Prof. James P. Lloyd Profile

Prof. James P. Lloyd

Associate Professor at Cornell Univ

SPIE Involvement:

Author

Publications (39)

Proceedings Article | 23 August 2024 Poster + Paper

Poster + Paper

A SmallSat mission study for STARLITE: superluminous tomographic atmospheric reconstruction with laser-beacons for imaging terrestrial exoplanets

Adam Johnson, Ashley Padres, Ryan Hughes, Carmine Buonagura, Zane Chapman, Alexia Kubas, Veronica Hegelein, Ishan Mishra, Adler Smith, Abu Taqui Md Tahsin, Akshiti Parashar, Rafid Bendimerad, Deemo Chen, Qizhi Lu, Asterios Aidan Kounios, Devin Desilva, Verena Padres, Jamie Lloyd, Dmitry Savransky, Joshua Umansky-Castro, Andrew van Paridon, Elaine Petro

Proceedings Volume 13092, 130922U (2024) https://doi.org/10.1117/12.3018042

KEYWORDS: Exoplanets, Stars, Satellites, Global Positioning System, Telescopes, Design, Windows, Earth atmosphere, Adaptive optics, Laser guide stars

Read Abstract +

Proceedings Article | 26 August 2022 Presentation + Paper

Presentation + Paper

Origins and design of the Aperture Masking Interferometer on JWST

Peter Tuthill, Anand Sivaramakrishnan, James Lloyd

Proceedings Volume 12183, 121830Q (2022) https://doi.org/10.1117/12.2635818

KEYWORDS: Planets, Exoplanets, James Webb Space Telescope, Stars, Interferometers, Data modeling, Interferometry, Atmospheric modeling, Atmospheric physics, Telescopes

Read Abstract +

Proceedings Article | 1 September 2017 Paper

Paper

Optimization of high-inclination orbits using planetary flybys for a zodiacal light-imaging mission

Gabriel Soto, James Lloyd, Dmitry Savransky, Keith Grogan, Amlan Sinha

Proceedings Volume 10400, 104001X (2017) https://doi.org/10.1117/12.2274069

KEYWORDS: Exoplanets, Solar system, Algorithm development, Mechanics, Light, Light scattering, Pollution control, Space operations, Cameras, Detection and tracking algorithms

Read Abstract +

SPIE Journal Paper | 2 December 2016 Open Access

Open Access

High-resolution broadband spectroscopy using externally dispersed interferometry at the Hale telescope: part 2, photon noise theory

David Erskine, Jerry Edelstein, Edward Wishnow, Martin Sirk, Philip Muirhead, Matthew Muterspaugh, James Lloyd

JATIS, Vol. 2, Issue 04, 045001, (December 2016) https://doi.org/10.1117/12.10.1117/1.JATIS.2.4.045001

KEYWORDS: Signal to noise ratio, Spectrographs, Interference (communication), Interferometry, Point spread functions, Interferometers, Spectroscopes, Sensors, Image resolution, Fourier transforms

Read Abstract +

High-resolution broadband spectroscopy at near-infrared (NIR) wavelengths (950 to 2450 nm) has been performed using externally dispersed interferometry (EDI) at the Hale telescope at Mt. Palomar, with the TEDI interferometer mounted within the central hole of the 200-in. primary mirror in series with the comounted TripleSpec NIR echelle spectrograph. These are the first multidelay EDI demonstrations on starlight. We demonstrated very high (10×) resolution boost and dramatic (20× or more) robustness to point spread function wavelength drifts in the native spectrograph. Data analysis, results, and instrument noise are described in a companion paper (part 1). This part 2 describes theoretical photon limited and readout noise limited behaviors, using simulated spectra and instrument model with noise added at the detector. We show that a single interferometer delay can be used to reduce the high frequency noise at the original resolution (1× boost case), and that except for delays much smaller than the native response peak half width, the fringing and nonfringing noises act uncorrelated and add in quadrature. This is due to the frequency shifting of the noise due to the heterodyning effect. We find a sum rule for the noise variance for multiple delays. The multiple delay EDI using a Gaussian distribution of exposure times has noise-to-signal ratio for photon-limited noise similar to a classical spectrograph with reduced slitwidth and reduced flux, proportional to the square root of resolution boost achieved, but without the focal spot limitation and pixel spacing Nyquist limitations. At low boost (∼1×) EDI has ∼1.4× smaller noise than conventional, and at >10× boost, EDI has ∼1.4× larger noise than conventional. Readout noise is minimized by the use of three or four steps instead of 10 of TEDI. Net noise grows as step phases change from symmetrical arrangement with wavenumber across the band. For three (or four) steps, we calculate a multiplicative bandwidth of 1.8:1 (2.3:1), sufficient to handle the visible band (400 to 700 nm, 1.8:1) and most of TripleSpec (2.6:1).

Proceedings Article | 9 August 2016 Paper

Paper

Dramatic robustness of a multiple delay dispersed interferometer to spectrograph errors: how mixing delays reduces or cancels wavelength drift

David Erskine, E. Linder, E. Wishnow, J. Edelstein, M. Sirk, P. Muirhead, J. Lloyd, A. Kim

Proceedings Volume 9908, 99085Y (2016) https://doi.org/10.1117/12.2230182

KEYWORDS: Spectrographs, Interferometers, Doppler effect, Point spread functions, Moire patterns, Fabry–Perot interferometers, Lamps, Sensors, Wavelets, Data modeling

Read Abstract +

SPIE Journal Paper | 27 May 2016 Open Access

Open Access

High-resolution broadband spectroscopy using externally dispersed interferometry at the Hale telescope: Part 1, data analysis and results

David Erskine, Jerry Edelstein, Edward Wishnow, Martin Sirk, Philip Muirhead, Matthew Muterspaugh, James Lloyd, Yuzo Ishikawa, Eliza McDonald, William Shourt, Andrew Vanderburg

JATIS, Vol. 2, Issue 02, 025004, (May 2016) https://doi.org/10.1117/12.10.1117/1.JATIS.2.2.025004

KEYWORDS: Spectrographs, Point spread functions, Stars, Fabry–Perot interferometers, Interferometry, Spectroscopes, Interferometers, Lamps, Modulation transfer functions, Wavelets

Read Abstract +

Proceedings Article | 2 August 2014 Paper

Paper

Advances in stellar imaging with occultations from the CASSINI spacecraft

Paul Stewart, Peter Tuthill, Phillip Nicholson, Matthew Hedman, James Lloyd

Proceedings Volume 9143, 91431G (2014) https://doi.org/10.1117/12.2055631

KEYWORDS: Stars, Space operations, Data modeling, Tomography, Reconstruction algorithms, Saturn, Signal to noise ratio, Image resolution, Atmospheric modeling, Spectrographs

Read Abstract +

Proceedings Article | 21 September 2012 Paper

Paper

Non-redundant Aperture Masking Interferometry (AMI) and segment phasing with JWST-NIRISS

Anand Sivaramakrishnan, David Lafrenière, K. E. Saavik Ford, Barry McKernan, Anthony Cheetham, Alexandra Greenbaum, Peter Tuthill, James Lloyd, Michael Ireland, René Doyon, Mathilde Beaulieu, André Martel, Anton Koekemoer, Frantz Martinache, Peter Teuben

Proceedings Volume 8442, 84422S (2012) https://doi.org/10.1117/12.925565

KEYWORDS: James Webb Space Telescope, Visibility, Interferometry, Space telescopes, Sensors, Calibration, Telescopes, Mirrors, Wavefronts, Image segmentation

Read Abstract +

The Aperture Masked Interferometry (AMI) mode on JWST-NIRISS is implemented as a 7-hole, 15% throughput, non-redundant mask (NRM) that operates with 5-8% bandwidth filters at 3.8, 4.3, and 4.8 microns. We present refined estimates of AMI's expected point-source contrast, using realizations of noise matched to JWST pointing requirements, NIRISS detector noise, and Rev-V JWST wavefront error models for the telescope and instrument. We describe our point-source binary data reduction algorithm, which we use as a standardized method to compare different observational strategies. For a 7.5 magnitude star we report a 10-a detection at between 8.7 and 9.2 magnitudes of contrast between 100 mas to 400 mas respectively, using closure phases and squared visibilities in the absence of bad pixels, but with various other noise sources. With 3% of the pixels unusable, the expected contrast drops by about 0.5 magnitudes. AMI should be able to reach targets as bright as M=5. There will be significant overlap between Gemini-GPI and ESO-SPHERE targets and AMI's search space, and a complementarity with NIRCam's coronagraph. We also illustrate synthesis imaging with AMI, demonstrating an imaging dynamic range of 25 at 100 mas scales. We tailor existing radio interferometric methods to retrieve a faint bar across a bright nucleus, and explain the similarities to synthesis imaging at radio wavelengths. Modest contrast observations of dusty accretion flows around AGNs will be feasible for NIRISS AMI. We show our early results of image-plane deconvolution as well. Finally, we report progress on an NRM-inspired approach to mitigate mission-level risk associated with JWST's specialized wavefront sensing hardware. By combining narrow band and medium band Nyquist-sampled images taken with a science camera we can sense JWST primary mirror segment tip-tilt to lOmas, and piston to a few nm. We can sense inter-segment piston errors of up to 5 coherence lengths of the broadest bandpass filter used ( 250-500 0m depending on the filters). Our approach scales well with an increasing number of segments, which makes it relevant for future segmented-primary space missions.

Proceedings Article | 12 September 2012 Paper

Paper

Aperture mask interferometry with an integral field spectrograph

Neil Zimmerman, Anand Sivaramakrishnan, David Bernat, Ben Oppenheimer, Sasha Hinkley, James Lloyd, Peter Tuthill, Douglas Brenner, Ian Parry, Michal Simon, John Krist, Laurent Pueyo

Proceedings Volume 8445, 84452G (2012) https://doi.org/10.1117/12.926204

KEYWORDS: Stars, Adaptive optics, Calibration, Iterated function systems, Telescopes, Spectrographs, Interferometry, Space telescopes, Coronagraphy, Spectroscopy

Read Abstract +

Proceedings Article | 15 September 2011 Paper

Paper

Ten-fold spectral resolution boosting using TEDI at the Mt. Palomar NIR Triplespec spectrograph

David Erskine, J. Edelstein, P. Muirhead, M. Muterspaugh, K. Covey, D. Mondo, A. Vanderburg, P. Andelson, D. Kimber, M. Sirk, J. Lloyd

Proceedings Volume 8146, 81460M (2011) https://doi.org/10.1117/12.892664

KEYWORDS: Spectrographs, Interferometers, Modulation transfer functions, Intelligence systems, Fourier transforms, Spectral resolution, Data modeling, Interferometry, Doppler effect, Spectroscopy

Read Abstract +

Proceedings Article | 11 August 2010 Paper

Paper

Planetary system and star formation science with non-redundant masking on JWST

Anand Sivaramakrishnan, David Lafrenière, Peter Tuthill, Michael Ireland, James Lloyd, Frantz Martinache, Russell Makidon, Rémi Soummer, René Doyon, Mathilde Beaulieu, Sébastien Parmentier, Charles Beichman

Proceedings Volume 7731, 77313W (2010) https://doi.org/10.1117/12.858161

KEYWORDS: James Webb Space Telescope, Stars, Space telescopes, Visibility, Sensors, Planets, Telescopes, Calibration, Point spread functions, Wavefronts

Read Abstract +

Proceedings Article | 21 July 2010 Paper

Paper

Infrared radial velocimetry with TEDI: performance development

Jerry Edelstein, Philip Muirhead, Jason Wright, Kevin Covey, David Erskine, Matthew Muterspaugh, James Lloyd, Samuel Halverson, Mario Marckwordt, Daniel Mondo

Proceedings Volume 7735, 773583 (2010) https://doi.org/10.1117/12.858312

KEYWORDS: Interferometers, Telescopes, Optical fibers, Spectrographs, Dispersion, Stars, Mirrors, Infrared radiation, Target acquisition, Interferometry

Read Abstract +

Proceedings Article | 21 July 2010 Paper

Paper

Precise infrared radial velocimetry with the Triplespec Exoplanet Discovery Instrument: current performance and results

Philip Muirhead, Jerry Edelstein, Jason Wright, David Erskine, Matthew Muterspaugh, Kevin Covey, Mario Marckwordt, Samuel Halverson, Daniel Mondo, James Lloyd

Proceedings Volume 7735, 77357X (2010) https://doi.org/10.1117/12.857196

KEYWORDS: Interferometers, Stars, Doppler effect, Exoplanets, Spectrographs, Telescopes, Modulation, Krypton, Velocity measurements, Device simulation

Read Abstract +

Proceedings Article | 20 August 2009 Paper

Paper

Planetary system and star formation science with non-redundant masking on JWST

Anand Sivaramakrishnan, Peter Tuthill, Michael Ireland, James Lloyd, Frantz Martinache, Rémi Soummer, Russell Makidon, René Doyon, Mathilde Beaulieu, Charles Beichman

Proceedings Volume 7440, 74400Y (2009) https://doi.org/10.1117/12.826633

KEYWORDS: James Webb Space Telescope, Space telescopes, Stars, Wavefronts, Point spread functions, Coronagraphy, Telescopes, Sensors, Calibration, Mirrors

Read Abstract +

Proceedings Article | 9 July 2008 Paper

Paper

The performance of TripleSpec at Palomar

Terry Herter, Charles Henderson, John Wilson, Keith Matthews, Gustavo Rahmer, Marco Bonati, Philip Muirhead, Joseph Adams, James Lloyd, Michael Skrutskie, Dae-Sik Moon, Stephen Parshley, Matthew Nelson, Frantz Martinache, George Gull

Proceedings Volume 7014, 70140X (2008) https://doi.org/10.1117/12.789660

KEYWORDS: Telescopes, Spectrographs, Mirrors, Prisms, Space telescopes, Stars, Sensors, Cameras, Spectral resolution, Observatories

Read Abstract +

Proceedings Article | 9 July 2008 Paper

Paper

Dispersed interferometry for infrared exoplanet velocimetry

Jerry Edelstein, Matthew Muterspaugh, David Erskine, Mario Marckwordt, W. Michael Feuerstein, Tony Mercer, Agnieszka Czeszumska, Jaclyn Schwer, Sam Halverson, James Lloyd, Philip Muirhead, Jason Wright, Terry Herter

Proceedings Volume 7014, 70147F (2008) https://doi.org/10.1117/12.790315

KEYWORDS: Stars, Planets, Spectrographs, Interferometry, Exoplanets, Doppler effect, Velocity measurements, Velocimetry, Infrared radiation, Interferometers

Read Abstract +

Proceedings Article | 4 October 2007 Paper

Paper

TEDI: the TripleSpec Exoplanet Discovery Instrument

Jerry Edelstein, Matthew Ward Muterspaugh, David Erskine, W. Michael Feuerstein, Mario Marckwordt, Ed Wishnow, James Lloyd, Terry Herter, Phillip Muirhead, George Gull, Charles Henderson, Stephen Parshley

Proceedings Volume 6693, 66930W (2007) https://doi.org/10.1117/12.735474

KEYWORDS: Spectrographs, Stars, Interferometers, Absorption, Telescopes, Doppler effect, Exoplanets, Planets, Calibration, Mirrors

Read Abstract +

Proceedings Article | 6 July 2006 Paper

Paper

Instrumentation for the CCAT Telescope

G. Stacey, S. Golwala, C. Bradford, C. Dowell, G. Cortes-Medellin, T. Nikola, J. Zmuidzinas, T. Herter, S. Radford, J. Lloyd, A. Blain, R. Brown, D. Campbell, R. Giovanelli, P. Goldsmith, P. Harvey, C. Henderson, W. Langer, T. Phillips, A. C. S. Readhead, D. Woody

Proceedings Volume 6275, 62751G (2006) https://doi.org/10.1117/12.672176

KEYWORDS: Cameras, Sensors, Telescopes, Spectrometers, Multiplexing, Receivers, Bolometers, Antennas, Mirrors, Polarization

Read Abstract +

Proceedings Article | 30 June 2006 Paper

Paper

Noise studies of externally dispersed interferometry for Doppler velocimetry

David Erskine, Jerry Edelstein, James Lloyd, Philip Muirhead

Proceedings Volume 6269, 62692P (2006) https://doi.org/10.1117/12.670683

KEYWORDS: Doppler effect, Spectrographs, Interferometers, Signal to noise ratio, Velocimetry, Signal detection, Fourier transforms, Solids, Sensors, Heterodyning

Read Abstract +

Proceedings Article | 28 June 2006 Paper

Paper

Sparse-aperture adaptive optics

Peter Tuthill, James Lloyd, Michael Ireland, Frantz Martinache, John Monnier, Henry Woodruff, Theo ten Brummelaar, Nils Turner, Charles Townes

Proceedings Volume 6272, 62723A (2006) https://doi.org/10.1117/12.672342

KEYWORDS: Adaptive optics, Calibration, Point spread functions, Modulation transfer functions, Visibility, Telescopes, Interferometry, Signal to noise ratio, Deconvolution, Binary data

Read Abstract +

Proceedings Article | 28 June 2006 Paper

Paper

The TEDI instrument for near-IR radial velocity surveys

Jerry Edelstein, David Erskine, James Lloyd, Terry Herter, Mario Marckwordt, Michael Feuerstein

Proceedings Volume 6269, 62691E (2006) https://doi.org/10.1117/12.672014

KEYWORDS: Spectrographs, Interferometers, Doppler effect, Stars, Absorption, Planets, Interferometry, Telescopes, Velocimetry, Mirrors

Read Abstract +

Proceedings Article | 15 September 2005 Paper

Paper

Externally dispersed interferometry for planetary studies

David Erskine, Jerry Edelstein, Daniel Harbeck, James Lloyd

Proceedings Volume 5905, 59050R (2005) https://doi.org/10.1117/12.617879

KEYWORDS: Spectrographs, Doppler effect, Interferometers, Stars, Planets, Absorption, Spectroscopy, Spatial frequencies, Interferometry, Signal detection

Read Abstract +

Proceedings Article | 25 October 2004 Paper

Paper

Science camera calibration for extreme adaptive optics

James Wallace, Joseph Green, Michael Shao, Mitchell Troy, James Lloyd, Bruce Macintosh

Proceedings Volume 5490, (2004) https://doi.org/10.1117/12.552362

KEYWORDS: Wavefronts, Calibration, Cameras, Coronagraphy, Sensors, Adaptive optics, Phase measurement, Sensor calibration, CCD cameras, Wavefront sensors

Read Abstract +

Proceedings Article | 25 October 2004 Paper

Paper

eXtreme Adaptive Optics Planet Imager: overview and status

Bruce Macintosh, Brian Bauman, Julia Wilhelmsen Evans, James Graham, Christopher Lockwood, Lisa Poyneer, Daren Dillon, Don Gavel, Joseph Green, James Lloyd, Russell Makidon, Scot Olivier, Dave Palmer, Marshall Perrin, Scott Severson, Andrew Sheinis, Anand Sivaramakrishnan, Gary Sommargren, Remi Soummer, Mitchell Troy, J. Kent Wallace, Edward Wishnow

Proceedings Volume 5490, (2004) https://doi.org/10.1117/12.552188

KEYWORDS: Adaptive optics, Point spread functions, Wavefronts, Planets, Coronagraphy, Wavefront sensors, Telescopes, Stars, Imaging systems, Calibration

Read Abstract +

Proceedings Article | 25 October 2004 Paper

Paper

Laser guide star adaptive optics imaging polarimetry of Herbig Ae/Be stars

Marshall Perrin, James Graham, Paul Kalas, James Lloyd, Claire Max, Donald Gavel, Deanna Pennington, Elinor Gates

Proceedings Volume 5490, (2004) https://doi.org/10.1117/12.551932

KEYWORDS: Stars, Adaptive optics, Polarization, Polarimetry, Wave plates, Laser guide stars, Telescopes, Speckle, Prisms, Point spread functions

Read Abstract +

Proceedings Article | 25 October 2004 Paper

Paper

The Lyot project: toward exoplanet imaging and spectroscopy

Ben Oppenheimer, Andrew Digby, Laura Newburgh, Douglas Brenner, Michael Shara, Jacob Mey, Charles Mandeville, Russell Makidon, Anand Sivaramakrishnan, Remi Soummer, James Graham, Paul Kalas, Marshall Perrin, Lewis Roberts, Jeffrey Kuhn, Kathryn Whitman, James Lloyd

Proceedings Volume 5490, (2004) https://doi.org/10.1117/12.552211

KEYWORDS: Imaging spectroscopy, Exoplanets, Coronagraphy, Spectroscopy, Adaptive optics, Electro optical systems, Wavefronts, Astronomy, Stars

Read Abstract +

Proceedings Article | 25 October 2004 Paper

Paper

Coronagraph design for an extreme adaptive optics system with spatially filtered wavefront sensing on segmented telescopes

Anand Sivaramakrishnan, Russell Makidon, Remi Soummer, Bruce Macintosh, Mitchell Troy, Gary Chanan, James Lloyd, Marshall Perrin, James Graham, Lisa Poyneer, Andrew Sheinis

Proceedings Volume 5490, (2004) https://doi.org/10.1117/12.551939

KEYWORDS: Coronagraphy, Point spread functions, Adaptive optics, Telescopes, Image segmentation, Space telescopes, Stars, Wavefront sensors, Fourier transforms, Wavefronts

Read Abstract +

Proceedings Article | 20 October 2004 Paper

Paper

Optical turbulence in the Antarctic atmosphere

James Lloyd

Proceedings Volume 5491, (2004) https://doi.org/10.1117/12.552226

KEYWORDS: Turbulence, Adaptive optics, Interferometry, Atmospheric optics, Astronomy, Stars, Optical turbulence, Earth's atmosphere, Atmospheric turbulence, Interferometers

Read Abstract +

Proceedings Article | 20 October 2004 Paper

Paper

The Antarctic planet interferometer

Mark Swain, Christopher Walker, Wesley Traub, John Storey, Vincent Coude du Foresto, Eric Fossat, Farrokh Vakili, Anthony Stark, James Lloyd, Peter Lawson, Adam Burrows, Michael Ireland, Rafael Millan-Gabet, Gerard van Belle, Benjamin Lane, Gautam Vasisht, Tony Travouillon

Proceedings Volume 5491, (2004) https://doi.org/10.1117/12.552221

KEYWORDS: Interferometers, Planets, Exoplanets, Infrared radiation, Stars, Interferometry, Telescopes, Surface conduction electron emitter displays, Domes, Infrared detectors

Read Abstract +

Proceedings Article | 28 September 2004 Paper

Paper

A robotic instrument for measuring high altitude atmospheric turbulence from Dome C, Antarctica

Jon Lawrence, Michael Ashley, Suze Kenyon, John Storey, Andrei Tokovinin, James Lloyd, Mark Swain

Proceedings Volume 5489, (2004) https://doi.org/10.1117/12.551017

KEYWORDS: Domes, Telescopes, Turbulence, Stars, Scintillation, Atmospheric turbulence, CCD cameras, Observatories, Mirrors, Space telescopes

Read Abstract +

Proceedings Article | 19 November 2003 Paper

Paper

Extreme adaptive optics planet imager: XAOPI

Bruce Macintosh, James Graham, Lisa Poyneer, Gary Sommargren, Julia Wilhelmsen, Don Gavel, Steve Jones, Paul Kalas, James Lloyd, Russ Makidon, Scot Olivier, Dave Palmer, Jennifer Patience, Marshall Perrin, Scott Severson, Andrew Sheinis, Anand Sivaramakrishnan, Mitch Troy, J. Wallace

Proceedings Volume 5170, (2003) https://doi.org/10.1117/12.506836

KEYWORDS: Wavefronts, Adaptive optics, Wavefront sensors, Planets, Imaging systems, Coronagraphy, Point spread functions, Stars, Telescopes, Mirrors

Read Abstract +

Proceedings Article | 19 November 2003 Paper

Paper

Extrasolar planet science with the Antarctic planet interferometer

James Lloyd, Benjamin Lane, Mark Swain, John Storey, Tony Travouillon, Wesley Traub, Christopher Walker

Proceedings Volume 5170, (2003) https://doi.org/10.1117/12.506895

KEYWORDS: Exoplanets, Earth's atmosphere, Turbulence, Planets, Interferometers, Interferometry, Atmospheric sciences, Astronomy, Humidity

Read Abstract +

Proceedings Article | 3 March 2003 Paper

Paper

The adaptive optics point-spread function at moderate and high Strehl ratios

Anand Sivaramakrishnan, Philip Hodge, Russell Makidon, Marshall Perrin, James Lloyd, Eric Bloemhof, Ben Oppenheimer

Proceedings Volume 4860, (2003) https://doi.org/10.1117/12.457668

KEYWORDS: Point spread functions, Adaptive optics, Speckle, Telescopes, Space telescopes, Modulation, Fourier transforms, Optical instrument design, Speckle pattern, Device simulation

Read Abstract +

Proceedings Article | 3 March 2003 Paper

Paper

Four-quadrant phase mask: analytical calculation and pupil geometry

James Lloyd, Donald Gavel, James Graham, Philip Hodge, Anand Sivaramakrishnan, G. Voit

Proceedings Volume 4860, (2003) https://doi.org/10.1117/12.457880

KEYWORDS: Coronagraphy, Convolution, Error analysis, Fourier transforms, Space telescopes, Telescopes, Diffraction, Image filtering, Exoplanetary science, Testing and analysis

Read Abstract +

Proceedings Article | 7 February 2003 Paper

Paper

Recent science and engineering results with the laser guide star adaptive optics system at Lick Observatory

Donald Gavel, Elinor Gates, Claire Max, Scot Olivier, Brian Bauman, Deanna Pennington, Bruce Macintosh, Jennifer Patience, Curtis Brown, Pamela Danforth, Randall Hurd, Scott Severson, James Lloyd

Proceedings Volume 4839, (2003) https://doi.org/10.1117/12.459680

KEYWORDS: Adaptive optics, Laser guide stars, Stars, Cameras, Observatories, Telescopes, Infrared cameras, K band, Diagnostics, Imaging systems

Read Abstract +

Proceedings Article | 4 February 2002 Paper

Paper

Science with laser guide stars at Lick Observatory

Donald Gavel, Claire Max, Scot Olivier, Brian Bauman, Deanna Pennington, Bruce Macintosh, Jennifer Patience, Curtis Brown, Pamela Danforth, Randall Hurd, Elinor Gates, Scott Severson, James Lloyd

Proceedings Volume 4494, (2002) https://doi.org/10.1117/12.454808

KEYWORDS: Stars, Adaptive optics, Laser guide stars, Cameras, Galactic astronomy, Telescopes, Wavefront sensors, Sensors, Observatories, K band

Read Abstract +

Proceedings Article | 27 December 2001 Paper

Paper

Astronomical coronagraphy with high-order adaptive optics systems

James Lloyd, James Graham, Paul Kalas, Ben Oppenheimer, Anand Sivaramakrishnan, Russell Makidon, Bruce Macintosh, Claire Max, Pierre Baudoz, Jeff Kuhn, Dan Potter

Proceedings Volume 4490, (2001) https://doi.org/10.1117/12.455437

KEYWORDS: Adaptive optics, Coronagraphy, Stars, Astronomy, Mirrors, Space telescopes, Telescopes, Imaging systems, Planets, Surveillance systems

Read Abstract +

Proceedings Article | 16 August 2000 Paper

Paper

IRCAL: the infrared camera for adaptive optics at Lick Observatory

James Lloyd, Michael Liu, Bruce Macintosh, Scott Severson, William Deich, James Graham

Proceedings Volume 4008, (2000) https://doi.org/10.1117/12.395540

KEYWORDS: Adaptive optics, Telescopes, Sensors, Cameras, Imaging systems, Observatories, Infrared cameras, Human-machine interfaces, Diffraction, Mirrors

Read Abstract +

Proceedings Article | 8 September 1995 Paper

Paper

Near-infrared sky brightness monitor for the South Pole

Michael Ashley, Michael Burton, James Lloyd, John Storey

Proceedings Volume 2552, (1995) https://doi.org/10.1117/12.218239

KEYWORDS: Computing systems, Sensors, Mirrors, Observatories, Nitrogen, Lamps, Calibration, Astronomy, Diodes, Satellites

Read Abstract +

Showing 5 of 39 publications

SIGN IN TO:

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

Advertisement

Advertisement