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Related papers: LOFAR Sparse Image Reconstruction

200 papers

Compressive sensing(CS) has drawn much attention in recent years due to its low sampling rate as well as high recovery accuracy. As an important procedure, reconstructing a sparse signal from few measurement data has been intensively…

Information Theory · Computer Science 2018-06-25 Yicong He , Fei Wang , Shiyuan Wang , Badong Chen

This paper introduces a new method for learning and inferring sparse representations of depth (disparity) maps. The proposed algorithm relaxes the usual assumption of the stationary noise model in sparse coding. This enables learning from…

Computer Vision and Pattern Recognition · Computer Science 2015-05-20 Ivana Tosic , Bruno A. Olshausen , Benjamin J. Culpepper

The sparse layouts of radio interferometers result in an incomplete sampling of the sky in Fourier space which leads to artifacts in the reconstructed images. Cleaning these systematic effects is essential for the scientific use of…

Instrumentation and Methods for Astrophysics · Physics 2023-07-27 Kevin Schmidt , Felix Geyer , Stefan Fröse , Paul-Simon Blomenkamp , Marcus Brüggen , Francesco de Gasperin , Dominik Elsässer , Wolfgang Rhode

Synthetic aperture sonar (SAS) image resolution is constrained by waveform bandwidth and array geometry. Specifically, the waveform bandwidth determines a point spread function (PSF) that blurs the locations of point scatterers in the…

Computer Vision and Pattern Recognition · Computer Science 2021-12-17 Albert Reed , Thomas Blanford , Daniel C. Brown , Suren Jayasuriya

Fourier ptychographic (FP) microscope is a coherent imaging method that can synthesize an image with a higher bandwidth using multiple low-bandwidth images captured at different spatial frequency regions. The method's demand for multiple…

Optics · Physics 2016-03-25 Jaebum Chung , Hangwen Lu , Xiaoze Ou , Haojiang Zhou , Changhuei Yang

We propose a new technique for radio interferometry to obtain super-resolution full polarization images in all four Stokes parameters using sparse modeling. The proposed technique reconstructs the image in each Stokes parameter from the…

The LOw FRequency ARray - LOFAR is a new radio telescope that is moving the science of radio pulsars and transients into a new phase. Its design places emphasis on digital hardware and flexible software instead of mechanical solutions.…

Instrumentation and Methods for Astrophysics · Physics 2012-07-03 Maciej Serylak , Aris Karastergiou , Chris Williams , Wes Armour , LOFAR Pulsar Working Group

In this work, we propose using camera arrays coupled with coherent illumination as an effective method of improving spatial resolution in long distance images by a factor of ten and beyond. Recent advances in ptychography have demonstrated…

Computer Vision and Pattern Recognition · Computer Science 2015-11-29 Jason Holloway , M. Salman Asif , Manoj Kumar Sharma , Nathan Matsuda , Roarke Horstmeyer , Oliver Cossairt , Ashok Veeraraghavan

We briefly consider some design aspects of aperture arrays for use in radio astronomy, particularly contrasting the performance of dense and sparse aperture arrays. Recent insights have emerged in the final design phase of LOFAR which…

Astrophysics · Physics 2007-05-23 Robert Braun , Wim van Cappellen

The advent of large aperture arrays, such as the ones currently under construction for the SKA project, allows for observing the Universe in the radio-spectrum at unprecedented resolution and sensitivity. To process the enormous amounts of…

Instrumentation and Methods for Astrophysics · Physics 2025-07-31 S. Wang , S. Mignot , S. Prunet , L. Di Mascolo , M. Spinelli , A. Ferrari

We present a physics-informed deep learning framework to address common limitations in Confocal Laser Scanning Microscopy (CLSM), such as diffraction limited resolution, noise, and undersampling due to low laser power conditions. The…

Materials Science · Physics 2025-01-27 Zaheer Ahmad , Junaid Shabeer , Usman Saleem , Tahir Qadeer , Abdul Sami , Zahira El Khalidi , Saad Mehmood

The method of superposition is proposed in combination with a sparse $\ell_1$ optimisation algorithm with the aim of finding a sparse basis to accurately reconstruct the structural vibrations of a radiating object from a set of acoustic…

Computational Physics · Physics 2016-01-20 Nadia M. Abusag , David J. Chappell

Modern radio telescopes, such as the Square Kilometre Array (SKA), will probe the radio sky over large fields-of-view, which results in large w-modulations of the sky image. This effect complicates the relationship between the measured…

Instrumentation and Methods for Astrophysics · Physics 2017-07-14 Arwa Dabbech , Laura Wolz , Luke Pratley , Jason D. McEwen , Yves Wiaux

Circular Synthetic aperture sonars (CSAS) capture multiple observations of a scene to reconstruct high-resolution images. We can characterize resolution by modeling CSAS imaging as the convolution between a scene's underlying point…

Image and Video Processing · Electrical Eng. & Systems 2023-06-28 Albert Reed , Thomas Blanford , Daniel C. Brown , Suren Jayasuriya

The LOw Frequency Array, LOFAR, is a next generation radio telescope with its core in the Netherlands and elements distributed throughout Europe. It has exceptional collecting area and wide bandwidths at frequencies from 10 MHz up to 250…

High Energy Astrophysical Phenomena · Physics 2015-06-11 Vladislav Kondratiev , Ben Stappers , the LOFAR Pulsar Working Group

We present a novel approach for recovering a sparse signal from cross-correlated data. Cross-correlations naturally arise in many fields of imaging, such as optics, holography and seismic interferometry. Compared to the sparse signal…

Signal Processing · Electrical Eng. & Systems 2021-04-28 Miguel Moscoso , Alexei Novikov , George Papanicolaou , Chrysoula Tsogka

In this paper we aim to tackle the problem of reconstructing a high-resolution image from a single low-resolution input image, known as single image super-resolution. In the literature, sparse representation has been used to address this…

Computer Vision and Pattern Recognition · Computer Science 2016-03-23 Mohammad Rostami , Zhou Wang

An inverse source reconstruction (ISR) based 3-D near-field (NF) passive radar microwave imaging method utilizing modulated signals is presented. The modulated signals from a non-cooperative transmitter are scattered by the targets of…

Image and Video Processing · Electrical Eng. & Systems 2026-05-06 Quanfeng Wang , Alexander H. Paulus , Thomas F. Eibert

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

It has previously been demonstrated that model-based reconstruction methods relying on a priori knowledge of the imaging point spread function (PSF) coupled to sparsity priors on the object to image can provide super-resolution in…

Image and Video Processing · Electrical Eng. & Systems 2019-10-02 Sergey Vilov , Bastien Arnal , Eliel Hojman , Yonina C. Eldar , Ori Katz , Emmanuel Bossy