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Related papers: Speckle Statistics in Adaptively Corrected Images

200 papers

We develop a general method for customizing the intensity statistics of speckle patterns on a target plane. By judiciously modulating the phase-front of a monochromatic laser beam, we experimentally generate speckle patterns with…

Optics · Physics 2019-03-12 Nicholas Bender , Hasan Yilmaz , Yaron Bromberg , Hui Cao

We study the fluctuations of the light emitted by two identical incoherent point sources in a disordered environment. The intensity-intensity correlation function and the speckle contrast, obtained after proper temporal and configurational…

Optics · Physics 2015-02-09 R. Carminati , G. Cwilich , L. S. Froufe-Pérez , J. J. Sáenz

Quasi-static speckles are a current limitation to faint companion imaging of bright stars. Here we show through simulation and theory that an adaptive pupil mask can be used to reduce these speckles and increase the visibility of faint…

Instrumentation and Methods for Astrophysics · Physics 2015-06-05 James Osborn

The method of location and spectral estimation of weak signals on a noise background is being considered. The method is based on the optimized on order and noise dispersion autoregressive model of a sought signal. A new approach of model…

Computational Engineering, Finance, and Science · Computer Science 2007-07-03 Yu. Bunyak , O. Bunyak

Statistical processing of speckle data enables observation of speed of processes. In intensity-based pointwise dynamic speckle analysis, a map related to speed's spatial distribution is extracted from a sequence of speckle patterns formed…

Image and Video Processing · Electrical Eng. & Systems 2023-03-15 Elena Stoykova , Blaga Blagoeva , Natalya Berberova-Buhova , Mikhail Levchenko , Dimana Nazarova , Lian Nedelchev , Joongki Park

The major noise source limiting high-contrast imaging is due to the presence of quasi-static speckles. Speckle noise originates from wavefront errors caused by various independent sources, and it evolves on different timescales pending to…

Instrumentation and Methods for Astrophysics · Physics 2015-06-04 P. Martinez , C. Loose , E. Aller Carpentier , M. Kasper

Random light fields -- commonly known as speckles -- demonstrate Rayleigh intensity statistics and only possess local correlations: which occur within the individual speckle grains. In this work, we develop an experimental method for…

Optics · Physics 2019-11-15 Nicholas Bender , Hasan Yılmaz , Yaron Bromberg , Hui Cao

This article begins with the discussions on the formation of speckles in the case of non-coherent quasi monochromatic source and of ways to detect them. Prior to this, a brief introduction on the behavior of the atmosphere and its effect on…

Astrophysics · Physics 2007-05-23 Swapan K. Saha

The useful dynamic range of an image in the diffraction limited regime is usually limited by speckles caused by residual phase errors in the optical system forming the image. The technique of speckle decorrelation involves introducing many…

Astrophysics · Physics 2007-05-23 Anand Sivaramakrishnan , James P. Lloyd , Philip E. Hodge , Bruce A. Macintosh

Speckle Noise is the dominant source of error in high contrast imaging with adaptive optics system. We discuss the potential for wavefront sensing telemetry to calibrate speckle noise with sufficient precision and accuracy so that it can be…

The new technique of Speckle Stabilization has great potential to provide optical imaging data at the highest angular resolutions from the ground. While Speckle Stabilization was initially conceived for integral field spectroscopic…

Instrumentation and Methods for Astrophysics · Physics 2015-05-20 M. Keremedjiev , S. S. Eikenberry

Even though the technology of adaptive optics (AO) is rapidly maturing, calibration of the resulting images remains a major challenge. The AO point-spread function (PSF) changes quickly both in time and position on the sky. In a typical…

Astrometric precision and knowledge of the point spread function are key ingredients for a wide range of astrophysical studies including time-delay cosmography in which strongly lensed quasar systems are used to determine the Hubble…

Instrumentation and Methods for Astrophysics · Physics 2021-09-22 Geoff C. -F. Chen , Tommaso Treu , Christopher D. Fassnacht , Sam Ragland , Thomas Schmidt , Sherry H. Suyu

This paper provides a framework for the incorporation of the wavefront sensor measurements in the context of observing modes in which the science camera takes millisecond exposures. In this formulation, the wavefront sensor measurements…

Instrumentation and Methods for Astrophysics · Physics 2015-06-12 Richard A. Frazin

With the availability of thousands of type Ia supernovae in the near future the magnitude scatter induced by lensing will become a major issue as it affects parameter estimation. Current N-body simulations are too time consuming to be…

Cosmology and Nongalactic Astrophysics · Physics 2013-09-10 Valerio Marra , Miguel Quartin , Luca Amendola

We present a method for speckle holography that is optimised for crowded fields. Its two key features are an iterativ improvement of the instantaneous Point Spread Functions (PSFs) extracted from each speckle frame and the (optional)…

Instrumentation and Methods for Astrophysics · Physics 2015-05-30 R. Schoedel , S. Yelda , A. Ghez , J. H. V. Girard , L. Labadie , R. Rebolo , A. Perez-Garrido , M. R. Morris

This work is concerned with optical imaging in strongly diffusive environments. We consider a typical setting in optical coherence tomography where a sample is probed by a collection of wavefields produced by a laser and propagating through…

Optics · Physics 2024-12-10 Randy Bartels , Olivier Pinaud , Maxine Varughese

We present integrated optical spectrophotometry for a sample of 417 nearby galaxies. Our observations consist of spatially integrated, S/N=10-100 spectroscopy between 3600 and 6900 Angstroms at ~8 Angstroms FWHM resolution. In addition, we…

Astrophysics · Physics 2009-11-11 John Moustakas , Robert C. Kennicutt

A comprehensive new approach is presented for deriving probability densities of physical properties characterizing lens or source that constitute an observed galactic microlensing event. While previously encountered problems are overcome,…

Astrophysics · Physics 2009-11-11 M. Dominik

High dynamic-range imagers aim to block out or null light from a very bright primary star to make it possible to detect and measure far fainter companions; in real systems a small fraction of the primary light is scattered, diffracted, and…

Instrumentation and Methods for Astrophysics · Physics 2015-06-22 Rob Fergus , David W. Hogg , Rebecca Oppenheimer , Douglas Brenner , Laurent Pueyo