Results 251 to 260 of about 3,896,846 (293)

High-contrast Coronagraphic Techniques

EAS Publications Series, 2010
The direct detection of very faint companions to bright stars requires the development of effective high-contrast detection techniques, and the past decade has seen remarkable conceptual and instrumental progress in this area. New coronagraphic and interferometric techniques are regularly being deployed for on-sky tests and observations, and extreme ...
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Nonlinear technique for the enhancement of extremely high contrast images

SPIE Proceedings, 2008
An adaptive technique for image enhancement based on a specifically designed nonlinear function is presented in this paper. The enhancement technique constitutes three main processes-adaptive intensity enhancement, contrast adjustment, and color restoration.
Numan Unaldi, Saibabu Arigela, Vijayan K. Asari, Zia-ur Rahman   +3 more
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High-contrast active cavitation imaging technique based on multiple bubble wavelet transform

The Journal of the Acoustical Society of America, 2016
In this study, a unique method that combines the ultrafast active cavitation imaging technique with multiple bubble wavelet transform (MBWT) for improving cavitation detection contrast was presented. The bubble wavelet was constructed by the modified Keller–Miksis equation that considered the mutual effect among bubbles.
Shukuan, Lu, Shanshan, Xu, Runna, Liu, Hong, Hu, Mingxi, Wan   +4 more
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Multiplicative-regularized subspace technique to solve high contrast inverse scattering problems

2016 Progress in Electromagnetic Research Symposium (PIERS), 2016
In this talk, we will propose a new optimization scheme for solving electromagnetic inverse scattering problems. In the inverse scattering problemthe physical properties of hidden targets, i.e., the permittivity and/or permeability can be retrieve from the measured scattering data excited by several incidences.
Kuiwen Xu, Yu Zhong, null Gaofeng Wang
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22.3: High‐Definition Projection Screen: Enhancing Technique of Contrast and Fineness

SID Symposium Digest of Technical Papers, 2003
Abstract A novel high‐definition rear projection screen (Blue Ocean™ screen, Nitto Jushi Kogyo, Co., Ltd.) has been developed. Uniformity of brightness and color can be achieved with no lens elements by controlling the multiple light scattering. The enhancing technique of contrast and fineness in ambient light has been demonstrated in
Takamitsu Okumura, Hiromasa Suzuki, Ahikiro Tagaya, Yasuhiro Koike, Eizaburo Higuchi   +4 more
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High contrast internal and external coronagraph masks produced by various techniques

SPIE Proceedings, 2013
Masks for high contrast internal and external coronagraphic imaging require a variety of masks depending on different architectures to suppress star light. Various fabrication technologies are required to address a wide range of needs including gradient amplitude transmission, tunable phase profiles, ultra-low reflectivity, precise small scale features,
Kunjithapatham Balasubramanian, Daniel Wilson, Victor White, Richard Muller, Matthew Dickie, Karl Yee, Ronald Ruiz, Stuart Shaklan, Eric Cady, Brian Kern, Ruslan Belikov, Olivier Guyon, N. Jeremy Kasdin   +12 more
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Adaptive optics with advanced phase-contrast techniques I High-resolution wave-front sensing

Journal of the Optical Society of America A, 2001
High-resolution phase-contrast wave-front sensors based on phase spatial light modulators and micromirror/ liquid-crystal arrays are introduced. Wave-front sensor performance is analyzed for atmospheric-turbulence-induced phase distortions described by the Kolmogorov and the Andrews models.
Vorontsov, Mikhail, Justh, Eric W., Beresnev, Leonid A.   +2 more
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Future Exoplanet Research: High-Contrast Imaging Techniques

2017
High-contrast imaging (HCI) techniques appear like the best solutions to directly characterize large orbit planets and planetary environments in the future. The first dedicated scientific instruments like SPHERE on VLT and GPI on Gemini South have only been commissioned in 2013-2014.
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Adaptive optics with advanced phase-contrast techniques II High-resolution wave-front control

Journal of the Optical Society of America A, 2001
A wave-front control paradigm based on gradient-flow optimization is analyzed. In adaptive systems with gradient-flow dynamics, the output of the wave-front sensor is used to directly control high-resolution wavefront correctors without the need for wave-front phase reconstruction (direct-control systems).
Justh, Eric W., Vorontsov, Mikhail, Carhart, Gary W., Beresnev, Leonid A., Krishnaprasad, P. S.   +4 more
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TECHNIQUE FOR SELECTIVE MICROANGIOGRAPHY OF SKIN FLAPS WITH HIGH CONTRAST AND FINE DETAIL

Journal of Reconstructive Microsurgery, 2000
The technical factors of microangiography were studied, and the authors found that the main limiting factors in resolution were the injection pressure of the contrast medium and the thickness of the materials. A gentle manual hand pressure injection, with the aid of visual monitoring under the operating microscope, were keys to obtaining beautiful ...
K, Homma, T, Sugihara, H H, Igawa, K, Ezoe, T, Fujita   +4 more
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