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Context. With the arrival of the next generation of ground-based imaging interferometers combining from 4 to possibly 6 telescopes simultaneously, there is also a strong need for a new generation of fringe trackers able to cophase such…

天体物理仪器与方法 · 物理学 2015-05-27 N. Blind , O. Absil , J. -B. Lebouquin , J. -P. Berger , A. Chelli

Counterfactual image generation enables controlled data augmentation, bias mitigation, and disease modeling. However, existing methods guided by external classifiers or regressors are limited to subject-level factors (e.g., age) and fail to…

Digital co-addition of astronomical images is a common technique for increasing signal-to-noise and image depth. A modification of this simple technique has been applied to the detection of minor bodies in the Solar System: first stationary…

地球与行星天体物理 · 物理学 2015-05-18 Alex H. Parker , JJ. Kavelaars

The China Space Station Telescope (CSST) photometric survey aims to perform a high spatial resolution (~0.15'') photometric imaging for the targets that cover a large sky area (~17,500 deg^2) and wide wavelength range (from NUV to NIR). It…

宇宙学与河外天体物理 · 物理学 2022-02-11 Ye Cao , Yan Gong , Zhen-Ya Zheng , Chun Xu

We propose a compact snapshot monocular depth estimation technique that relies on an engineered point spread function (PSF). Traditional approaches used in microscopic super-resolution imaging such as the Double-Helix PSF (DHPSF) are…

图像与视频处理 · 电气工程与系统科学 2022-08-05 Bhargav Ghanekar , Vishwanath Saragadam , Dushyant Mehra , Anna-Karin Gustavsson , Aswin Sankaranarayanan , Ashok Veeraraghavan

Current measurements of the weak lensing signal induced by large scale structure provide useful constraints on a range of cosmological parameters. However, the ultimate succes of this technique depends on the accuracy with which one can…

天体物理学 · 物理学 2009-11-07 Henk Hoekstra

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…

天体物理学 · 物理学 2009-11-13 M. J. Jee , J. P. Blakeslee , M. Sirianni , A. R. Martel , R. L. White , H. C. Ford

Access to knowledge of the point spread function (PSF) of adaptive optics(AO)-assisted observations is still a major limitation when processing AO data. This limitation is particularly important when image analysis requires the use of…

天体物理仪器与方法 · 物理学 2023-05-10 A. Lau , R. JL. Fétick , B. Neichel , O. Beltramo-Martin , T. Fusco

Reaching the high angular resolution and contrast level desired for exoplanetary science requires us to equip large telescopes with extreme adaptive optics (XAO) systems to compensate for the effect of the atmospheric turbulence at a very…

天体物理仪器与方法 · 物理学 2025-11-20 A. Striffling , C. -T. Héritier , R. J. -L Fétick , O. Fauvarque , J. -F Sauvage , A. Carlotti , B. Neichel T. Fusco

Micro-ultrasound (micro-US) is a promising imaging technique for cancer detection and computer-assisted visualization. This study investigates prostate capsule segmentation using deep learning techniques from micro-US images, addressing the…

图像与视频处理 · 电气工程与系统科学 2025-09-22 Kaniz Fatema , Vaibhav Thakur , Emad A. Mohammed

The correction of the influence of phase corrugation in the pupil plane is a fundamental issue in achieving high dynamic range imaging. In this paper, we investigate an instrumental setup which consists in applying interferometric…

天体物理学 · 物理学 2008-11-26 S. Lacour , E. Thiébaut , G. Perrin

Modeling the optical point spread function (PSF) is particularly challenging for adaptive optics (AO)-assisted observations owing to the its complex shape and spatial variations. We aim to (i) exhaustively demonstrate the accuracy of a…

天体物理仪器与方法 · 物理学 2020-11-25 Olivier Beltramo-Martin , Romain Fétick , Benoit Neichel , Thierry Fusco

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…

天体物理仪器与方法 · 物理学 2015-06-18 Benjamin Pope , Nick Cvetojevic , Anthony Cheetham , Frantz Martinache , Barnaby Norris , Peter Tuthill

This paper is the third part of a trilogy dealing with the principles, performance and limitations of what I named "Telescope-Interferometers" (TIs). The basic idea consists in transforming one telescope into a Wavefront Error (WFE) sensing…

光学 · 物理学 2011-05-17 Francois Henault

Galaxy imaging surveys observe a vast number of objects that are affected by the instrument's Point Spread Function (PSF). Weak lensing missions, in particular, aim at measuring the shape of galaxies, and PSF effects represent an important…

天体物理仪器与方法 · 物理学 2021-02-03 T. Liaudat , J. Bonnin , J. -L. Starck , M. A. Schmitz , A. Guinot , M. Kilbinger , S. D. J. Gwyn

The next generation of Extremely Large Telescope (24 to 39m diameter) will suffer from the so-called "pupil fragmentation" problem. Due to their pupil shape complexity (segmentation, large spiders ...), some differential pistons may appear…

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…

计算机视觉与模式识别 · 计算机科学 2017-03-20 F. M. Ngolè Mboula , J. -L. Starck

Laser guide star (LGS) wave-front sensing (LGSWFS) is a key element of tomographic adaptive optics system. However, when considering Extremely Large Telescope (ELT) scales, the LGS spot elongation becomes so large that it challenges the…

Direct imaging of exo-Earths and search for life is one of the most exciting and challenging objectives for future space observatories. Segmented apertures in space will be required to reach the needed large diameters beyond the…

Most adaptive optics (AO) systems using pyramid wavefront sensors (PyWFS) to estimate the phase of the pupil field use mechanical modulation of the beam in order to increase the dynamic range in low-order modes so the PyWFS can usefully…

天体物理仪器与方法 · 物理学 2017-08-31 Richard Frazin