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Wavefront sensing is a widely-used non-interferometric, single-shot, and quantitative technique providing the spatial-phase of a beam. The phase is obtained by integrating the measured wavefront gradient. Complex and random wavefields…

Optics · Physics 2021-07-09 Tengfei Wu , Pascal Berto , Marc Guillon

A wavelet-based changepoint method is proposed that determines when the variability of the noise in a sequence of functional profiles goes out-of-control from a known, fixed value. The functional portion of the profiles are allowed to come…

Methodology · Statistics 2015-08-20 Vladimir J. Geneus , Eric Chicken , Jordan Cuevas , Joseph J. Pignatiello

We consider sequential and parallel decomposition methods for a dual problem of a general total variation minimization problem with applications in several image processing tasks, like image inpainting, estimation of optical flow and…

Numerical Analysis · Mathematics 2022-11-02 Stephan Hilb , Andreas Langer

The recently developed globally convergent numerical method for an inverse medium problem for the Helmholtz equation is tested on experimental data. The data were originally collected in the time domain, whereas the method works in the…

Numerical Analysis · Mathematics 2016-10-26 Aleksandr E. Kolesov , Michael V. Klibanov , Loc H. Nguyen , Dinh-Liem Nguyen , Nguyen T. Thanh

Decomposing oceanic and atmospheric flow fields into their slowly evolving balanced components and fast evolving wave components is essential for understanding processes like spontaneous wave emission. To study these processes, the…

Atmospheric and Oceanic Physics · Physics 2025-01-22 Silvano Gordian Rosenau , Manita Chouksey , Carsten Eden

Single-wavelength interferometry achieves high resolution for smooth surfaces but struggles with rough, industrially relevant ones due to limited unambiguous measuring range and speckle effects. Multi-wavelength interferometry addresses…

A method is described for predicting statistical properties of turbulence. Collections of Fourier amplitudes are represented by nonuniformly spaced modes with enhanced coupling coefficients. The statistics of the full dynamics can be…

chao-dyn · Physics 2009-10-31 John C. Bowman , B. A. Shadwick , P. J. Morrison

In many signal processing applications, one wishes to acquire images that are sparse in transform domains such as spatial finite differences or wavelets using frequency domain samples. For such applications, overwhelming empirical evidence…

Computer Vision and Pattern Recognition · Computer Science 2013-10-22 Felix Krahmer , Rachel Ward

In this paper we study the problem of computing wavelet coefficients of compactly supported functions from their Fourier samples. For this, we use the recently introduced framework of generalized sampling. Our first result demonstrates that…

Numerical Analysis · Mathematics 2013-05-14 Ben Adcock , Anders C. Hansen , Clarice Poon

Wavelet analysis is proposed as a new tool for studying the large-scale structure formation of the universe. To reveal its usefulness, the wavelet decomposition of one-dimensional cosmological density fluctuations is performed. In contrast…

Astrophysics · Physics 2009-10-28 Yoshi Fujiwara , Jiro Soda

We develop an iterative, adaptive frequency sensing protocol based on Ramsey interferometry of a two-level system. Our scheme allows one to estimate unknown frequencies with a high precision from short, finite signals. It avoids several…

Applied Physics · Physics 2023-08-16 Avishek Chowdhury , Anh Tuan Le , Eva M. Weig , Hugo Ribeiro

This paper introduces a new pseudodifferential preconditioner for the Helmholtz equation in variable media with absorption. The pseudodifferential operator is associated with the multiplicative inverse to the symbol of the Helmholtz…

Numerical Analysis · Mathematics 2024-12-12 Sebastian Acosta , Tahsin Khajah , Benjamin Palacios

We address the problem of estimating time and frequency shifts of a known waveform in the presence of multiple measurement vectors (MMVs). This problem naturally arises in radar imaging and wireless communications. Specifically, a signal…

Information Theory · Computer Science 2021-03-01 Maral Safari , Sajad Daei , Farzan Haddadi

The objective of the present paper is to introduce the concept of a spatially inhomogeneous linear inverse problem where the degree of ill-posedness of operator $Q$ depends not only on the scale but also on location. In this case, the rates…

Statistics Theory · Mathematics 2013-12-05 Marianna Pensky

The 21 cm radiation of neutral hydrogen provides crucial information for studying the early universe and its evolution. To advance this research, countries have made significant investments in constructing large low-frequency radio…

Instrumentation and Methods for Astrophysics · Physics 2025-08-04 Ming-wei Qin , Rui Tang , Ying-hui Zhou , Chang-jun Lan , Wen-hao Fu , Huan Wang , Bao-lin Hou , Zamri , Jin-song Ping , Wen-jun Yang , Liang Dong

Here we present a method of constructing steerable wavelet frames in $L_2(\mathbb{R}^d)$ that generalizes and unifies previous approaches, including Simoncelli's pyramid and Riesz wavelets. The motivation for steerable wavelets is the need…

Classical Analysis and ODEs · Mathematics 2014-02-20 John Paul Ward , Michael Unser

For the multi-resolution of wavelet transform, it used to filter the complex gamma Spectrum, the fluctuation is filtered, while the detector resolution is still kept well, which has been demonstrated as a new, promising technique for gamma…

Data Analysis, Statistics and Probability · Physics 2013-09-16 Zhang Jinzhao , Tuo Xianguo

In this paper we study the problem of density deconvolution under general assumptions on the measurement error distribution. Typically deconvolution estimators are constructed using Fourier transform techniques, and it is assumed that the…

Statistics Theory · Mathematics 2020-02-04 Denis Belomestny , Alexander Goldenshluger

This article combines wavelet analysis techniques with machine learning methods for univariate time series forecasting, focusing on three main contributions. Firstly, we consider the use of Daubechies wavelets with different numbers of…

Methodology · Statistics 2024-03-14 Guy P Nason , James L. Wei