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This paper is concerned with the inverse problem of time-harmonic acoustic scattering by an unbounded, locally rough interface which is assumed to be a local perturbation of a plane. The purpose of this paper is to recover the local…

Analysis of PDEs · Mathematics 2020-08-05 Jianliang Li , Jiaqing Yang , Bo Zhang

In recent years, the mathematical and algorithmic aspects of the phase retrieval problem have received considerable attention. Many papers in this area mention crystallography as a principal application. In crystallography, the signal to be…

Information Theory · Computer Science 2018-06-15 Veit Elser , Ti-Yen Lan , Tamir Bendory

A class of novel STAP algorithms based on sparse recovery technique were presented. Intrinsic sparsity of distribution of clutter and target energy on spatial-frequency plane was exploited from the viewpoint of compressed sensing. The…

Information Theory · Computer Science 2009-04-09 Hao Zhang , Gang Li , Huadong Meng

We propose a scheme for imaging periodic surfaces using a superlens. By employing an inverse scattering model and the transformed field expansion method, we derive an approximate reconstruction formula for the surface profile, assuming…

Numerical Analysis · Mathematics 2024-03-05 Peijun Li , Yuliang Wang

Phase retrieval is a nonlinear inverse problem that arises in a wide range of imaging modalities, from electron microscopy to Fourier ptychography. In particular, the reconstruction is facilitated when the sensing matrix is i.i.d. random,…

In this paper, we present a framework for assessing the effect of non-stationary Gaussian noise and radio frequency interference (RFI) on the signal to noise ratio, the number of false positives detected per true positive and the…

Instrumentation and Methods for Astrophysics · Physics 2017-04-19 E. van Heerden , A. Karastergiou , S. J. Roberts

In pulsar astronomy, detecting effective pulsar signals among numerous pulsar candidates is an important research topic. Starting from space X-ray pulsar signals, the two-dimensional autocorrelation profile map (2D-APM) feature modelling…

Instrumentation and Methods for Astrophysics · Physics 2021-09-08 Longqi Wang , Jing Jin , Lu Liu , Yi Shen

Current pulsar timing array (PTA) analyses do not take full advantage of pulsar distance information, thereby missing out on improved angular resolution and on a potential factor-of-two gain in detection sensitivity for individual…

Instrumentation and Methods for Astrophysics · Physics 2026-05-12 Anna C. Tsai , Dylan L. Jow , Ue-Li Pen

A new method of matrix template matching is presented in the context of pulsar timing analysis. Pulse arrival times are typically measured using only the observed total intensity light curve. The new technique exploits the additional timing…

Astrophysics · Physics 2017-08-02 W. van Straten

This paper is concerned with a nonlinear imaging problem, which aims to reconstruct a locally perturbed, perfectly reflecting, infinite plane from intensity-only (or phaseless) far-field or near-field data. A recursive Newton iteration…

Numerical Analysis · Mathematics 2017-06-06 Bo Zhang , Haiwen Zhang

Compressive Sensing (CS) is a new technique for the efficient acquisition of signals, images, and other data that have a sparse representation in some basis, frame, or dictionary. By sparse we mean that the N-dimensional basis…

Information Theory · Computer Science 2015-05-18 Chinmay Hegde , Richard G. Baraniuk

Hyperparameter tuning of multi-stage pipelines introduces a significant computational burden. Motivated by the observation that work can be reused across pipelines if the intermediate computations are the same, we propose a pipeline-aware…

Machine Learning · Computer Science 2019-03-14 Liam Li , Evan Sparks , Kevin Jamieson , Ameet Talwalkar

Magnetic particle imaging (MPI) data is commonly reconstructed using a system matrix acquired in a time-consuming calibration measurement. The calibration approach has the important advantage over model-based reconstruction that it takes…

Image and Video Processing · Electrical Eng. & Systems 2019-05-09 Ivo Matteo Baltruschat , Patryk Szwargulski , Florian Griese , Mirco Grosser , René Werner , Tobias Knopp

In the phase retrieval problem, an unknown vector is to be recovered given quadratic measurements. This problem has received considerable attention in recent times. In this paper, we present an algorithm to solve a nonconvex formulation of…

Information Theory · Computer Science 2016-06-13 Ritesh Kolte , Ayfer Özgür

Coherent X-ray photons with energies higher than 50 keV offer new possibilities for imaging nanoscale lattice distortions in bulk crystalline materials using Bragg peak phase retrieval methods. However, the compression of reciprocal space…

Signal Processing · Electrical Eng. & Systems 2018-08-14 Siddharth Maddali , Irene Calvo-Almazan , Jonathan Almer , Peter Kenesei , Jun-Sang Park , Ross Harder , Youssef Nashed , Stephan Hruszkewycz

Improving survey specifications are causing an exponential rise in pulsar candidate numbers and data volumes. We study the candidate filters used to mitigate these problems during the past fifty years. We find that some existing methods…

Instrumentation and Methods for Astrophysics · Physics 2016-04-27 R. J. Lyon , B. W. Stappers , S. Cooper , J. M. Brooke , J. D. Knowles

Phase retrieval aims to recover a signal from intensity-only measurements, a fundamental problem in many fields such as imaging, holography, optical computing, crystallography, and microscopy. Although there are several well-known phase…

Image and Video Processing · Electrical Eng. & Systems 2026-01-21 Mehmet Onurcan Kaya , Figen S. Oktem

The problem of estimating the delays and amplitudes of a positive stream of pulses appears in many applications, such as single-molecule microscopy. This paper suggests estimating the delays and amplitudes using a convex program, which is…

Information Theory · Computer Science 2017-01-11 Tamir Bendory

A numerical scheme that uses multi-frequency Newton iterations to reconstruct a rough surface profile between two dielectric media is proposed. At each frequency sample, the scheme employs Newton iterations to solve the nonlinear inverse…

Numerical Analysis · Mathematics 2024-08-29 Ahmet Sefer , Ali Yapar , Hakan Bagci

Atmospheric aerosols have a major influence on the earths climate and public health. Hence, studying their properties and recovering them from light scattering measurements is of great importance. State of the art retrieval methods such as…

Atmospheric and Oceanic Physics · Physics 2021-11-16 Romana Boiger , Rob L. Modini , Alireza Moallemi , David Degen , Martin Gysel-Beer , Andreas Adelmann