabeth Kaiser, Philip Hodge, Charles Keyes, David Sahnow, Thomas Ake, Alessandra Aloisi, Stephane Béland, Rosa Diaz, Scott Friedman, Cynthia Froning, Parviz Ghavamian, James Green, Jason McPhate, Cristina Oliveira, Steve Osterman, Steve Penton, Brittany Shaw, Erik Wilkinson

Proceedings Volume 7014, 70146G (2008) https://doi.org/10.1117/12.790239

KEYWORDS: Calibration, Sensors, Doppler effect, Switches, Space telescopes, Lamps, Spectral calibration, Data archive systems, Data conversion, Distortion

Read Abstract +

Proceedings Article | 15 July 2008 Paper

Observations of Pt-Ne hollow cathode lamps similar to those used on the Cosmic Origins Spectrograph: spectroscopy and air testing

Gillian Nave, Craig Sansonetti, Florian Kerber, Steven Penton, Michael Rosa

Proceedings Volume 7011, 70113L (2008) https://doi.org/10.1117/12.789147

KEYWORDS: Lamps, Platinum, Spectrographs, Carbon monoxide, Calibration, Neon, Spectroscopy, Spectral calibration, Ultraviolet radiation, Space telescopes

Read Abstract +

Proceedings Article | 15 July 2008 Paper

Observations of Pt/Ne hollow cathode lamps similar to those used on the Cosmic Origins Spectrograph: photometry and vacuum testing

Steven Penton, Nathaniel Cunningham, Matthew Beasley, Steven Osterman, Florian Kerber, Gillian Nave, Craig Sansonetti, Charles Keyes, Michael Rosa

Proceedings Volume 7011, 70113M (2008) https://doi.org/10.1117/12.789406

KEYWORDS: Lamps, Calibration, Photometry, Spectrographs, Electronics, Standards development, Ultraviolet radiation, Temperature metrology, Epoxies, Space telescopes

Read Abstract +

Proceedings Article | 8 December 2003 Paper

Preliminary calibration results for the HST/cosmic origins spectrograph

Erik Wilkinson, Stephane Beland, Cynthia Froning, James Green, Steven Osterman, Steven Penton, Thomas Delker, Dennis Ebbets, Adrian Martin, Jason McPhate, John Vallerga, Scott Friedman, George Hartig, Charles Keyes, Claus Leitherer, Kenneth Sembach, David Sahnow

Proceedings Volume 5164, (2003) https://doi.org/10.1117/12.505870

KEYWORDS: Calibration, Sensors, Spectrographs, Cadmium sulfide, Spectral resolution, Lamps, Spatial resolution, Mirrors, Spectral calibration, Carbon monoxide

Read Abstract +

Proceedings Article | 24 February 2003 Paper

Obtaining science data from COS: the data calibration process

Stephane Beland, Steven Penton, Erik Wilkinson

Proceedings Volume 4854, (2003) https://doi.org/10.1117/12.459773

KEYWORDS: Sensors, Calibration, Electronics, Doppler effect, Analog electronics, Spectral calibration, Data processing, Dispersion, Spectrographs, Chemical elements

Read Abstract +

Proceedings Article | 10 December 2001 Paper

Algorithms for correcting geometric distortions in delay-line anodes

Erik Wilkinson, Steven Penton, Stephane Beland, John Vallerga, Jason McPhate, David Sahnow

Proceedings Volume 4498, (2001) https://doi.org/10.1117/12.450073

KEYWORDS: Sensors, Microchannel plates, Electronics, Analog electronics, Capacitors, Dielectrics, Signal detection, Hubble Space Telescope, Calibration, Dispersion

Read Abstract +

Proceedings Article | 10 December 2001 Paper

HST-COS far-ultraviolet detector: final ground calibration

John Vallerga, Jason McPhate, Adrian Martin, Geoffrey Gaines, Oswald Siegmund, Erik Wilkinson, Steven Penton, Stephane Beland

Proceedings Volume 4498, (2001) https://doi.org/10.1117/12.450052

KEYWORDS: Sensors, Microchannel plates, Calibration, Quantum efficiency, Spatial resolution, Spectrographs, Diodes, Hubble Space Telescope, Signal to noise ratio, Amplifiers

Read Abstract +

Showing 5 of 19 publications

View contact details

UPDATE YOUR PROFILE

Is this your profile? Update it now.

Sign into your SPIE.org account

Don’t have a profile and want one?

Create an account on SPIE.org

Keywords/Phrases

Search In:

Publication Years