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Related papers: Fourier phase analysis in radio-interferometry

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Efficient estimators of Fourier-space statistics for large number of objects rely on Fast Fourier Transforms (FFTs), which are affected by aliasing from unresolved small scale modes due to the finite FFT grid. Aliasing takes the form of a…

Cosmology and Nongalactic Astrophysics · Physics 2017-10-09 Emiliano Sefusatti , Martin Crocce , Roman Scoccimarro , Hugh Couchman

Phase retrieval, i.e., the problem of recovering a function from the squared magnitude of its Fourier transform, arises in many applications such as X-ray crystallography, diffraction imaging, optics, quantum mechanics, and astronomy. This…

Image and Video Processing · Electrical Eng. & Systems 2020-12-02 Albert Fannjiang , Thomas Strohmer

The spatio-temporal dynamics of the deformation of a vibrated plate is measured by a high speed Fourier transform profilometry technique. The space-time Fourier spectrum is analyzed. It displays a behavior consistent with the premises of…

Chaotic Dynamics · Physics 2011-07-13 Nicolas Mordant

Fourier phase retrieval is a classical problem that deals with the recovery of an image from the amplitude measurements of its Fourier coefficients. Conventional methods solve this problem via iterative (alternating) minimization by…

Image and Video Processing · Electrical Eng. & Systems 2020-07-30 Rakib Hyder , Zikui Cai , M. Salman Asif

Spatial, amplitude and phase variations in spatial functional data are confounded. Conclusions from the popular functional trace variogram, which quantifies spatial variation, can be misleading when analysing misaligned functional data with…

Methodology · Statistics 2020-10-20 Xiaohan Guo , Sebastian Kurtek , Karthik Bharath

The present constraints on fundamental constant variation (\alpha and \mu) obtained in the radio range are reviewed, coming essentially from absorption lines in front of quasars of intermediate to high-z galaxies, through CO, HI, OH, HCO+,…

Cosmology and Nongalactic Astrophysics · Physics 2009-10-06 F. Combes

Radio frequency interference (RFI) is a significant challenge faced by today's radio astronomers. While most past efforts were devoted to cleaning the RFI from the data, we develop a novel method for categorizing and cataloguing RFI for…

Instrumentation and Methods for Astrophysics · Physics 2023-06-07 Mao Yuan , Weiwei Zhu , Haiyan Zhang , Shijie Huang , Mengyao Xue , Di Li , Youling Yue , Pei Wang , 1 Jiarui Niu , Yuxuan Hu , Chunjiang Li , Chenchen Miao , Yu Wang , Lingqi Meng , Bo Peng

Quantum correlation, such as entanglement and squeezing have shown to improve phase estimation in interferometric setups on one side, and non-interferometric imaging scheme of amplitude object on the other. In the last case, quantum…

We present the results of the \textit{Fermi}-LAT 10-years-long light curves (LCs) modeling of selected blazars: six flat spectrum radio quasars (FSRQs) and five BL Lacertae (BL Lacs), examined in 7-, 10-, and 14-day binning. The LCs and…

High Energy Astrophysical Phenomena · Physics 2021-09-24 Mariusz Tarnopolski , Natalia Żywucka , Volodymyr Marchenko , Javier Pascual-Granado

Quantitative helio- and asteroseismology require very precise measurements of the frequencies, amplitudes, and lifetimes of the global modes of stellar oscillation. It is common knowledge that the precision of these measurements depends on…

Astrophysics · Physics 2009-11-13 Thorsten Stahn , Laurent Gizon

In portable, 3-D, or ultra-fast ultrasound (US) imaging systems, there is an increasing demand to reconstruct high quality images from limited number of data. However, the existing solutions require either hardware changes or…

Computer Vision and Pattern Recognition · Computer Science 2017-10-31 Yeo Hun Yoon , Jong Chul Ye

The problem of recovering a signal from its phaseless Fourier transform measurements, called Fourier phase retrieval, arises in many applications in engineering and science. Fourier phase retrieval poses fundamental theoretical and…

Information Theory · Computer Science 2017-11-08 Tamir Bendory , Robert Beinert , Yonina C. Eldar

The phase retrieval from multi-frequency intensity (power) observations is considered. The object to be reconstructed is complex-valued. A novel algorithm is presented that accomplishes both the object phase (absolute phase) retrieval and…

Signal Processing · Electrical Eng. & Systems 2018-02-07 Vladimir Katkovnik , Karen Egiazarian

One of the most powerful approaches to imaging at the nanometer or subnanometer length scale is coherent diffraction imaging using X-ray sources. For amorphous (non-crystalline) samples, the raw data can be interpreted as the modulus of the…

Numerical Analysis · Mathematics 2020-04-02 Alexander Barnett , Charles L. Epstein , Leslie Greengard , Jeremy Magland

In this paper, we introduce two symmetric directed graphs depending on supports of signals and windows, and we show that the connectivity of those graphs provides either necessary and sufficient conditions to phase retrieval of a signal…

Information Theory · Computer Science 2017-02-22 Lan Li , Cheng Cheng , Deguang Han , Qiyu Sun , Guangming Shi

This work studies phase retrieval for wave fields, aiming to recover the phase of an incoming wave from multi-plane intensity measurements behind different types of linear and nonlinear media. We show that unique phase retrieval can be…

Optics · Physics 2025-05-22 Yan Cheng , Kui Ren , Nathan Soedjak

A method based on the Fast Fourier Transform is proposed to obtain the dispersion relation of acoustic waves in heterogeneous periodic media with arbitrary microstructures. The microstructure is explicitly considered using a voxelized…

Materials Science · Physics 2021-06-24 J. Segurado , R. A. Lebensohn

Spatial interferometry, based on the measurement of total absorbed power, can be used to determine the state of coherence of the electromagnetic field to which any energy-absorbing structure is sensitive. The measured coherence tensor can…

Quantum Physics · Physics 2015-06-11 Stafford Withington , Christopher N. Thomas

Intrinsic spectrum that results from the coupling of spontaneous emission in a laser cavity, can determine the energy concentration and coherence of lasers, which is crucial for the optical high-precision measurement. Up to now, it is hard…

A function has been proposed to evaluate the electron density model constructed by inverse Fourier transform using the observed structure amplitudes and trial phase set. The strategy of this function is applying an imaginary electron…

Materials Science · Physics 2018-03-28 Hui Li , Meng He , Ze Zhang