Results 261 to 270 of about 47,664 (300)

Speckle Interferometry And Differential Speckle Interferometry Using Cross-Spectrum Techniques

Optical Engineering, 1986
A cross-spectrum analysis technique that makes it possible to compute an unbiased estimate of the speckle pattern Wiener spectrum has been developed at the University of Nice. Using a one-dimensional interferometer, the technique has given results on several subjects such as the study of atmospheric modulation transfer function, including anisotropy ...
Claude Aime, Roumain G. Petrov, Francois Martin, Gilbert Ricort, Julien Borgnino   +4 more
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Differential interferometry for studying hypersonic flows

Experiments in Fluids, 1996
The purpose of this article is to describe an optical technique based on differential interferometry with strongly phase-shifted beams using a white light source and a Wollaston prism. This technique is recommonded particularly for measuring very small index variations.
J. M. Desse, E. Fabre
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Electron density measurement by differential interferometry

Review of Scientific Instruments, 2006
A novel differential interferometer is being developed to measure the electron density gradient and its fluctuations. Two separate laser beams with slight spatial offset and frequency difference are coupled into a single mixer making a heterodyne measurement of the phase difference which is <1% of the total phase change experienced by each beam ...
W. X. Ding, D. L. Brower, B. H. Deng, T. Yates   +3 more
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Differential adaptive optics for astronomical interferometry

Applied Optics, 1991
Sometimes it suffices to make the wave-front distortions across individual telescopes equal rather than zero. This leads to the concept of differential adaptive optics.
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Differential path considerations in optical stellar interferometry

Applied Optics, 1995
A formulation of the differential-air-path problem for a large-baseline optical interferometer is presented. Because air is a dispersive medium, each wavelength has a different optical path length. This can be corrected to a large extent if an extra piece of glass is placed in each arm of the interferometer.
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Approximation Eerror in Differential SAR Interferometry

IGARSS 2008 - 2008 IEEE International Geoscience and Remote Sensing Symposium, 2008
Two approximations are used in "Three-pass" D-InSAR (Differential SAR Interferometry). First, in this paper, the error caused by the approximations is deduced and defined as First-order Approximation Error. Then, the characteristics of First-order Approximation Error are discussed in theory and proved by two experiments.
Xilong Sun, Anxi Yu, Bin Cai, Diannong Liang   +3 more
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Differential interferometry with a complex contrast

Optics Communications, 2002
Abstract We present a new design of the Nomarski interferometer, which can measure displacements of several microns, with a resolution better than 10 −13 m / Hz . In the standard design this sensitivity can be achieved only within a 100 nm displacement range.
Bellon, Ludovic, Ciliberto, Sergio, Boubaker, Hatem, Guyon, Laurent   +3 more
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Experimental analysis of differential SAR interferometry

IEEE 1999 International Geoscience and Remote Sensing Symposium. IGARSS'99 (Cat. No.99CH36293), 2003
Experiments for differential interferometry were conducted over 16 months using corner reflectors. Baseline analysis based on the ephemeris data shows possible 17 pairs of good quality. Analysis of the first pair demonstrates a capability of detecting displacement with accuracy less than 1 cm.
H. Kimura, H. Kinoshita, T. Ohishi, M. Kawai, M. Tokuda   +4 more
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Using differential phases in optical interferometry

SPIE Proceedings, 2006
We present the results of differential phase experiments done with data from the Navy Prototype Optical Interferometer (NPOI). We take advantage of the fact that this instrument simultaneously records 16 spectral channels in the wavelength range 550-850nm, for multiple baselines.
Henrique R. Schmitt, Thomas A. Pauls, Christopher Tycner, J. Thomas Armstrong, James A. Benson, James H. Clark, Robert B. Hindsley, Donald J. Hutter, Deane M. Peterson, Anders M. Jorgensen, David Mozurkewich, G. Charmaine Gilbreath, Robert T. Zavala   +12 more
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Rapid, differential microthermometry using Zeeman interferometry

Applied Physics Letters, 1989
Zeeman interferometry, based on the two-frequency Zeeman effect laser, can be used for simple, noncontact differential thermometry. The thermometry is differential in both space and time. Small (0.73 μℓ ) laser-heated volumes were monitored with a Zeeman interferometer.
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