Mr. Jeffrey D. Barchers Profile

Jeffrey D. Barchers

President at Nutronics Inc

SPIE Involvement:

Author

Proceedings Article | 25 September 2007 Paper

Laboratory demonstration of wavefront-based stochastic parallel gradient descent adaptive optics system

Mikhail Belen'kii, Jeff Barchers, Eric Berg, Don Bruns, Deborah Fung, Richard Gallant, Clay Kirk, Hope Runyeon, Vincent Rye, Josh Voass

Proceedings Volume 6708, 67080I (2007) https://doi.org/10.1117/12.734309

KEYWORDS: Adaptive optics, Turbulence, Thermal blooming, Beam controllers, Cameras, Control systems, Aluminum, Beam splitters, Wave propagation, Dynamical systems

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A laboratory demonstration of two novel tactical beam control methods for correcting the effects of strong turbulence including Beacon Anisoplanatism, and the combined effects of Beacon Anisoplanatism and Thermal Blooming, respectively, were performed in SAIC's Tactical Beam Control Test-Bed. Both systems were tested with ratio of aperture diameter to Fried parameter, D/r₀, of up to 7, and ratio of beam spot size at the target to isoplanatic angle, θ_B/θ_o, of up to 10. The first method was implemented in a Wavefront-based Stochastic Parallel Gradient Decent (WSPGD) adaptive optics (AO) system, which uses an off-axis wavefront sensor (WFS) to provide feedback for a multi-dithering beam control algorithm. The second method was implemented in a Hybrid WSPGD AO system, which incorporates the WSPGD AO system with a conventional Phase Conjugate (PC) AO system. The Hybrid system uses an on-axis WFS to generate initial deformable mirror commands and an off-axis WFS to generate additional commands that account for the high frequency phase components removed from the wavefront of a laser return by Beacon Anisoplanatism. We developed a low speed PC-based WSPGD controller, implemented designs of the WSPGD and Hybrid WSPGD AO systems in SAIC's Test-Bed, and tested both AO systems in static and dynamic turbulence over a wide range of turbulence conditions. A target-plane tracker was used to stabilize the line-of-sight in the AO corrected beam. Test results show that the WSPGD AO system efficiently compensates the effects of Beacon Anisoplanatism for both static and dynamic turbulence, providing a mean performance gain of 1.8 averaged over multiple turbulent realizations. We also found in testing that the Hybrid WSPGD system efficiently compensates for Beacon Anisoplanatism in the presence of Thermal Blooming - providing improved compensation for both Thermal Blooming and turbulence. In the presence of strong Beacon Anisoplanatism with θ_B/θ_o of up to 10, the maximum performance gain is 4.9 and the mean performance gain for multiple turbulence realizations is 2.1.

Proceedings Article | 7 February 2003 Paper

Performance of wavefront sensors in strong scintillation

Jeffrey Barchers, David Fried, Donald Link, Glenn Tyler, William Moretti, Terry Brennan, Robert Fugate

Proceedings Volume 4839, (2003) https://doi.org/10.1117/12.457126

KEYWORDS: Sensors, Wavefront sensors, Scintillation, Shearing interferometers, Point diffraction interferometers, Turbulence, Reconstruction algorithms, Phase shifting, Phase measurement, Wave propagation

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Proceedings Article | 6 November 2002 Paper

First-order finite element model for modeling of a continuous facesheet deformable mirror

Kelsey Rogers, Jeffrey Barchers

Proceedings Volume 4825, (2002) https://doi.org/10.1117/12.454636

KEYWORDS: Actuators, Deformable mirrors, Data modeling, Finite element methods, Calibration, Sensors, Statistical modeling, Systems modeling, Error analysis, Data analysis

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Proceedings Article | 6 November 2002 Paper

Noise analysis for complex field estimation using a self-referencing interferometer wavefront sensor

Troy Rhoadarmer, Jeffrey Barchers

Proceedings Volume 4825, (2002) https://doi.org/10.1117/12.450472

KEYWORDS: Optical amplifiers, Signal to noise ratio, Wavefronts, Cameras, Phase shifting, Phase shifts, Beam splitters, Quantum efficiency, Interference (communication), Wavefront sensors

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SPIE Journal Paper | 1 September 2002

Supersampling multiframe blind deconvolution resolution enhancement of adaptive optics compensated imagery of low earth orbit satellites

David Gerwe, David Lee, Jeffrey Barchers

OE, Vol. 41, Issue 09, (September 2002) https://doi.org/10.1117/12.10.1117/1.1497615

KEYWORDS: Staring arrays, Point spread functions, Deconvolution, Image resolution, Turbulence, Adaptive optics, Telescopes, Reconstruction algorithms, Satellite imaging, Satellites

Proceedings Article | 25 June 2002 Paper

Noise gain and misregistration calculations for a two-deformable mirror-field conjugation system

Jeffrey Barchers

Proceedings Volume 4724, (2002) https://doi.org/10.1117/12.472369

KEYWORDS: Fluorescence correlation spectroscopy, Signal to noise ratio, Turbulence, Spatial frequencies, Optical simulations, Phase measurement, Wavefront sensors, Fourier transforms, Atmospheric propagation, Refractive index

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Proceedings Article | 4 February 2002 Paper

Complex field reconstruction using gradient and intensity measurements from a Shack-Hartmann wave front sensor

Troy Rhoadarmer, Jeffrey Barchers, Earl Spillar

Proceedings Volume 4494, (2002) https://doi.org/10.1117/12.454796

KEYWORDS: Reconstruction algorithms, Wavefronts, Scintillation, Adaptive optics, Wavefront sensors, Performance modeling, Algorithm development, Computer simulations, Atmospheric modeling, Atmospheric optics

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Proceedings Article | 4 February 2002 Paper

Increase in point spread function uniformity over the compensated field of view in strong scintillation using two deformable mirrors

Jeffrey Barchers

Proceedings Volume 4494, (2002) https://doi.org/10.1117/12.454785

KEYWORDS: Point spread functions, Deformable mirrors, Wavefront sensors, Scintillation, Atmospheric propagation, Turbulence, Actuators, Spatial filters, Adaptive optics, Wave propagation

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Proceedings Article | 4 February 2002 Paper

Identification of the registration of a deformable mirror to a Schack Hartmann wavefront sensor in an adaptive optical system

Jeffrey Barchers, Troy Rhoadarmer, David Lee

Proceedings Volume 4494, (2002) https://doi.org/10.1117/12.454792

KEYWORDS: Actuators, Deformable mirrors, Wavefront sensors, Image registration, Error analysis, Optical alignment, Signal to noise ratio, Sensors, Adaptive optics, Atmospheric turbulence

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Proceedings Article | 31 October 2000 Paper

Supersampling multiframe blind deconvolution resolution enhancement of adaptive-optics-compensated imagery of LEO satellites

David Gerwe, David Lee, Jeffrey Barchers

Proceedings Volume 4091, (2000) https://doi.org/10.1117/12.405776

KEYWORDS: Staring arrays, Point spread functions, Diffraction, Image resolution, Telescopes, Adaptive optics, Satellites, Satellite imaging, Deconvolution, Statistical analysis

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