English
Related papers

Related papers: Reflector Antennas Characterization and Diagnostic…

200 papers

We consider wave propagation problems over 2-dimensional domains with piecewise-linear boundaries, possibly including scatterers. We assume that the wave speed is constant, and that the initial conditions and forcing terms are radially…

Numerical Analysis · Mathematics 2025-03-14 Davide Pradovera , Monica Nonino , Ilaria Perugia

A phase retrieval technique using a spatial light modulator (SLM) and a phase diffuser for a fast reconstruction of smooth wave fronts is demonstrated experimentally. Diffuse illumination of a smooth test object with the aid of a phase…

Optics · Physics 2015-06-11 Mostafa Agour , Percival F. Almoro , Claas Falldorf

The one-dimensional phase retrieval problem consists in the recovery of a complex-valued signal from its Fourier intensity. Due to the well-known ambiguousness of this problem, the determination of the original signal within the extensive…

Numerical Analysis · Mathematics 2021-03-19 Robert Beinert

We present a novel framework to efficiently acquire near-planar anisotropic reflectance in a pixel-independent fashion, using a deep gated mixtureof-experts. While existing work employs a unified network to handle all possible input, our…

Computer Vision and Pattern Recognition · Computer Science 2022-03-30 Xiaohe Ma , Yaxin Yu , Hongzhi Wu , Kun Zhou

In this paper, we propose a new technique for two-dimensional phase unwrapping. The unwrapped phase is found as the solution of an inverse problem that consists in the minimization of an energy functional. The latter includes a weighted…

This paper is concerned with the problem of inverse scattering of time-harmonic acoustic plane waves by a two-layered medium with a locally rough interface in 2D. A direct imaging method is proposed to reconstruct the locally rough…

Numerical Analysis · Mathematics 2023-05-11 Long Li , Jiansheng Yang , Bo Zhang , Haiwen Zhang

A new method recovers phase difference of interfering wavefronts from a pattern of interference fringes, avoiding discontinuity problem. The continuous phase is a solution of the first order differential equation of the interferogram…

Data Analysis, Statistics and Probability · Physics 2024-04-24 V. Berejnov , B. Y. Rubinstein

When performing radio detection of ultra-high energy astroparticles, the planar wavefront model is often used as a first step to evaluate the arrival direction of primary particles. This model estimates the direction by adjusting the…

Instrumentation and Methods for Astrophysics · Physics 2025-03-28 Arsène Ferrière , Simon Prunet , Aurélien Benoit-Lévy , Marion Guelfand , Kumiko Kotera , Matías Tueros

In many signal processing problems arising in practical applications, we wish to reconstruct an unknown signal from its phaseless measurements with respect to a frame. This inverse problem is known as the phase retrieval problem. For each…

Information Theory · Computer Science 2023-07-04 Palina Salanevich

We show that radiation from complex and inherently random but correlated wave sources can be modelled efficiently by using an approach based on the Wigner distribution function. Our method exploits the connection between correlation…

Chaotic Dynamics · Physics 2015-09-30 Gabriele Gradoni , Stephen Creagh , Gregor Tanner , Christopher Smartt , David Thomas

This paper is concerned with the inverse obstacle scattering problem with phaseless far-field data at a fixed frequency. The main difficulty of this problem is the so-called translation invariance property of the modulus of the far-field…

Numerical Analysis · Mathematics 2018-08-29 Bo Zhang , Haiwen Zhang

This paper develops uniqueness theory for 3D phase retrieval with finite, discrete measurement data for strong phase objects and weak phase objects, including: (i) {\em Unique determination of (phase) projections from diffraction patterns}…

Information Theory · Computer Science 2023-12-05 Albert Fannjiang

Electronic wave functions of planar molecules can be reconstructed via inverse Fourier transform of angle-resolved photoelectron spectroscopy (ARPES) data, provided the phase of the electron wave in the detector plane is known. Since the…

Other Condensed Matter · Physics 2016-09-23 Pavel Kliuiev , Tatiana Latychevskaia , Juerg Osterwalder , Matthias Hengsberger , Luca Castiglioni

This study investigates the phase retrieval problem for wide-band signals. We solve the following problem: given f $\in$ L 2 (R) with Fourier transform in L 2 (R, e^{2c|x|} dx), we find all functions g $\in$ L 2 (R) with Fourier transform…

Classical Analysis and ODEs · Mathematics 2020-05-18 Philippe Jaming , Karim Kellay , Rolando Perez

Refractive Index Tomography is the inverse problem of reconstructing the continuously-varying 3D refractive index in a scene using 2D projected image measurements. Although a purely refractive field is not directly visible, it bends light…

Computer Vision and Pattern Recognition · Computer Science 2023-12-06 Brandon Zhao , Aviad Levis , Liam Connor , Pratul P. Srinivasan , Katherine L. Bouman

Fringe projection profilometry (FPP) has become increasingly important in dynamic 3-D shape measurement. In FPP, it is necessary to retrieve the phase of the measured object before shape profiling. However, traditional phase retrieval…

Image and Video Processing · Electrical Eng. & Systems 2020-04-22 Haotian Yu , Xiaoyu Chen , Zhao Zhang , Yi Zhang , Dongliang Zheng , Jing Han

Accurate and fast 3D imaging of specular surfaces still poses major challenges for state-of-the-art optical measurement principles. Frequently used methods, such as phase-measuring deflectometry (PMD) or shape-from-polarization (SfP), rely…

Computer Vision and Pattern Recognition · Computer Science 2024-06-05 Jiazhang Wang , Oliver Cossairt , Florian Willomitzer

Complex field measurements are increasingly becoming the standard for state-of-the-art astronomical instrumentation. Complex field measurements have been used to characterize a suite of ground, airborne, and space-based heterodyne receiver…

Instrumentation and Methods for Astrophysics · Physics 2018-09-25 Kristina K. Davis , Willem Jellema , Stephen J. C. Yates , Christopher E. Groppi , Jochem J. A. Baselmans , Andrey M. Baryshev

We realize mode-multiplexed full-field reconstruction over six spatial and polarization modes after 30-km multimode fiber transmission using intensity-only measurements without any optical carrier or local oscillator at the receiver or…

The coherent radiation emitted by an electron bunch provides a diagnostic signal that can be used to estimate its longitudinal distribution. Commonly only the amplitude of the intensity spectrum can be measured and the associated phase must…

Accelerator Physics · Physics 2015-06-19 Daniele Pelliccia , Tanaji Sen