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Atmospheric optical turbulence (OT) monitoring is crucial for site characterisation at astronomical observatories and optical communications ground stations. The Shack-Hartmann Image Motion Monitor (SHIMM) instrument implements a fast,…

Instrumentation and Methods for Astrophysics · Physics 2026-04-29 Ryan Griffiths , Timothy Butterley , Richard Wilson , James Osborn

Measurements of the optical turbulence profile above Siding Spring Observatory were conducted during 2005 and 2006. This effort was largely motivated by the need to predict the statistical performance of adaptive optics at Siding Spring.…

Instrumentation and Methods for Astrophysics · Physics 2015-06-11 Michael Goodwin , Charles Jenkins , Andrew Lambert

A novel approach is presented to recover an image degraded by atmospheric turbulence. Given a sequence of frames affected by turbulence, we construct a variational model to characterize the static image. The optimization problem is solved…

Computer Vision and Pattern Recognition · Computer Science 2024-11-05 Yu Mao , Jerome Gilles

We present a concept of a millimeter wavefront sensor that allows real-time sensing of the surface of a ground-based millimeter/submillimeter telescope. It is becoming important for ground-based millimeter/submillimeter astronomy to make…

One of the greatest challenges in utilizing multimode optical fibers is mode-mixing and inter-modal interference, which scramble the information delivered by the fiber. A common approach for canceling these effects is to tailor the optical…

The term wavefront sensor refers to the entire class of devices capable of measuring the optical wavefront of the incoming beam. Although numerous solutions have been proposed so far, recent advances in structured light have opened new…

Silicon photonic wavefront phase-tilt sensors for wavefront monitoring using surface coupling grating arrays are demonstrated. The first design employs the intrinsic angle dependence of the grating coupling efficiency to determine local…

In this paper, we derive a new class of methods for the classic 2D phase unwrapping problem of recovering a phase function from its wrapped form. For this, we consider the wrapped phase as a wavefront aberration in an optical system, and…

Numerical Analysis · Mathematics 2025-03-14 Simon Hubmer , Victoria Laidlaw , Ronny Ramlau , Ekaterina Sherina , Bernadett Stadler

First multi-conjugate adaptive-optical (MCAO) systems are currently being installed on solar telescopes. The aim of these systems is to increase the corrected field-of-view with respect to conventional adaptive optics. However, this first…

Instrumentation and Methods for Astrophysics · Physics 2015-06-05 Aglae Kellerer

It has been demonstrated that dynamic refractive index modulation, which breaks time-reversal symmetry, can be used to create on-chip non-reciprocal photonic devices. In order to achieve amplitude non-reciprocity, all such devices moreover…

Adaptive optics (AO) is a technology in modern ground-based optical telescopes to compensate the wavefront distortions caused by atmospheric turbulence. One method that allows to retrieve information about the atmosphere from telescope data…

Instrumentation and Methods for Astrophysics · Physics 2018-04-04 Tapio Helin , Stefan Kindermann , Jonatan Lehtonen , Ronny Ramlau

Context. The new giant segmented mirror telescopes will use laser guide stars (LGS) for their adaptive optics (AO) systems. Two options to use as wavefront sensors (WFS) are the Shack-Hartmann wavefront sensor (SHWFS) and the pyramid…

Instrumentation and Methods for Astrophysics · Physics 2024-10-08 Francisco Oyarzun , Cedric-Taissir Heritier , Vincent Chambouleyron , Thierry Fusco , Paul Rouquette , Benoit Neichel

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

A scheme is proposed to achieve substantial controllable phase modulation for a probe field propagating through a thermal atomic vapor in double-$\Lambda$ configuration. The phase modulation is based on the linear susceptibility of the…

Quantum Physics · Physics 2015-06-19 Lida Zhang , Jörg Evers

While Fourier ptychography (FP) offers super-resolution for macroscopic imaging, its real-world application is severely hampered by atmospheric turbulence, a challenge largely unaddressed in existing macroscopic FP research operating under…

The success of ground-based instruments for high contrast exoplanet imaging depends on the degree to which adaptive optics (AO) systems can mitigate atmospheric turbulence. While modern AO systems typically suffer from millisecond time lags…

Instrumentation and Methods for Astrophysics · Physics 2019-09-13 Rebecca Jensen-Clem , Charlotte Z. Bond , Sylvain Cetre , Eden McEwen , Peter Wizinowich , Sam Ragland , Dimitri Mawet , James Graham

Ptychography has become prominent at synchrotron facilities worldwide for characterizing biological and material specimens' topological structures and properties at the nanometer or atomic scale, due to its lens - less, highly quantitative…

Image and Video Processing · Electrical Eng. & Systems 2025-01-28 Tao Liu , Bingyang Wang , JiangTao Zhao , Maik Kahnt , Fucai Zhang

Doppler radars are routinely used for the remote sensing of oceanic surface currents and atmospheric wind profiles. Even though they operate at different frequencies and address different media, they follow very similar processing for the…

Atmospheric and Oceanic Physics · Physics 2021-02-02 Baptiste Domps , Julien Marmain , Charles-Antoine Guérin

Atmospheric Turbulence (AT) correction is a challenging restoration task as it consists of two distortions: geometric distortion and spatially variant blur. Diffusion models have shown impressive accomplishments in photo-realistic image…

Computer Vision and Pattern Recognition · Computer Science 2023-07-28 Xijun Wang , Santiago López-Tapia , Aggelos K. Katsaggelos

As we look to the next generation of adaptive optics systems, now is the time to develop and explore the technologies that will allow us to image rocky Earth-like planets; wavefront control algorithms are not only a crucial component of…

Earth and Planetary Astrophysics · Physics 2023-09-06 J. Fowler , Rico Landman
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