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Related papers: Multiple spatial frequencies wavefront sensing

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Wavefront shaping is a technique for directing light through turbid media. The theoretical aspects of wavefront shaping are well understood, and under near-ideal experimental conditions, accurate predictions for the expected signal…

Optics · Physics 2024-07-01 Bahareh Mastiani , Daniël W. S. Cox , Ivo M. Vellekoop

Multivariate spatial field data are increasingly common and whose modeling typically relies on building cross-covariance functions to describe cross-process relationships. An alternative viewpoint is to model the matrix of spectral…

Statistics Theory · Mathematics 2015-05-07 William Kleiber

This is the first article in a series of three dealing with the exploitation of speckle for imaging purposes. Speckle is the complex interference wave-field produced by a random distribution of un-resolved scatterers. In this paper, we show…

Applied Physics · Physics 2026-02-06 Elsa Giraudat , Flavien Bureau , William Lambert , Mathias Fink , Alexandre Aubry

We report an extensive numerical study and supporting experimental results on the spectral characterization of optical aberrations in macroscopic fluidic lenses with tunable focal distance and aperture shape. Using a Shack-Hartmann…

Optics · Physics 2023-12-19 Graciana Puentes , Fernando Minotti

In adaptive optics, the measurement of spatial coherence length helps in deciding the optimum design parameters of a Shack Hartmann Sensor (SHS). Two methods of estimating the spatial coherence length of optical wavefronts are presented.…

Instrumentation and Methods for Astrophysics · Physics 2009-11-08 Akondi Vyas , M. B. Roopashree , B. Raghavendra Prasad

High spatial frequency information, including fine details like textures, significantly contributes to the accuracy of semantic segmentation. However, according to the Nyquist-Shannon Sampling Theorem, high-frequency components are…

Computer Vision and Pattern Recognition · Computer Science 2025-07-24 Linwei Chen , Ying Fu , Lin Gu , Dezhi Zheng , Jifeng Dai

Wavefront shaping allows for ultimate control of light propagation in multiple-scattering media by adaptive manipulation of incident waves. We shine two separate wavefront-shaped beams on a layer of dry white paint to create two enhanced…

Optics · Physics 2014-08-11 S. R. Huisman , T. J. Huisman , S. A. Goorden , A. P. Mosk , P. W. H. Pinkse

We present a single-stage casual waveform-to-waveform multichannel model that can separate moving sound sources based on their broad spatial locations in a dynamic acoustic scene. We divide the scene into two spatial regions containing,…

Sound · Computer Science 2022-07-01 Dejan Markovic , Alexandre Defossez , Alexander Richard

Wavefront sensing is a widely-used non-interferometric, single-shot, and quantitative technique providing the spatial-phase of a beam. The phase is obtained by integrating the measured wavefront gradient. Complex and random wavefields…

Optics · Physics 2021-07-09 Tengfei Wu , Pascal Berto , Marc Guillon

We propose a focal-plane wavefront sensor (FPWFS) based on a short multimode fiber (MMF) capable of operating under moderately broadband illumination. By coupling the aberrated focal-plane field into an MMF of length <1 cm, we preserve…

Instrumentation and Methods for Astrophysics · Physics 2026-03-13 Auxiliadora Padrón-Brito , Natalia Arteaga-Marrero , Ian Cunnyngham , Jeff Kuhn

Spatial aliasing affects spaced microphone arrays, causing directional ambiguity above certain frequencies, degrading spatial and spectral accuracy of beamformers. Given the limitations of conventional signal processing and the scarcity of…

Audio and Speech Processing · Electrical Eng. & Systems 2025-10-21 Mateusz Guzik , Giulio Cengarle , Daniel Arteaga

While adaptive optical systems are able to remove moderate wavefront distortions in scintillated optical beams, phase singularities that appear in strongly scintillated beams can severely degrade the performance of such an adaptive optical…

Optics · Physics 2009-11-13 Mingzhou Chen , Filippus S. Roux , Jan C. Olivier

Continuous wavefront sensing benefits space observatories in on-orbit optical performance maintenance. To measure the phase of a wavefront, phase retrieval is an attractive technique as it uses multiple point spread function (PSF) images…

Instrumentation and Methods for Astrophysics · Physics 2024-09-17 Hyukmo Kang , Kyle Van Gorkom , Meghdoot Biswas , Daewook Kim , Ewan S. Douglas

The problem of identifying regions of spatially interesting, different or adversarial behavior is inherent to many practical applications involving distributed multisensor systems. In this work, we develop a general framework stemming from…

Signal Processing · Electrical Eng. & Systems 2022-06-14 Martin Gölz , Abdelhak M. Zoubir , Visa Koivunen

We address the problem of estimating time and frequency shifts of a known waveform in the presence of multiple measurement vectors (MMVs). This problem naturally arises in radar imaging and wireless communications. Specifically, a signal…

Information Theory · Computer Science 2021-03-01 Maral Safari , Sajad Daei , Farzan Haddadi

An adaptive optics system with a single deformable mirror is being implemented on the THEMIS 90cm solar telescope. This system is designed to operate in the visible and is required to be as robust as possible in order to deliver the best…

Instrumentation and Methods for Astrophysics · Physics 2021-01-11 Michel Tallon , Éric Thiébaut , Maud Langlois , Bernard Gelly , Richard Douet , Clémentine Béchet , Loïc Denis , Gil Moretto

The estimation of atmospheric turbulence parameters is of relevance for: a) site evaluation & characterisation; b) prediction of the point spread function; c) live assessment of error budgets and optimisation of adaptive optics performance;…

Instrumentation and Methods for Astrophysics · Physics 2018-12-19 Paulo P. Andrade , Paulo J. V. Garcia , Carlos M. Correia , Johann Kolb , Maria Inês Carvalho

The quantum wave function of multiple particles provides additional information which is inaccessible to detectors working alone. Here, we introduce the coincidence wavefront sensing (CWS) method to reconstruct the phase of the multiphoton…

Quantum Physics · Physics 2023-05-18 Yi Zheng , Mu Yang , Yu-Wei Liao , Jin-Shi Xu , Chuan-Feng Li , Guang-Can Guo

Currently, many face forgery detection methods aggregate spatial and frequency features to enhance the generalization ability and gain promising performance under the cross-dataset scenario. However, these methods only leverage one level…

Computer Vision and Pattern Recognition · Computer Science 2022-10-11 Jie Liu , Jingjing Wang , Peng Zhang , Chunmao Wang , Di Xie , Shiliang Pu

Spectrum sharing is a new approach to solve the congestion problem in the RF spectrum. A spatial approach for spectrum sharing between a radar and a communication system was proposed, which mitigates the radar interference to communication…

Information Theory · Computer Science 2016-11-17 Awais Khawar , Ahmed Abdelhadi , T. Charles Clancy