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Subspace recycling techniques have been used quite successfully for the acceleration of iterative methods for solving large-scale linear systems. These methods often work by augmenting a solution subspace generated iteratively by a known…

Numerical Analysis · Mathematics 2021-05-18 Ronny Ramlau , Kirk M. Soodhalter , Victoria Hutterer

We present the generalized iterative residual fitting (IRF) for the computation of the spherical harmonic transform (SHT) of band-limited signals on the sphere. The proposed method is based on the partitioning of the subspace of…

Information Theory · Computer Science 2017-09-11 Usama Elahi , Zubair Khalid , Rodney A. Kennedy , Jason D. McEwen

We present a novel method for reconstructing weak lensing mass or convergence maps as a probe to study non-Gaussianities in the cosmic density field. While previous surveys have relied on a flat-sky approximation, the forthcoming stage IV…

Cosmology and Nongalactic Astrophysics · Physics 2023-02-03 Vanshika Kansal

We describe a new algorithm to solve a particular phase retrieval problem, that has wide applications in audio processing: the reconstruction of a function from its scalogram, that is from the modulus of its wavelet transform. It is a…

Optimization and Control · Mathematics 2017-04-11 Irène Waldspurger

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 propose a sampling scheme that can perfectly reconstruct a collection of spikes on the sphere from samples of their lowpass-filtered observations. Central to our algorithm is a generalization of the annihilating filter method, a tool…

Information Theory · Computer Science 2016-01-20 Ivan Dokmanic , Yue M. Lu

The Tianlai Cylinder Pathfinder Array consists of three adjacent cylindrical reflectors fixed on the ground, each 40 meters long and 15 meters wide, with the cylinder axis oriented along the North-South (N-S)direction. Dual linear…

Instrumentation and Methods for Astrophysics · Physics 2025-08-05 Jixia Li , Nanben Suo , Shenzhe Xu , Shijie Sun , Shifan Zuo , Yougang Wang , Fengquan Wu , Juyong Zhang , Peter Timbie , Reza Ansari , Albert Stebbins , Xuelei Chen

We consider an inverse scattering problem for time-harmonic acoustic or electromagnetic waves. The goal is to localize several small penetrable objects embedded inside an otherwise homogeneous background medium from observations of far…

Numerical Analysis · Mathematics 2017-04-05 Roland Griesmaier , Christian Schmiedecke

In a recent paper (Brown & Battye 2011), we proposed the use of integrated polarization measurements of background galaxies in radio weak gravitational lensing surveys and investigated the potential impact on the statistical measurement of…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-27 Michael L. Brown , Richard A. Battye

Diffusion models have recently emerged as a promising framework for Image Restoration (IR), owing to their ability to produce high-quality reconstructions and their compatibility with established methods. Existing methods for solving noisy…

Computer Vision and Pattern Recognition · Computer Science 2025-11-21 Kyungsung Lee , Donggyu Lee , Myungjoo Kang

This letter considers the problem of recovering a positive stream of Diracs on a sphere from its projection onto the space of low-degree spherical harmonics, namely, from its low-resolution version. We suggest recovering the Diracs via a…

Information Theory · Computer Science 2015-10-28 Tamir Bendory , Yonina C. Eldar

Reconstructing images of the radio sky from incomplete Fourier information is a key challenge in radio astronomy. In this work, we present a method for radio interferometric image reconstruction using a data-driven prior for the radio sky…

Instrumentation and Methods for Astrophysics · Physics 2026-04-06 Michel Morales , Emma Tolley , Remi Poitevineau

Hyperspectral imaging systems based on multiple-beam interference (MBI), such as Fabry-Perot interferometry, are attracting interest due to their compact design, high throughput, and fine resolution. Unlike dispersive devices, which measure…

Signal Processing · Electrical Eng. & Systems 2024-10-30 Mohamad Jouni , Daniele Picone , Mauro Dalla Mura

Environmental scene reconstruction is of great interest for autonomous robotic applications, since an accurate representation of the environment is necessary to ensure safe interaction with robots. Equally important, it is also vital to…

Signal Processing · Electrical Eng. & Systems 2022-06-23 Cristian J. Vaca-Rubio , Roberto Pereira , Xavier Mestre , David Gregoratti , Zheng-Hua Tan , Elisabeth de Carvalho , Petar Popovski

The image-based rendering approach using Shearlet Transform (ST) is one of the state-of-the-art Densely-Sampled Light Field (DSLF) reconstruction methods. It reconstructs Epipolar-Plane Images (EPIs) in image domain via an iterative…

Signal Processing · Electrical Eng. & Systems 2023-07-19 Yuan Gao , Robert Bregovic , Atanas Gotchev

An automated approach to reconstruct spherical Kikuchi maps from experimentally collected electron backscatter diffraction patterns and overlay each pattern onto its corresponding position on a simulated Kikuchi sphere is presented in this…

Materials Science · Physics 2019-07-10 Chaoyi Zhu , Kevin Kaufmann , Kenneth Vecchio

Combining the visibilities measured by an interferometer to form a cosmological power spectrum is a complicated process. In a delay-based analysis, the mapping between instrumental and cosmological space is not a one-to-one relation.…

The Tianlai experiment is dedicated to the observation of large scale structures (LSS) by the 21 cm intensity mapping technique. In this paper we make forecasts on its capability at observing or constraining the dark energy parameters and…

Cosmology and Nongalactic Astrophysics · Physics 2014-12-22 Yidong Xu , Xin Wang , Xuelei Chen

We present an algorithm for resampling a function from its values on a non-Cartesian grid onto a Cartesian grid. This problem arises in many applications such as MRI, CT, radio astronomy and geophysics. Our algorithm, termed SParse Uniform…

Information Theory · Computer Science 2016-03-17 Amir Kiperwas , Daniel Rosenfeld , Yonina C. Eldar