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Related papers: Phase Errors in Diffraction-Limited Imaging: Contr…

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Kernel phase interferometry (KPI) is a data processing technique that allows for the detection of asymmetries (such as companions or disks) in high-Strehl images, close to and within the classical diffraction limit. We show that KPI can…

Instrumentation and Methods for Astrophysics · Physics 2023-05-29 Alexander Chaushev , Steph Sallum , Julien Lozi , Frantz Martinache , Jeffrey Chilcote , Tyler Groff , Olivier Guyon , N. Jeremy Kasdin , Barnaby Norris , Andy Skemer

The process of wide-field synthesis imaging is explored, with the aim of understanding the implications of variable, polarised primary beams for forthcoming Epoch of Reionisation experiments. These experiments seek to detect weak signatures…

Instrumentation and Methods for Astrophysics · Physics 2012-06-05 Daniel A. Mitchell , Randall B. Wayth , Gianni Bernardi , Lincoln J. Greenhill , Stephen M. Ord

This paper introduces a novel wavefront sensing approach that relies on the Fourier analysis of a single conventional direct image. In the high Strehl ratio regime, the relation between the phase measured in the Fourier plane and the…

Instrumentation and Methods for Astrophysics · Physics 2015-06-15 Frantz Martinache

The limits for adaptive-optics (AO) imaging at high contrast and high resolution are determined by residual phase errors from non-common-path aberrations not sensed by the wavefront sensor, especially for integral field spectrographs, where…

Instrumentation and Methods for Astrophysics · Physics 2015-06-22 Benjamin Pope , Niranjan Thatte , Rick Burruss , Matthias Tecza , Fraser Clarke , Garret Cotter

We investigate the focal plane wavefront sensing technique, known as Phase Diversity, at the scientific focal plane of a segmented mirror telescope with an adaptive optics (AO) system. We specifically consider an optical system imaging a…

Instrumentation and Methods for Astrophysics · Physics 2021-05-03 Masen Lamb , Carlos Correia , Suresh Sivanandam , Robin Swanson , Polina Zavyalova

Change detection is one of the fundamental applications of synthetic aperture radar (SAR) images. However, speckle noise presented in SAR images has a much negative effect on change detection. In this research, a novel two-phase…

Computer Vision and Pattern Recognition · Computer Science 2020-01-20 Xinzheng Zhang , Guo Liu , Ce Zhang , Peter M Atkinson , Xiaoheng Tan , Xin Jian , Xichuan Zhou , Yongming Li

Laser noise is a decisive limiting factor in high precision spectroscopy of narrow lines using atomic ensembles. In an idealized Doppler and differential light shift free magic wavelength lattice configuration, it remains as one distinct…

Quantum Physics · Physics 2017-03-20 David Plankensteiner , Johannes Schachenmayer , Helmut Ritsch , Claudiu Genes

In astronomy and microscopy, distortions in the wavefront affect the dynamic range of a high contrast imaging system. These aberrations are either imposed by a turbulent medium such as the atmosphere, by static or thermal aberrations in the…

Instrumentation and Methods for Astrophysics · Physics 2015-06-18 Benjamin Pope , Nick Cvetojevic , Anthony Cheetham , Frantz Martinache , Barnaby Norris , Peter Tuthill

The new operational mode of aperture masking interferometry has been added to the CONICA camera which lies downstream of the Adaptive Optics (AO) corrected focus provided by NAOS on the VLT-UT4 telescope. Masking has been shown to deliver…

Instrumentation and Methods for Astrophysics · Physics 2015-05-19 Peter Tuthill , Sylvestre Lacour , Paola Amico , Michael Ireland , Barnaby Norris , Paul Stewart , Tom Evans , Adam Kraus , Chris Lidman , Emanuela Pompei , Nicholas Kornweibel

We study the impact of systematic errors on planned weak lensing surveys and compute the requirements on their contributions so that they are not a dominant source of the cosmological parameter error budget. The generic types of error we…

Astrophysics · Physics 2010-04-06 Dragan Huterer , Masahiro Takada , Gary Bernstein , Bhuvnesh Jain

Quantitative differential phase contrast imaging of materials in atomic-resolution scanning transmission electron microscopy using segmented detectors is limited by various factors, including coherent and incoherent aberrations, detector…

We introduce and experimentally implement Fourier-plane phase synchronization for optical microscopy, and demonstrate its performance with interferometric scattering microscopy. By combining a photothermal phase plate and laser beam…

Phase is a fundamental resource for optical imaging but cannot be directly observed with intensity measurements. The existing methods to quantify a phase distribution rely on complex devices and structures. Here we experimentally…

Optics · Physics 2020-03-25 Tengfeng Zhu , Junyi Huang , Zhichao Ruan

Fringe tracking in interferometers is typically analyzed with the implicit assumption that there is a single phase associated with each telescope in the array. If the telescopes have apertures significantly larger than r0 and only partial…

Astrophysics · Physics 2009-11-13 David F. Buscher , John S. Young , Fabien Baron , Christopher A. Haniff

Being complex-valued and low in signal-to-noise ratios, magnitude-based diffusion MRI is confounded by the noise-floor that falsely elevates signal magnitude and incurs bias to the commonly used diffusion indices, such as fractional…

Computer Vision and Pattern Recognition · Computer Science 2021-06-15 Liu Feihong , Yang Junwei , He Xiaowei , Zhou Luping , Feng Jun , Shen Dinggang

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

Imaging of scenes using light or other wave phenomena is subject to the diffraction limit. The spatial profile of a wave propagating between a scene and the imaging system is distorted by diffraction resulting in a loss of resolution that…

Image and Video Processing · Electrical Eng. & Systems 2020-07-20 Ji Hyun Nam , Andreas Velten

Phase aberrations, despite degrading ultrasound images, also encode valuable information about the spatial distribution of the speed of sound in tissue. In pulse-echo ultrasound, we can quantify them by exploiting speckle correlations.…

Medical Physics · Physics 2025-11-20 Naiara Korta Martiartu , Michael Jaeger

In order to reach the required performance of Stage-III and IV weak lensing surveys, cosmic shear measurements have to rely on external simulations to calibrate residual biases. Over the years, several techniques have been developed to…

Cosmology and Nongalactic Astrophysics · Physics 2025-12-11 G. Congedo , A. N. Taylor

In recent years, computational Time-of-Flight (ToF) imaging has emerged as an exciting and a novel imaging modality that offers new and powerful interpretations of natural scenes, with applications extending to 3D, light-in-flight, and…

Image and Video Processing · Electrical Eng. & Systems 2024-11-05 Ruiming Guo , Ayush Bhandari