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X-ray mirrors with high focusing performances are in use in both mirror modules for X-ray telescopes and in synchrotron and FEL (Free Electron Laser) beamlines. A degradation of the focus sharpness arises in general from geometrical…

Optics · Physics 2013-04-05 D. Spiga , L. Raimondi , C. Svetina , M. Zangrando

At the University of California's Lick Observatory, we have implemented an on-sky testbed for next-generation adaptive optics (AO) technologies. The Visible-Light Laser Guidestar Experiments instrument (ViLLaGEs) includes visible-light AO,…

Instrumentation and Methods for Astrophysics · Physics 2015-05-19 Katie Morzinski , Luke C. Johnson , Donald T. Gavel , Bryant Grigsby , Daren Dillon , Marc Reinig , Bruce A. Macintosh

Compressed sensing Synthetic Aperture Radar (SAR) image formation, formulated as an inverse problem and solved with traditional iterative optimization methods can be very computationally expensive. We investigate the use of denoising…

Image and Video Processing · Electrical Eng. & Systems 2025-04-25 Odysseas Pappas , Perla Mayo , Andrew Austin , Alin Achim

The development of small-angle scattering tensor tomography has enabled the study of anisotropic nanostructures in a volume-resolved manner. It is of great value to have reconstruction methods that can handle many different nanostructural…

Materials Science · Physics 2024-03-22 Leonard C. Nielsen , Paul Erhart , Manuel Guizar-Sicairos , Marianne Liebi

There are different techniques to sense the wavefront phase-distortions due to atmospheric turbulence. Curvature sensors are practical in their sensitivity being adjustable to the prevailing atmospheric conditions. Even at the best sites,…

Instrumentation and Methods for Astrophysics · Physics 2015-05-19 Aglae Kellerer , Mark Chun , Christ Ftaclas

An inverse problem in spectroscopy is considered. The objective is to restore the discrete spectrum from observed spectrum data, taking into account the spectrometer's line spread function. The problem is reduced to solution of a system of…

Numerical Analysis · Mathematics 2017-01-23 Valery Sizikov , Denis Sidorov

Adaptive optics can be used to mitigate the effects of atmospheric turbulence on imaging systems, but the correction is only partial, and deconvolution is often required to improve the resolution. This results in entire optical/digital…

Instrumentation and Methods for Astrophysics · Physics 2026-02-09 Florian Cheyssial , Laurent Mugnier , Cyril Petit

Adaptive optics systems are usually prototyped in a convenient but slow language like MATLAB or Python, and then re-written from scratch using high-performance C/C++ to perform real-time control. This duplication of effort adds costs and…

Instrumentation and Methods for Astrophysics · Physics 2024-07-11 William Thompson , Darryl Gamroth , Christian Marois , Olivier Lardière

We present a novel automatic adaptive aperture photometry algorithm for measuring the total magnitudes of merging galaxies with irregular shapes. First, we use a morphological pattern recognition routine for identifying the shape of an…

Instrumentation and Methods for Astrophysics · Physics 2017-02-08 Jen-Chao Huang , Chorng-Yuan Hwang

Statistical mechanics of spin glasses is one of the main strands toward a comprehension of information processing by neural networks and learning machines. Tackling this approach, at the fairly standard replica symmetric level of…

Disordered Systems and Neural Networks · Physics 2023-12-18 Linda Albanese , Andrea Alessandrelli , Alessia Annibale , Adriano Barra

The spectral transformation Lanczos method for the sparse symmetric definite generalized eigenvalue problem for matrices $A$ and $B$ is an iterative method that addresses the case of semidefinite or ill conditioned $B$ using a shifted and…

Numerical Analysis · Mathematics 2024-11-07 Michael Stewart

The aberrations induced by the sample and/or by the sample holder limit the resolution of optical microscopes. Wavefront correction can be achieved using a deformable mirror with wavefront sensorless optimization algorithms but, despite the…

(abridged) Extreme adaptive optics (XAO) encounters severe difficulties to cope with the high speed (>1kHz), high accuracy and high order requirements for future extremely large telescopes. An innovative high order adaptive optics system…

Instrumentation and Methods for Astrophysics · Physics 2015-09-29 Christian Delacroix , Maud Langlois , Magali Loupias , Eric Thiébaut , Louisa Adjali , Jonathan Leger , Michel Tallon

Metasurfaces allow tailored control over electromagnetic wavefronts. However, due to the local conservation of power flow, a passive, lossless, and reflectionless metasurface is limited to imparting phase discontinuities -- and not power…

Optics · Physics 2019-03-27 Brian O. Raeker , Anthony Grbic

Recently, learned image compression methods have developed rapidly and exhibited excellent rate-distortion performance when compared to traditional standards, such as JPEG, JPEG2000 and BPG. However, the learning-based methods suffer from…

Image and Video Processing · Electrical Eng. & Systems 2022-06-24 Bowen Li , Yao Xin , Youneng Bao , Fanyang Meng , Yongsheng Liang , Wen Tan

We present an analytical approach for describing spectrally constrained maximum entropy ensembles of finitely connected regular loopy graphs, valid in the regime of weak loop-loop interactions. We derive an expression for the leading two…

Disordered Systems and Neural Networks · Physics 2020-02-19 Fabian Aguirre Lopez , Anthony CC Coolen

The performance of a wide-field adaptive optics system depends on input design parameters. Here we investigate the performance of a multi-conjugate adaptive optics system design for the European Extremely Large Telescope, using an…

Instrumentation and Methods for Astrophysics · Physics 2015-09-16 Alastair Basden

The computational complexity of simultaneous inference methods in high-dimensional linear regression models quickly increases with the number variables. This paper proposes a computationally efficient method based on the Moore-Penrose…

Statistics Theory · Mathematics 2021-02-02 Tom Boot , Didier Nibbering

Achieving high-precision light manipulation is crucial for delivering information through complex media with high fidelity. However, existing spatial light modulation devices face a fundamental tradeoff between speed and accuracy. Digital…

Optics · Physics 2026-03-16 Li-Yu Yu , Sixian You

The Large Synoptic Survey Telescope (LSST) will use an active optics system (AOS) to maintain alignment and surface figure on its three large mirrors. Corrective actions fed to the LSST AOS are determined from information derived from 4…

Instrumentation and Methods for Astrophysics · Physics 2015-10-26 Bo Xin , Chuck Claver , Ming Liang , Srinivasan Chandrasekharan , George Angeli , Ian Shipsey
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