English
Related papers

Related papers: A deconvolution map-making method for experiments …

200 papers

Many imaging problems require solving an inverse problem that is ill-conditioned or ill-posed. Imaging methods typically address this difficulty by regularising the estimation problem to make it well-posed. This often requires setting the…

Methodology · Statistics 2020-08-17 Ana F. Vidal , Valentin De Bortoli , Marcelo Pereyra , Alain Durmus

We present a method for extracting the expected cosmological 21-cm signal from the epoch of reionization, taking into account contaminating radiations and random instrumental noise. The method is based on the maximum a-posteriori…

Astrophysics · Physics 2008-12-21 Liron Gleser , Adi Nusser , Andrew J. Benson

We present a new method of removing PSF artifacts and improving the resolution of multidimensional data sources including imagers and spectrographs. Rather than deconvolution, which is translationally invariant, this method is based on…

The CLEAN deconvolution algorithm has well-known limitations due to the restriction of locating point source model components on a discretized grid. In this letter we demonstrate that these limitations are even more pronounced when applying…

Instrumentation and Methods for Astrophysics · Physics 2015-06-12 M. R. Bell , N. Oppermann , A. Crai , T. A. Enßlin

The forthcoming Planck experiment will provide high sensitivity polarization measurements that will allow us to further tighten the f_NL bounds from the temperature data. Monte Carlo simulations of non-Gaussian CMB maps have been used as a…

The interest of compressive sampling in ultrasound imaging has been recently extensively evaluated by several research teams. Following the different application setups, it has been shown that the RF data may be reconstructed from a small…

Computer Vision and Pattern Recognition · Computer Science 2015-12-07 Zhouye Chen , Adrian Basarab , Denis Kouamé

We introduce N+2 mapmaking as a novel approach to constructing maps in both intensity and polarization for multi-detector CMB data. The motivation behind this method is two-fold: Firstly, it provides individual temperature detector maps…

Instrumentation and Methods for Astrophysics · Physics 2025-09-29 M. Galloway , H. K. Eriksen , R. M. Sullivan , D. J. Watts , I. K. Wehus , L. Zapelli

Blind deconvolution has made significant progress in the past decade. Most successful algorithms are classified either as Variational or Maximum a-Posteriori ($MAP$). In spite of the superior theoretical justification of variational…

Computer Vision and Pattern Recognition · Computer Science 2014-06-17 Dilip Krishnan , Joan Bruna , Rob Fergus

This paper explores methods for constructing low multipole temperature and polarisation likelihoods from maps of the cosmic microwave background anisotropies that have complex noise properties and partial sky coverage. We use Planck 2018…

Cosmology and Nongalactic Astrophysics · Physics 2021-08-26 Roger de Belsunce , Steven Gratton , William Coulton , George Efstathiou

We develop a primal-dual algorithm that allows for one-step inversion of spectral CT transmission photon counts data to a basis map decomposition. The algorithm allows for image constraints to be enforced on the basis maps during the…

Medical Physics · Physics 2016-05-04 Rina Foygel Barber , Emil Y. Sidky , Taly Gilat Schmidt , Xiaochuan Pan

Real-time magnetic resonance imaging (MRI) methods generally shorten the measuring time by acquiring less data than needed according to the sampling theorem. In order to obtain a proper image from such undersampled data, the reconstruction…

Numerical Analysis · Mathematics 2013-12-05 Housen Li , Markus Haltmeier , Shuo Zhang , Jens Frahm , Axel Munk

We present an imaging algorithm for polarimetric interferometric data from radio telescopes. It is based on Bayesian statistics and thereby able to provide uncertainties and to incorporate prior information such as positivity of the total…

Instrumentation and Methods for Astrophysics · Physics 2025-04-02 Philipp Arras , Jakob Roth , Martin Reinecke , Richard A. Perley , Andrei Frolov , Rüdiger Westermann , Torsten A. Enßlin

We investigate the tolerance for systematic errors in lensing analysis applied to a patchwork map of Cosmic Microwave Background polarization. We focus on the properties of the individual polarization maps that comprise the patchwork and…

Cosmology and Nongalactic Astrophysics · Physics 2024-08-27 Ryo Nagata , Toshiya Namikawa

We present the first detailed case study using quadratic estimators (QE) to diagnose and remove systematics present in observed Cosmic Microwave Background (CMB) maps. In this work we focus on the temperature to polarization leakage. We use…

Cosmology and Nongalactic Astrophysics · Physics 2021-07-13 Joel Williams , Nialh McCallum , Aditya Rotti , Daniel Thomas , Richard Battye , Michael L. Brown

Measurements of the cosmic microwave background polarization are vulnerable to systematic contamination from beam imperfections. Because the unpolarized CMB T is orders of magnitude larger than the polarized E and B signals, even a tiny…

Instrumentation and Methods for Astrophysics · Physics 2019-11-12 Christopher Sheehy

We have performed a 70 billion dark-matter particles N-body simulation in a 2 $h^{-1}$ Gpc periodic box, using the concordance, cosmological model as favored by the latest WMAP3 results. We have computed a full-sky convergence map with a…

Marginal MAP inference involves making MAP predictions in systems defined with latent variables or missing information. It is significantly more difficult than pure marginalization and MAP tasks, for which a large class of efficient and…

Machine Learning · Computer Science 2015-11-10 Wei Ping , Qiang Liu , Alexander Ihler

Marine Controlled Source Electromagnetic (CSEM) is employed both in large-scale geophysical applications as well as within exploration of hydrocarbons and gas hydrates. Due to the diffusive character of the EM field only very low…

Geophysics · Physics 2022-11-08 Feng-Ping Li , Vemund Stenbekk Thorkildsen , Leiv-J Gelius , Jian-Hua Yue

In recent years, computational Time-of-Flight (ToF) imaging has emerged as an exciting and a novel imaging modality that offers new and powerful interpretations of natural scenes, with applications extending to 3D, light-in-flight, and…

Image and Video Processing · Electrical Eng. & Systems 2024-11-05 Ruiming Guo , Ayush Bhandari

We present the first application of the Cosmoglobe analysis framework by analyzing 9-year $\mathit{WMAP}$ time-ordered observations using similar machinery as BeyondPlanck utilizes for $\mathit{Planck}$ LFI. We analyze only the $\mathit…