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In ground-based astronomy, Adaptive Optics (AO) is a pivotal technique, engineered to correct wavefront phase distortions and thereby enhance the quality of the observed images. Integral to an AO system is the wavefront sensor (WFS), which…

Instrumentation and Methods for Astrophysics · Physics 2026-05-07 Yutong Wu , Roland Wagner , Ronny Ramlau , Raymond H. Chan

Large ground-based telescopes equipped with adaptive optics (AO) systems have ushered in a new era of high-resolution infrared photometry and astrometry. Relative astrometric accuracies of <0.2 mas have already been demonstrated from…

Instrumentation and Methods for Astrophysics · Physics 2015-05-19 Jessica R. Lu , Andrea M. Ghez , Sylvana Yelda , Tuan Do , Will Clarkson , Nate McCrady , Mark R. Morris

The Global-Multi Conjugated Adaptive Optics (GMCAO) approach offers an alternative way to correct an adequate scientific Field of View (FoV) using only natural guide stars (NGSs) to extremely large ground-based telescopes. Thus, even in the…

Instrumentation and Methods for Astrophysics · Physics 2020-07-01 Elisa Portaluri , Valentina Viotto , Roberto Ragazzoni , Carmelo Arcidiacono , Maria Bergomi , Marco Dima , Davide Greggio , Jacopo Farinato , Demetrio Magrin

We present significantly improved proper motion measurements of the Milky Way's central stellar cluster. These improvements are made possible by refining our astrometric reference frame with a new geometric optical distortion model for the…

Astrophysics of Galaxies · Physics 2015-05-20 Sylvana Yelda , Jessica R. Lu , Andrea M. Ghez , Will Clarkson , Jay Anderson , Tuan Do , Keith Matthews

Future large space telescopes will be equipped with adaptive optics (AO) to overcome wavefront aberrations and achieve high contrast for imaging faint astronomical objects, such as earth-like exoplanets and debris disks. In contrast to AO…

Instrumentation and Methods for Astrophysics · Physics 2020-01-07 He Sun , N. Jeremy Kasdin , Robert Vanderbei

The future large adaptive telescopes will trigger new constraints for the calibration of Adaptive Optics (AO) systems equipped with pre-focal Deformable Mirrors (DM). The image of the DM actuators grid as seen by the Wave-Front Sensor (WFS)…

Instrumentation and Methods for Astrophysics · Physics 2021-05-26 C. T. Heritier , T. Fusco , S. Oberti , B. Neichel , S. Esposito , P. -Y. Madec

As an efficient image contrast enhancement (CE) tool, adaptive gamma correction (AGC) was previously proposed by relating gamma parameter with cumulative distribution function (CDF) of the pixel gray levels within an image. ACG deals well…

Multimedia · Computer Science 2022-08-31 Gang Cao , Lihui Huang , Huawei Tian , Xianglin Huang , Yongbin Wang , Ruicong Zhi

State-of-the-art object pose estimation methods are prone to generating geometrically infeasible pose hypotheses. This problem is prevalent in dexterous manipulation, where estimated poses often intersect with the robotic hand or are not…

Robotics · Computer Science 2026-03-24 Anil Zeybek , Rhys Newbury , Snehal Dikhale , Nawid Jamali , Soshi Iba , Akansel Cosgun

Many studies have been conducted so far on image restoration, the problem of restoring a clean image from its distorted version. There are many different types of distortion which affect image quality. Previous studies have focused on…

Computer Vision and Pattern Recognition · Computer Science 2019-04-09 Masanori Suganuma , Xing Liu , Takayuki Okatani

Many adaptive optics systems operate by measuring the distortion of the wavefront in one wavelength range and performing the scientific observations in a second, different wavelength range. One common technique is to measure wavefront…

Astrophysics · Physics 2009-11-07 Henry G. Roe

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

Over the last two decades the Andromeda Galaxy (M31) has been something of a test-bed for methods aimed at obtaining accurate time-domain relative photometry within highly crowded fields. Difference imaging methods, originally pioneered…

Astrophysics of Galaxies · Physics 2015-05-18 E. Kerins , M. J. Darnley , J. P. Duke , A. Gould , C. Han , A. Newsam , B. -G. Park , R. Street

Background The accuracy of photomechanics measurements critically relies on image quality,particularly under extreme illumination conditions such as welding arc monitoring and polished metallic surface analysis. High dynamic range (HDR)…

Computer Vision and Pattern Recognition · Computer Science 2026-02-16 Banglei Guan , Jing Tao , Liang Xu , Dongcai Tan , Pengju Sun , Jianbing Liu , Yang Shang , Qifeng Yu

Astronomical imaging using aperture synthesis telescopes requires deconvolution of the point spread function as well as calibration of instrumental and atmospheric effects. In general, such effects are time-variable and vary across the…

Astrophysics · Physics 2009-11-13 S. Bhatnagar , T. J. Cornwell , K. Golap , Juan M. Uson

Reconstruction of geometric structures from images using supervised learning suffers from limited available amount of accurate data. One type of such data is accurate real-world RGB-D images. A major challenge in acquiring such ground truth…

Computer Vision and Pattern Recognition · Computer Science 2022-04-13 Noam Rotstein , Amit Bracha , Ron Kimmel

Optical aberrations of optical systems cause significant degradation of imaging quality. Aberration correction by sophisticated lens designs and special glass materials generally incurs high cost of manufacturing and the increase in the…

Computer Vision and Pattern Recognition · Computer Science 2023-04-13 Shuang Cui , Bingnan Wang , Quan Zheng

Microscope objectives achieve near diffraction-limited performance only when used under the conditions they are designed for. In non-standard geometries, such as thick cover slips or curved surfaces, severe aberrations arise, inevitably…

Optics · Physics 2025-03-24 D. W. S. Cox , T. Knop , I. M. Vellekoop

Context. For accurately measuring intensities and determining magnetic field strengths of small-scale solar (magnetic) structure, knowledge of and compensation for the point spread function is crucial. For images recorded with the Swedish…

Instrumentation and Methods for Astrophysics · Physics 2015-05-19 G. B. Scharmer , M. G. Löfdahl , T. I. M. van Werkhoven , J. de la Cruz Rodriguez

In this paper, we address the inverse problem of fast, stable, and high-quality wavefront reconstruction from pyramid wavefront sensor data for Adaptive Optics systems on Extremely Large Telescopes. For solving the indicated problem we…

Instrumentation and Methods for Astrophysics · Physics 2019-05-01 Victoria Hutterer , Ronny Ramlau , Iuliia Shatokhina

High-throughput 2D and 3D scanning electron microscopy, which relies on automation and dependable control algorithms, requires high image quality with minimal human intervention. Classical focus and astigmatism correction algorithms attempt…

Instrumentation and Detectors · Physics 2023-05-10 Philipp Johannes Schubert , Rangoli Saxena , Joergen Kornfeld