Results 241 to 250 of about 664,049 (296)
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Aperture fields of an array of rectangular apertures
IRE Transactions on Antennas and Propagation, 1962This paper presents a rigorous formulation of the boundary value problem posed by an electromagnetic wave incident upon a plane screen containing a doubly periodic array of rectangular apertures. The differential-integral equation method of Copson is employed to derive integral equations in the components of the aperture field.
R. Kieburtz, A. Ishimaru
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SPIE Proceedings, 2016
This paper analyzes the modulation transfer function of three sub-mirror sparse aperture optical system (Golay3) among the low contrast with the central part, the side lobe peak and the sub-mirror aperture. It is shown that the sparse aperture system can be achieved higher frequency information while the optical imaging system is designed and the side ...
Zhiyi Lu +4 more
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This paper analyzes the modulation transfer function of three sub-mirror sparse aperture optical system (Golay3) among the low contrast with the central part, the side lobe peak and the sub-mirror aperture. It is shown that the sparse aperture system can be achieved higher frequency information while the optical imaging system is designed and the side ...
Zhiyi Lu +4 more
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REACTIVE ENERGY IN APERTURE FIELDS AND APERTURE Q
Canadian Journal of Physics, 1963An analysis of the properties of a radiating aperture in an infinite conducting screen is made by expanding the field in terms of plane waves. Expressions for the far zone field, power flow, and energy stored in the reactive electric and magnetic fields are obtained. This enables the Q of the aperture to be evaluated.
Collin, R. E., Rothschild, S.
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2014
In the beginning God created the world. Waste and void, waste and void. And darkness was upon the face of the deep. And when there were men, in their various ways, they struggled in torment towards God. Blindly and vainly, for man is a vain thing, and man without God is a seed upon the wind: driven this way and that, and finding no place of lodgement ...
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In the beginning God created the world. Waste and void, waste and void. And darkness was upon the face of the deep. And when there were men, in their various ways, they struggled in torment towards God. Blindly and vainly, for man is a vain thing, and man without God is a seed upon the wind: driven this way and that, and finding no place of lodgement ...
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Optics Letters, 2008
A variable aperture has been fabricated and demonstrated using polydimethylsiloxane-based optofluidic technology. The device consists of a deformable membrane, an air pressure chamber, a cavity filled with light-absorbing liquid, and a rigid transparent upper plate.
Yu, H., Zhou, G., Chau, F.S., Lee, F.
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A variable aperture has been fabricated and demonstrated using polydimethylsiloxane-based optofluidic technology. The device consists of a deformable membrane, an air pressure chamber, a cavity filled with light-absorbing liquid, and a rigid transparent upper plate.
Yu, H., Zhou, G., Chau, F.S., Lee, F.
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Large-aperture approximation for not-so-large apertures
Optical Engineering, 2013In-flight wavefront measurements around a flat-window turret at subsonic Mach numbers are analyzed in instantaneous and time-averaged sense. In addition to the root-mean-squared levels of aero-optical distortions, higher-order spatial statistics are calculated, and their dependence as a function of the viewing angle is discussed. Given the optical data
Chris Porter +2 more
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Diffraction by an Aperture. II
Journal of Applied Physics, 1957The field diffracted by an aperture of any shape is evaluated asymptotically for small wavelengths on the basis of several approximate diffraction theories. These are the Kirchhoff method, its two customary modifications, and W. Braunbek's new modification. In each case, a double integral over the aperture is evaluated asymptotically, and contributions
Keller, Joseph B. +2 more
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Large-aperture synthetic aperture imaging ladar
Optical Engineering, 2018A strip-mode side-looking large-aperture synthetic aperture imaging ladar (SAIL) based on free-space optics is designed to experimentally verify the key performances for further airborne application. The optical difficulties in the spatial domain, including optical antenna and imaging resolution for large-aperture SAIL, are considered systematically ...
Yanan Zhi +6 more
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Physical Review E, 1995
We analyze the problem of the geometrical aperture between the two faces of a crack described as a self-affine surface. We consider the contact of the two surfaces after a relative rigid-body displacement (translation and/or rotation) of one side of the crack with respect to the opposite one.
Plouraboué, Franck +4 more
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We analyze the problem of the geometrical aperture between the two faces of a crack described as a self-affine surface. We consider the contact of the two surfaces after a relative rigid-body displacement (translation and/or rotation) of one side of the crack with respect to the opposite one.
Plouraboué, Franck +4 more
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Index class apertures—a class of flexible coded aperture
Applied Optics, 2012A class of flexible coded apertures, called index class apertures, is presented. The configurations are shown to possess similar properties to the geometric apertures of Gourlay and Stephen [Appl. Opt.22, 4042 (1983)], and it is demonstrated that the modified uniformly redundant arrays (MURAs) are a special case of the index class apertures.
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