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We investigate the ellipticity of the point-spread function (PSF) produced by imaging an unresolved source with a telescope, subject to the effects of atmospheric turbulence. It is important to quantify these effects in order to understand…

Astrophysics · Physics 2011-02-11 W. H. de Vries , S. S. Olivier , S. J. Asztalos , L. J. Rosenberg , K. L. Baker

Single-shot volumetric fluorescence (SVF) imaging offers a significant advantage over traditional imaging methods that require scanning across multiple axial planes as it can capture biological processes with high temporal resolution. The…

The knowledge of the exact structure of the optical system PSF enables a high-quality image reconstruction in fluorescence microscopy. Accurate PSF models account for the vector nature of light and the phase and amplitude modifications.…

I present a semiclassical analysis of a spatial-mode demultiplexing (SPADE) measurement scheme for far-field incoherent optical imaging under the effects of diffraction and photon shot noise. Building on previous results that assume two…

Optics · Physics 2018-02-28 Mankei Tsang

High-dynamic range imaging from space in the visible, aiming in particular at the detection of terrestrial exoplanets, necessitates not only the use of a coronagraph, but also of adaptive optics to correct optical defects in real time.…

Astrophysics · Physics 2008-11-26 Pascal J. Bordé , Wesley A. Traub

Ultrasound is widely used in medical diagnostics allowing for accessible and powerful imaging but suffers from resolution limitations due to diffraction and the finite aperture of the imaging system, which restricts diagnostic use. The…

Computer Vision and Pattern Recognition · Computer Science 2024-08-08 Felix Duelmer , Walter Simson , Mohammad Farid Azampour , Magdalena Wysocki , Angelos Karlas , Nassir Navab

We describe the time- and position-dependent point spread function (PSF) variation of the Wide Field Channel (WFC) of the Advanced Camera for Surveys (ACS) with the principal component analysis (PCA) technique. The time-dependent change is…

Astrophysics · Physics 2009-11-13 M. J. Jee , J. P. Blakeslee , M. Sirianni , A. R. Martel , R. L. White , H. C. Ford

Point-spread-function (PSF) engineering is a powerful computational imaging techniques wherein a custom phase mask is integrated into an optical system to encode additional information into captured images. Used in combination with deep…

Computer Vision and Pattern Recognition · Computer Science 2023-03-31 Sachin Shah , Sakshum Kulshrestha , Christopher A. Metzler

(abridged) Imaging observations are generally affected by a fluctuating background of speckles, a particular problem when detecting faint stellar companions at small angular separations. Knowing the distribution of the speckle intensities…

Astrophysics · Physics 2009-11-13 Michael P. Fitzgerald , James R. Graham

The point-spread function (PSF) of an imaging system describes the response of the system to a point source. Accurately determining the PSF enables one to correct for the combined effects of focussing and scattering within the imaging…

Instrumentation and Methods for Astrophysics · Physics 2022-11-01 Stefan Johann Hofmeister , Michael Hahn , Daniel Wolf Savin

Point spread function (PSF) reconstruction (PSF-R) is a well established technique to determine reliably and accurately the PSF from Adaptive Optics (AO) control loop data. We have successfully applied this technique to improve the…

Instrumentation and Methods for Astrophysics · Physics 2020-04-15 Olivier Beltramo-Martin , Antonino Marasco , Thierry Fusco , Davide Massari , Julien Milli , Giuliana Fiorentino , B. Neichel

Instrumental aberrations strongly limit high-contrast imaging of exoplanets, especially when they produce quasistatic speckles in the science images. With the help of recent advances in deep learning, we have developed in previous works an…

Instrumentation and Methods for Astrophysics · Physics 2022-11-14 Maxime Quesnel , Gilles Orban de Xivry , Olivier Absil , Gilles Louppe

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

We present an algorithm to derive difference images for data taken with the JWST with matched point-spread functions (PSFs). It is based on the saccadic fast Fourier transform (SFFT) method but with revisions to accommodate the rotations…

Instrumentation and Methods for Astrophysics · Physics 2024-04-30 Lei Hu , Lifan Wang

Phase screens above a telescope pupil represent the variation of the phase of the electromagnetic field induced by atmospheric turbulence. Instances drawn from such statistics are represented by a vector of random phase amplitudes which are…

Astrophysics · Physics 2009-10-23 Richard J. Mathar

We present a new method of removing PSF artifacts and improving the resolution of multidimensional data sources including imagers and spectrographs. Rather than deconvolution, which is translationally invariant, this method is based on…

Starlight subtraction algorithms based on the method of Karhunen-Lo\`eve eigenimages have proved invaluable to exoplanet direct imaging. However, they scale poorly in runtime when paired with differential imaging techniques. In such…

Instrumentation and Methods for Astrophysics · Physics 2021-01-29 Joseph D. Long , Jared R. Males

Context: in astronomy, observing large fractions of the sky within a reasonable amount of time implies using large field-of-view (fov) optical instruments that typically have a spatially varying Point Spread Function (PSF). Depending on the…

Computer Vision and Pattern Recognition · Computer Science 2017-03-20 F. M. Ngolè Mboula , J. -L. Starck

We propose an alternative method to generate samples of a spatially correlated random field with applications to large-scale problems for forward propagation of uncertainty. A classical approach for generating these samples is the…

Numerical Analysis · Mathematics 2017-03-27 Sarah Osborn , Panayot Vassilevski , Umberto Villa

Ultrasound imaging systems rely on accurate point spread function (PSF) estimation to support advanced image quality enhancement techniques such as deconvolution and speckle reduction. Phase aberration, caused by sound speed inhomogeneity…

Signal Processing · Electrical Eng. & Systems 2025-02-24 Wei-Hsiang Shen , Yu-An Lin , Meng-Lin Li