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Related papers: Phase Retrieval Problem. Application to VLBI Mappi…

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Our proposed method of random phase-free holography using virtual convergence light can obtain large reconstructed images exceeding the size of the hologram, without the assistance of random phase. The reconstructed images have low-speckle…

This work examines the multi-view compressive phase retrieval problem in a distributed sensor network, where each sensor device, limited by storage and sensing capabilities, can access only intensity measurements from an unknown part of the…

Information Theory · Computer Science 2025-06-02 Ming-Hsun Yang

Recent progress in understanding the physics of magnetic reconnection is conveniently summarized in terms of a phase diagram which organizes the essential dynamics for a wide variety of applications in heliophysics, laboratory and…

Instrumentation and Methods for Astrophysics · Physics 2015-05-30 Hantao Ji , William Daughton

In a variety of fields, in particular those involving imaging and optics, we often measure signals whose phase is missing or has been irremediably distorted. Phase retrieval attempts to recover the phase information of a signal from the…

Information Theory · Computer Science 2019-10-02 Gilles Baechler , Miranda Kreković , Juri Ranieri , Amina Chebira , Yue M. Lu , Martin Vetterli

This paper is concerned with uniqueness, phase retrieval and shape reconstruction methods for inverse elastic scattering problems with phaseless far field data. Systematically, we study two basic models, i.e., inverse scattering of plane…

Analysis of PDEs · Mathematics 2020-01-08 Xia Ji , Xiaodong Liu

In this paper we consider the nonlinear inverse problem of phase retrieval in the context of dynamical sampling. Where phase retrieval deals with the recovery of signals & images from phaseless measurements, dynamical sampling was…

Numerical Analysis · Mathematics 2021-02-02 Robert Beinert , Marzieh Hasannasab

In this document we layout a new method to achieve "bona fide" high precision Very-Long-Baseline-Interferometry (VLBI) astrometric measurements of frequency-dependent positions of celestial sources (even) in the high (mm-wavelength)…

Instrumentation and Methods for Astrophysics · Physics 2009-10-08 Richard Dodson , Maria J. Rioja

Phase retrieval, a nonlinear problem prevalent in imaging applications, has been extensively studied using random models, some of which with i.i.d. sensing matrix components. While these models offer robust reconstruction guarantees, they…

Optics · Physics 2024-09-10 Zhiyuan Hu , Julián Tachella , Michael Unser , Jonathan Dong

Very long baseline interferometry (VLBI) is a radio-astronomical technique in which the correlated signal from various baselines is combined into an image of highest angular resolution. Due to sparsity of the measurements, this imaging…

Instrumentation and Methods for Astrophysics · Physics 2023-03-29 Hendrik Müller , Andrei Lobanov

The ability of a radar to discriminate in both range and Doppler velocity is completely characterized by the ambiguity function (AF) of its transmit waveform. Mathematically, it is obtained by correlating the waveform with its…

Signal Processing · Electrical Eng. & Systems 2024-06-11 Samuel Pinilla , Kumar Vijay Mishra , Brian M. Sadler , Henry Arguello

Phase aberration is one of the primary sources of image quality degradation in ultrasound, which is induced by spatial variations in sound speed across the heterogeneous medium. This effect disrupts transmitted waves and prevents coherent…

Image and Video Processing · Electrical Eng. & Systems 2023-05-18 Mostafa Sharifzadeh , Habib Benali , Hassan Rivaz

High precision astrometric Space Very Long Baseline Interferometry (S-VLBI) at the low end of the conventional frequency range, i.e. 20cm, is a requirement for a number of high priority science goals. These are headlined by obtaining…

Instrumentation and Methods for Astrophysics · Physics 2015-06-15 R. Dodson , M. Rioja , Y. Asaki , H. Imai , X. -Y. Hong , Z. Shen

A unified method for three-dimensional reconstruction of objects from transmission images collected at multiple illumination directions is described. The method may be applicable to experimental conditions relevant to absorption-based,…

Medical Physics · Physics 2022-12-07 Timur E. Gureyev , Hamish G. Brown , Harry M. Quiney , Leslie J. Allen

Interferometry can measure the shape or the material density of a system that could not be measured otherwise by recording the difference between the phase change of a signal and a reference phase. This difference is always between $-\pi$…

Plasma Physics · Physics 2022-10-20 Pierre-Alexandre Gourdain , Aidan Bachmann

The recovery of an unknown signal from its linear measurements is a fundamental problem spanning numerous scientific and engineering disciplines. Commonly, prior knowledge suggests that the underlying signal resides within a known algebraic…

Information Theory · Computer Science 2025-06-27 Zhiqiang Xu

Using very long baseline interferometry (VLBI) observations at (sub)millimeter wavelengths, the Event Horizon Telescope (EHT) currently achieves the finest angular resolution of any astronomical facility, necessary for imaging the…

Instrumentation and Methods for Astrophysics · Physics 2025-10-23 Uri Rolls , Dominic W. Pesce , Paul Tiede , Lindy Blackburn , Iniyan Natarajan , Sheperd S. Doeleman

We study the faint radio population using wide-field very long baseline interferometry (VLBI) observations of 2865 known radio sources in the Cosmic Evolution Survey (COSMOS) field. The main objective of the project was to determine where…

We demonstrate that at 1.4 GHz the combined response of sources detected serendipitously in deep, wide-field VLBI images is sufficient to permit self-calibration techniques to be employed. This technique of "full-beam" VLBI self-calibration…

Astrophysics · Physics 2007-05-23 M. A. Garrett , J. M. Wrobel , R. Morganti

This paper considers the problem of sampling and reconstruction of a continuous-time sparse signal without assuming the knowledge of the sampling instants or the sampling rate. This topic has its roots in the problem of recovering multiple…

Information Theory · Computer Science 2017-01-31 Ayush Bhandari , Aurelien Bourquard , Ramesh Raskar

Phase retrieval (PR) concerns the recovery of complex phases from complex magnitudes. We identify the connection between the difficulty level and the number and variety of symmetries in PR problems. We focus on the most difficult far-field…

Computer Vision and Pattern Recognition · Computer Science 2022-11-03 Zhong Zhuang , David Yang , Felix Hofmann , David Barmherzig , Ju Sun