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The direct detection and imaging of exoplanets requires the use of high-contrast adaptive optics (AO). In these systems quasi-static aberrations need to be highly corrected and calibrated. In order to achieve this, the pupil-modulated…

Instrumentation and Methods for Astrophysics · Physics 2022-05-25 Nicolas Dubost , Nazim Ali Bharmal , Marc Dubbeldam , Richard M. Myers

Intelligent reflecting surface (IRS) that enables the control of the wireless propagation environment has been looked upon as a promising technology for boosting the spectrum and energy efficiency in future wireless communication systems.…

Signal Processing · Electrical Eng. & Systems 2020-02-26 Samith Abeywickrama , Rui Zhang , Chau Yuen

Wavefront shaping is a technique for directing light through turbid media. The theoretical aspects of wavefront shaping are well understood, and under near-ideal experimental conditions, accurate predictions for the expected signal…

Optics · Physics 2024-07-01 Bahareh Mastiani , Daniël W. S. Cox , Ivo M. Vellekoop

Four-wave mixing (FWM) is an important nonlinear optical phenomenon that underlines many of the discoveries and device applications since the laser was invented. Examples include parametric amplification, mode-locked pulses and frequency…

Many problems on signal processing reduce to nonparametric function estimation. We propose a new methodology, piecewise convex fitting (PCF), and give a two-stage adaptive estimate. In the first stage, the number and location of the change…

Methodology · Statistics 2020-02-18 Kurt Riedel

The concept of Wavelength Frame Multiplication (WFM) was developed to extend the usable wavelength range on long pulse neutron sources for instruments using pulse shaping choppers. For some instruments, it is combined with a pulse shaping…

Instrumentation and Detectors · Physics 2013-07-18 D. Nekrassov , C. Zendler , K. Lieutenant

State estimation for nonlinear dynamical systems is a critical challenge in control and engineering applications, particularly when only partial and noisy measurements are available. This paper introduces a novel Adaptive Physics-Informed…

Machine Learning · Computer Science 2025-10-31 Ayoub Farkane , Mohamed Boutayeb , Mustapha Oudani , Mounir Ghogho

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 identification of dynamical systems, the prediction error method using a quadratic cost function provides asymptotically efficient estimates under Gaussian noise and additional mild assumptions, but in general it requires solving a…

Systems and Control · Computer Science 2018-03-28 Miguel Galrinho , Cristian R. Rojas , Hakan Hjalmarsson

An important factor which affects performance of solar adaptive optics (AO) systems is the accuracy of tracking an extended object in the wavefront sensor. The accuracy of a centre-ofmass approach to image shift measurement depends on the…

Instrumentation and Methods for Astrophysics · Physics 2015-08-21 M. J. Townson , A. Kellerer , C. D. Saunter

Wavefront estimation using in-focus image data is critical to many applications. This data is invariant to a sign flip with complex conjugation of the complex amplitude in the pupil, making for a non-unique solution. Information from an…

Instrumentation and Methods for Astrophysics · Physics 2016-07-08 Alexandra Greenbaum , Anand Sivaramakrishnan

PieceWise Affine (PWA) approximations for nonlinear functions have been extensively used for tractable, computationally efficient control of nonlinear systems. However, reaching a desired approximation accuracy without prior information…

Systems and Control · Electrical Eng. & Systems 2025-11-04 Leila Gharavi , Bart De Schutter , Simone Baldi

Sub-pixel matching of multimodal optical images is a critical step in combined application of multiple sensors. However structural noise and inconsistencies arising from variations in multimodal image responses usually limit the accuracy of…

Computer Vision and Pattern Recognition · Computer Science 2026-01-06 Tao Huang , Hongbo Pan , Nanxi Zhou , Siyuan Zou , Shun Zhou

Seismic full waveform inversion (FWI) is a powerful technique to generate high resolution images of the Earth's interior. However, significant uncertainty exists in all FWI solutions due to imperfect acquisition geometries, inherent noise…

Geophysics · Physics 2026-03-13 Xuebin Zhao , Andrew Curtis

We present a high-precision temporal-spatial phase-demodulation algorithm for phase-shifting interferometry (PSI) affected by random/systematic phase-stepping errors. Laser interferometers in standard optical-shops suffer from several error…

Signal Processing · Electrical Eng. & Systems 2019-12-11 Manuel Servin , Moises Padilla , Guillermo Garnica , Gonzalo Paez

The family of multi-plane phase retrieval sensors, such as the curvature and nonlinear curvature wavefront sensors (WFS), contain tip/tilt information embedded in their signals. We have built a nonlinear curvature WFS to study different…

Instrumentation and Methods for Astrophysics · Physics 2026-03-12 Caleb G. Abbott , Justin R. Crepp , Brian Sands

Atmospheric turbulence degrades the quality of astronomical observations in ground-based telescopes, leading to distorted and blurry images. Adaptive Optics (AO) systems are designed to counteract these effects, using atmospheric…

Instrumentation and Methods for Astrophysics · Physics 2025-04-27 Jeffrey Smith , Taisei Fujii , Jesse Cranney , Charles Gretton

Future large space telescopes will be equipped with adaptive optics (AO) to overcome wavefront aberrations and achieve high contrast for imaging faint astronomical objects, such as earth-like exoplanets and debris disks. In contrast to AO…

Instrumentation and Methods for Astrophysics · Physics 2020-01-07 He Sun , N. Jeremy Kasdin , Robert Vanderbei

A near-field sensing (NISE) enabled predictive beamforming framework is proposed to facilitate wireless communications with high-mobility channels. Unlike conventional far-field sensing, which only captures the angle and the radial velocity…

Signal Processing · Electrical Eng. & Systems 2024-10-23 Hao Jiang , Zhaolin Wang , Yuanwei Liu

The measurement of spin-precession and orbital eccentricity in gravitational-wave (GW) signals is a key priority in GW astronomy, as these effects not only provide insights into the astrophysical formation and evolution of compact binaries…

General Relativity and Quantum Cosmology · Physics 2025-04-22 Gonzalo Morras , Geraint Pratten , Patricia Schmidt