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Related papers: Fast Holographic Deconvolution: a new technique fo…

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High angular resolution diffusion imaging (HARDI) demands a lager amount of data measurements compared to diffusion tensor imaging, restricting its use in practice. In this work, we explore a learning-based approach to reconstruct HARDI…

Computer Vision and Pattern Recognition · Computer Science 2019-03-25 Shi Yin , Zhengqiang Zhang , Qinmu Peng , Xinge You

Interferometric arrays seeking to measure the 21 cm signal from the Epoch of Reionization must contend with overwhelmingly bright emission from foreground sources. Accurate recovery of the 21 cm signal will require precise calibration of…

The non transparency and severe propagation effects of the terrestrial ionosphere make it impossible for Earth based instruments to study the universe at low radio frequencies. An exploration of the low frequency radio window with the…

Astrophysics · Physics 2007-05-23 Divya Oberoi , Jean-Louis Pinçon

Large-scale antenna (LSA) has gained a lot of attention recently since it can significantly improve the performance of wireless systems. Similar to multiple-input multiple-output (MIMO) orthogonal frequency division multiplexing (OFDM) or…

Information Theory · Computer Science 2016-07-20 Yinsheng Liu , Geoffrey Ye Li , Wei Han , Zhangdui Zhong

Low frequency imaging radio arrays such as MWA, LWA and LOFAR have been recently commissioned, and significantly more advanced and flexible arrays are planned for the near term. These powerful instruments offer new opportunities for direct…

Instrumentation and Methods for Astrophysics · Physics 2018-02-07 C. Lonsdale , L. Benkevitch , I. Cairns , M. Crowley , P. Erickson , M. Knapp , K. Kozarev , F. Lind , P. McCauley , J. Morgan , D. Oberoi

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

A critical challenge in measuring the power spectrum of 21cm emission from cosmic reionization is compensating for the frequency dependence of an interferometer's sampling pattern, which can cause smooth-spectrum foregrounds to appear…

Instrumentation and Methods for Astrophysics · Physics 2015-06-04 Aaron R. Parsons , Jonathan C. Pober , James E. Aguirre , Christopher L. Carilli , Daniel C. Jacobs , David F. Moore

With the onset of large-scale astronomical surveys capturing millions of images, there is an increasing need to develop fast and accurate deconvolution algorithms that generalize well to different images. A powerful and accessible…

Instrumentation and Methods for Astrophysics · Physics 2022-11-18 Utsav Akhaury , Jean-Luc Starck , Pascale Jablonka , Frédéric Courbin , Kevin Michalewicz

Global 21cm cosmology aims to investigate the cosmic dawn and epoch of reionisation by measuring the sky averaged HI absorption signal, which requires, accurate modelling of, or correction for, the bright radio foregrounds and distortions…

Cosmology and Nongalactic Astrophysics · Physics 2023-01-18 Dominic Anstey , Eloy de Lera Acedo , Will Handley

Modern machine learning will allow for simulation-based inference from reionization-era 21cm observations at the Square Kilometre Array. Our framework combines a convolutional summary network and a conditional invertible network through a…

Cosmology and Nongalactic Astrophysics · Physics 2025-04-16 Benedikt Schosser , Caroline Heneka , Tilman Plehn

In order to study the "Cosmic Dawn" and the Epoch of Reionization with 21 cm tomography, we need to statistically separate the cosmological signal from foregrounds known to be orders of magnitude brighter. Over the last few years, we have…

We demonstrate a motion-free intensity diffraction tomography technique that enables direct inversion of 3D phase and absorption from intensity-only measurements for weakly scattering samples. We derive a novel linear forward model,…

Image and Video Processing · Electrical Eng. & Systems 2018-06-26 Ruilong Ling , Waleed Tahir , Hsing-Ying Lin , Hakho Lee , Lei Tian

We address the estimation of seismic wavefields by means of Multidimensional Deconvolution (MDD) for various redatuming applications. While offering more accuracy than conventional correlation-based redatuming methods, MDD faces challenges…

Numerical Analysis · Mathematics 2024-04-03 Daria Sushnikova , Matteo Ravasi , David Keyes

Wireless data transmission systems such as WiFi or Bluetooth emit coherent light - electromagnetic waves with precisely known amplitude and phase. Propagating in space, this radiation forms a hologram - a two-dimensional wavefront encoding…

Classical Physics · Physics 2017-05-10 Philipp Holl , Friedemann Reinhard

One of the main challenges for future 21 cm observations is to remove foregrounds which are several orders of magnitude more intense than the HI signal. We propose a new technique for removing foregrounds of the redshifted 21 cm…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-04 Jungyeon Cho , A. Lazarian , P. Timbie

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

To determine the epoch of reionization precisely and to reveal the property of inhomogeneous reionization are some of the most important topics of modern cosmology. Existing methods to investigate reionization which use cosmic microwave…

High Energy Astrophysical Phenomena · Physics 2020-02-26 Tomoki Terasaki , Daichi Tsuna , Toshikazu Shigeyama

We describe a new technique for turning scans of the microwave sky into intensity maps. The technique is based on a Fourier series analysis and is inspired by the lock-in deconvolution used in experiments which typically sweep the sky…

Astrophysics · Physics 2007-05-23 L. Piccirillo , G. Romeo , R. K. Schaefer , M. Limon

We consider the problem of mapping with ultra-high angular resolution using a space-ground radio interferometer with a space antenna in a high orbit,whose apogee height exceeds the radius of the Earth by a factor of ten. In this case, a…

Astrophysics · Physics 2009-11-13 Anisa T. Bajkova

This paper presents a case study from a single, six-hour observing period to illustrate the application of techniques developed for interferometric radio telescopes to the spectral analysis of observations of ionospheric fluctuations with…

Space Physics · Physics 2014-02-05 Joseph Helmboldt , Huib Intema