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The very large telescope (VLT) interferometer (VLTI) in its current operating state is equipped with high-order adaptive optics (MACAO) working in the visible spectrum. A low-order near-infrared wavefront sensor (IRIS) is available to…

Exoplanet imaging has thus far enabled studies of wide-orbit ($>$10 AU) giant planet ($>$2 Jupiter masses) formation and giant planet atmospheres, with future 30 meter-class Extremely Large Telescopes (ELTs) needed to image and characterize…

Instrumentation and Methods for Astrophysics · Physics 2023-08-14 Benjamin L. Gerard , Daren Dillon , Sylvain Cetre , Rebecca Jensen-Clem

The use of Fourier methods in wave-front reconstruction can significantly reduce the computation time for large telescopes with a high number of degrees of freedom. However, Fourier algorithms for discrete data require a rectangular data…

Instrumentation and Methods for Astrophysics · Physics 2017-06-07 Charlotte Z. Bond , Carlos M. Correia , Jean-François Sauvage , Benoit Neichel , Thierry Fusco

We propose a novel method called SHS-Net for oriented normal estimation of point clouds by learning signed hyper surfaces, which can accurately predict normals with global consistent orientation from various point clouds. Almost all…

Computer Vision and Pattern Recognition · Computer Science 2024-07-31 Qing Li , Huifang Feng , Kanle Shi , Yue Gao , Yi Fang , Yu-Shen Liu , Zhizhong Han

Direct measurement of wave functions has attracted great interests and many different methods have been developed. However, the precision of current techniques is limited by the use of Fourier transform lenses. These measurements require to…

We use spherical cap harmonic (SCH) basis functions to analyse and reconstruct the morphology of scanned genus-0 rough surface patches with open edges. We first develop a novel one-to-one conformal mapping algorithm with minimal area…

Graphics · Computer Science 2024-03-14 Mahmoud Shaqfa , Gary P. T. Choi , Katrin Beyer

We present the first on-sky segmented primary mirror closed-loop piston control using a Zernike wavefront sensor (ZWFS) installed on the Keck II telescope. Segment co-phasing errors are a primary contributor to contrast limits on Keck and…

In share wave elastography (SWE), the aim is to measure the velocity of shear waves, however unwanted compression waves and bulk tissue motion pose challenges in evaluating tissue stiffness. Conventional approaches often struggle to…

Image and Video Processing · Electrical Eng. & Systems 2024-06-19 Hamidreza Asemani , Jannick P. Rolland , Kevin J. Parker

We use wavefront sensing to characterise the image quality of the the High Resolution Telescope (HRT) of the Polarimetric and Helioseismic Imager (SO/PHI) data products during the second remote sensing window of the Solar Orbiter (SO)…

We describe the concept of splitting spatial frequency perturbations into some kind of pupil planes wavefront sensors. Further to the existing approach of dropping higher spatial frequency to suppress aliasing effects (the so-called spatial…

A new inversion method for determining near-surface shear currents from a measured wave spectrum is introduced. The method is straightforward to implement and starts from the existing state-of-the-art technique of assigning effective depths…

Atmospheric and Oceanic Physics · Physics 2020-02-19 Benjamin K. Smeltzer , Eirik Æsøy , Anna Ådnøy , Simen Å. Ellingsen

Wavefront shaping is a technique to study and control light transport inside scattering media. Wavefront shaping is considered to be applicable to any complex material, yet in most previous studies, the only sample geometries that are…

The wavefront measurement of a light beam is a complex task, which often requires a series of spatially resolved intensity measurements. For instance, a detector array may be used to measure the local phase gradient in the transverse plane…

Wavefront shaping systems aim to image deep into scattering tissue by reshaping incoming and outgoing light to correct aberrations caused by tissue inhomogeneity However, the desired modulation depends on the unknown tissue structure and…

Optics · Physics 2026-01-14 Sagi Monin , Marina Alterman , Anat Levin

Optical distortions can significantly deteriorate the measurement accuracy in imaging systems. Such distortions can occur at fluctuating phase boundaries as well as multiple-phase flows and result from the accompanied refractive index…

Applied Physics · Physics 2018-02-21 M. Teich , J. Grottke , H. Radner , L. BÜttner , J. W. Czarske

In this article we show that the vector-Apodizing Phase Plate (vAPP) coronagraph can be designed such that the coronagraphic point spread functions (PSFs) can act as a wavefront sensor to measure and correct the (quasi-)static aberrations,…

Instrumentation and Methods for Astrophysics · Physics 2019-11-27 Steven P. Bos , David S. Doelman , Julien Lozi , Olivier Guyon , Christoph U. Keller , Kelsey L. Miller , Nemanja Jovanovic , Frantz Martinache , Frans Snik

Future large segmented space telescopes and their coronagraphic instruments are expected to provide the resolution and sensitivity to observe Earth-like planets with a 10^10 contrast ratio at less than 100 mas from their host star. Advanced…

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

The Zernike wavefront sensor (ZWFS) is a concept belonging to the wide class Fourier-filtering wavefront sensor (FFWFS). The ZWFS is known for its extremely high sensitivity while having a low dynamic range, which makes it a unique sensor…

Differential wavefront sensing is an essential technique for optimising the performance of many precision interferometric experiments. Perhaps the most extensive application of this is for alignment sensing using radio-frequency beats…

Instrumentation and Detectors · Physics 2021-05-26 Daniel D. Brown , Huy Tuong Cao , Alexei Ciobanu , Peter Veitch , David Ottaway