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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

We report a new coherent imaging technique, termed ptychographic structured modulation (PSM), for quantitative super-resolution microscopy. In this technique, we place a thin diffuser (i.e., a scattering lens) in between the sample and the…

Image and Video Processing · Electrical Eng. & Systems 2019-07-26 Pengming Song , Shaowei Jiang , He Zhang , Zichao Bian , Chengfei Guo , Kazunori Hoshino , Guoan Zheng

Point supervision has become a scalable solution to address dense annotation for infrared small target detection, but its performance is limited by two coupled bottlenecks: unstable pseudo-label evolution in cluttered, low-contrast infrared…

Computer Vision and Pattern Recognition · Computer Science 2026-05-21 Zhu Liu , Yuanhang Yao , Ping Qian , Zihang Chen , Risheng Liu

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

This paper provides a framework for the incorporation of the wavefront sensor measurements in the context of observing modes in which the science camera takes millisecond exposures. In this formulation, the wavefront sensor measurements…

Instrumentation and Methods for Astrophysics · Physics 2015-06-12 Richard A. Frazin

Diffusion models have established new state of the art in a multitude of computer vision tasks, including image restoration. Diffusion-based inverse problem solvers generate reconstructions of exceptional visual quality from heavily…

Image and Video Processing · Electrical Eng. & Systems 2024-08-21 Zalan Fabian , Berk Tinaz , Mahdi Soltanolkotabi

In absence of a lens to form an image, incoherent or partially coherent light scattering off an obstructive or reflective object forms a broad intensity distribution in the far field with only feeble spatial features. We show here that…

This paper describes the wave-front correction and image stabilisation system (CWS) developed for the Sunrise III balloon-borne telescope, and provides information about its performance as measured during the integration into the telescope…

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…

A novel ultra-long distributed vibration sensing (DVS) system using forward transmission and coherent detection is proposed and experimentally demonstrated. In the proposed scheme, a pair of multi-span optical fibers are deployed for…

Signal Processing · Electrical Eng. & Systems 2019-07-19 Yaxi Yan , Changjian Guo , Xiong Wu , Ziqi Lin , Xian Zhou , Faisal Nadeem Khan , Alan Pak Tao Lau , Chao Lu

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

We present an algorithm for coherent diffractive imaging with phaseless measurements. It treats the forward model as a combination of coherent and incoherent waves. The algorithm reconstructs absorption and phase contrast that quantifies…

Computational Physics · Physics 2022-08-25 Miguel Moscoso , Alexei Novikov , George Papanicolaou , Chrysoula Tsogka

A method for producing a laser guide star wavefront sensor for adaptive optics with reduced focal anisoplanatism is presented. A theoretical analysis and numerical simulations have been carried out and the results are presented. The…

Astrophysics · Physics 2009-11-11 T. Butterley , G. D. Love , R. W. Wilson , R. M. Myers , T. J. Morris

Discrete Wavelet Transform (DWT) has been widely explored to enhance the performance of image superresolution (SR). Despite some DWT-based methods improving SR by capturing fine-grained frequency signals, most existing approaches neglect…

Computer Vision and Pattern Recognition · Computer Science 2025-11-05 Peng Du , Hui Li , Han Xu , Paul Barom Jeon , Dongwook Lee , Daehyun Ji , Ran Yang , Feng Zhu

We demonstrate a compact and easy-to-build computational camera for single-shot 3D imaging. Our lensless system consists solely of a diffuser placed in front of a standard image sensor. Every point within the volumetric field-of-view…

Computer Vision and Pattern Recognition · Computer Science 2017-10-06 Nick Antipa , Grace Kuo , Reinhard Heckel , Ben Mildenhall , Emrah Bostan , Ren Ng , Laura Waller

Event cameras or dynamic vision sensors (DVS) record asynchronous response to brightness changes instead of conventional intensity frames, and feature ultra-high sensitivity at low bandwidth. The new mechanism demonstrates great advantages…

Computer Vision and Pattern Recognition · Computer Science 2024-01-09 Bo Zhang , Yuqi Han , Jinli Suo , Qionghai Dai

The wavelength dependence of atmospheric refraction causes elongation of finite-bandwidth images along the elevation vector, which produces spurious signals in weak gravitational lensing shear measurements unless this atmospheric dispersion…

Instrumentation and Methods for Astrophysics · Physics 2015-06-04 Andrés A. Plazas , Gary M. Bernstein

The pyramid wavefront sensor (P-WFS) has replaced the Shack-Hartmann (SH-) WFS as sensor of choice for high performance adaptive optics (AO) systems in astronomy because of its flexibility in pupil sampling, its dynamic range, and its…

Recent ultrasound imaging modalities based on ultrasound computed tomography indicate a huge potential to detect pathologies is tissue due to altered biomechanical properties. Especially the imaging of speed-of-sound (SoS) distribution in…

Medical Physics · Physics 2021-07-05 Richard Rau , Dieter Schweizer , Valery Vishnevskiy , Orcun Goksel

Diffusing wave spectroscopy (DWS) is a group of techniques used to measure the dynamics of a scattering medium in a non-invasive manner. DWS methods rely on detecting the speckle light field from the moving scattering media and measuring…

Image and Video Processing · Electrical Eng. & Systems 2023-07-03 Yu Xi Huang , Simon Mahler , Jerome Mertz , Changhuei Yang