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Related papers: Polarization dOTF: on-sky focal plane wavefront se…

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The recently proposed orthogonal time frequency space (OTFS) modulation multiplexes data symbols in the delay-Doppler (DD) domain. Since the range and velocity, which can be derived from the delay and Doppler shifts, are the parameters of…

Signal Processing · Electrical Eng. & Systems 2023-06-21 Kecheng Zhang , Weijie Yuan , Shuangyang Li , Fan Liu , Feifei Gao , Pingzhi Fan , Yunlong Cai

Real-time seeing estimation at the focus of a telescope is nowadays strongly emphasized as this knowledge virtually drives the dimensioning of adaptive optics systems and instrument operational aspects. In this context we study the interest…

Instrumentation and Methods for Astrophysics · Physics 2015-06-03 P. Martinez , J. Kolb , M. Sarazin , J. Navarrete

A variety of techniques such as light field, structured illumination, and time-of-flight (TOF) are commonly used for depth acquisition in consumer imaging, robotics and many other applications. Unfortunately, each technique suffers from its…

Computer Vision and Pattern Recognition · Computer Science 2015-09-03 Suren Jayasuriya , Adithya Pediredla , Sriram Sivaramakrishnan , Alyosha Molnar , Ashok Veeraraghavan

Wavefront sensing in solar adaptive-optics is currently done with correlating Shack-Hartmann sensors, although the spatial- and temporal-resolutions of the phase measurements are then limited by the extremely fast computing required to…

Instrumentation and Methods for Astrophysics · Physics 2015-05-27 Aglae Kellerer

Digital holography is an interference-based imaging technique capable of recording both the amplitude and phase of an electromagnetic field. It can be obtained at the laser illumination wavelength, but also with second-harmonic generation,…

We investigate methods to calibrate the non-common path aberrations at an adaptive optics system having a wavefront-correcting device working at an extremely high resolution (larger than 150x150). We use focal-plane images collected…

Instrumentation and Methods for Astrophysics · Physics 2015-06-22 Visa Korkiakoski , Christoph U. Keller , Niek Doelman , Matthew Kenworthy , Gilles Otten , Michel Verhaegen

A mathematical relation between elements of one- and multi-dimensional discrete Fourier transforms (DFT) is found. A method of analysing the multi-dimensional data by their single one-dimensional (1-D) DFT is offered. An experiment of…

Numerical Analysis · Mathematics 2025-10-20 Andrew V. Batrac

Newly introduced polarization diversity probing codes are suggested to enhance the sensitivity and bandwidth performance of differential phase-sensitive distributed OTDR systems. This was recently demonstrated by means of short-length…

Signal Processing · Electrical Eng. & Systems 2019-10-23 Christian Dorize , Elie Awwad , Jérémie Renaudier

Context. Solar wavefront sensing has been a challenge for astrophysical instrumentalists, due to the low contrast between the Sun and the sky background compared to night-time observations, which limits the performance of adaptive optics…

In single molecule orientation localization microscopy, valuable information about the orientation and longitudinal position of each molecule is often encoded in the shape of the point spread function (PSF). This shape, though, can be…

Single-shot fluorescence imaging techniques have gained increasing interest in recent years due to their ability to rapidly capture complex biological data without the need for extensive scanning. In this letter, we introduce polarized…

Optics · Physics 2025-01-31 Oumeng Zhang , Changhuei Yang

Time-of-flight (ToF) cameras calculate depth maps by reconstructing phase shifts of amplitude-modulated signals. For broad illumination or transparent objects, reflections from multiple scene points can illuminate a given pixel, giving rise…

Computer Vision and Pattern Recognition · Computer Science 2014-06-20 Ayush Bhandari , Achuta Kadambi , Refael Whyte , Christopher Barsi , Micha Feigin , Adrian Dorrington , Ramesh Raskar

The photoneutron source (PNS, phase 1), an electron linear accelerator (linac)-based pulsed neutron facility that uses the time-of-flight (TOF) technique, was constructed for the acquisition of nuclear data from the thorium molten salt…

The ideal imaging system would efficiently capture information about all fundamental properties light: intensity, direction, wavelength, and polarization. Most common imaging systems only map the spatial degrees of freedom of light onto a…

Optics · Physics 2023-01-26 Conner Ballew , Gregory Roberts , Andrei Faraon

Several types of Wavefront Sensors (WFS) are nowadays available in the field of Adaptive Optics (AO). Generally speaking, their basic principle consists in measuring slopes or curvatures of Wavefront Errors (WFE) transmitted by a telescope,…

Optics · Physics 2011-05-17 Francois Henault

Optical metasurfaces have been recently explored as ultrathin analog image differentiators. By tailoring the momentum transfer function, they can perform efficient Fourier-filtering - and thus potentially any linear mathematical operation -…

Imaging both the polarization and the wavefront of a light beam is a complex task that typically demands several intensity acquisitions. Furthermore, sequential acquisition solutions are incompatible with the monitoring of ultra-fast…

Optics · Physics 2024-07-30 Baptiste Blochet , Grégoire Lelu , Miguel A. Alonso , Marc Guillon

The principal limitation in many areas of astronomy, especially for directly imaging exoplanets, arises from instability in the point spread function (PSF) delivered by the telescope and instrument. To understand the transfer function, it…

Instrumentation and Methods for Astrophysics · Physics 2021-09-01 Alison Wong , Benjamin Pope , Louis Desdoigts , Peter Tuthill , Barnaby Norris , Chris Betters

When inverting solar spectra, image degradation effects that are present in the data are usually approximated or not considered. We develop a data reduction method that takes these issues into account and minimizes the resulting errors. By…

Instrumentation and Methods for Astrophysics · Physics 2015-06-11 M. van Noort

Extraordinary optical transmission and good focusing properties of a two-dimensional scattering structure is presented. The structure is made of Fresnel zone plates periodically arranged along two orthogonal directions. Each plate consists…

Optics · Physics 2013-12-17 A. Roszkiewicz , W. Nasalski
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