English
Related papers

Related papers: Iterative map-making for scanning experiments

200 papers

Estimation of quantum states is one of the most important steps in any quantum information processing experiment. A naive reconstruction of the density matrix from experimental measurements can often give density matrices which are not…

Quantum Physics · Physics 2016-08-24 Harpreet Singh , Arvind , Kavita Dorai

We discuss an approach to the component separation of microwave, multi-frequency sky maps as those typically produced from Cosmic Microwave Background (CMB) Anisotropy data sets. The algorithm is based on the two step, parametric,…

Astrophysics · Physics 2009-06-23 R. Stompor , S. Leach , F. Stivoli , C. Baccigalupi

Multiplicative noise arises in inverse problems when, for example, uncertainty on measurements is proportional to the size of the measurement itself. The likelihood that arises is hence more complicated than that from additive noise. We…

Statistics Theory · Mathematics 2019-11-01 Matthew M. Dunlop

Iterative algorithms are widely used in digital signal processing applications. With the case study of radio astronomy calibration processing, this work contributes towards revealing and exploiting the intrinsic error resilience of…

Signal Processing · Electrical Eng. & Systems 2025-02-21 G. A. Gillani , A. Krapukhin , A. B. J. Kokkeler

We propose a method to extract the projected power spectrum of density perturbations from the distortions in the cosmic microwave background (CMB). The distortions are imprinted onto the CMB by the gravitational lensing effect and can be…

Astrophysics · Physics 2009-10-31 Uros Seljak , Matias Zaldarriaga

Adaptive measurements were recently shown to significantly improve the performance of quantum state tomography. Utilizing information about the system for the on-line choice of optimal measurements allows to reach the ultimate bounds of…

Estimation of the sky signal from sequences of time ordered data is one of the key steps in Cosmic Microwave Background (CMB) data analysis, commonly referred to as the map-making problem. Some of the most popular and general methods…

Cosmology and Nongalactic Astrophysics · Physics 2014-12-16 Mikolaj Szydlarski , Laura Grigori , Radek Stompor

We consider estimating a piecewise-constant image, or a gradient-sparse signal on a general graph, from noisy linear measurements. We propose and study an iterative algorithm to minimize a penalized least-squares objective, with a penalty…

Machine Learning · Statistics 2019-05-16 Sheng Xu , Zhou Fan

In this paper the elicitation of probabilities from human experts is considered as a measurement process, which may be disturbed by random 'measurement noise'. Using Bayesian concepts a second order probability distribution is derived…

Artificial Intelligence · Computer Science 2013-04-05 Gerhard Paaß

We discuss a method for a model independent reconstruction of the CMB temperature fluctuation power spectrum on small and intermediate scales that is geared to individual experiments. The importance of off-diagonal correlations for…

Astrophysics · Physics 2009-09-25 Martin White

The log-likelihood of a generative model often involves both positive and negative terms. For a temporal multivariate point process, the negative term sums over all the possible event types at each time and also integrates over all the…

Machine Learning · Computer Science 2020-11-03 Hongyuan Mei , Tom Wan , Jason Eisner

This paper deals with impulse noise removal from color images. The proposed noise removal algorithm employs a novel approach with morphological filtering for color image denoising; that is, detection of corrupted pixels and removal of the…

Computer Vision and Pattern Recognition · Computer Science 2017-07-12 Alexey Ruchay , Vitaly Kober

Observations of the Cosmic Microwave Background (CMB) provide increasingly accurate information about the structure of the Universe at the recombination epoch. Most of this information is encoded in the angular power spectrum of the CMB.…

Astrophysics · Physics 2011-08-01 G. Faÿ , F. Guilloux , M. Betoule , J. -F. Cardoso , J. Delabrouille , M. Le Jeune

The success of ptychographic imaging experiments strongly depends on achieving high signal-to-noise ratio. This is particularly important in nanoscale imaging experiments when diffraction signals are very weak and the experiments are…

Image and Video Processing · Electrical Eng. & Systems 2019-06-10 Huibin Chang , Pablo Enfedaque , Jie Zhang , Juliane Reinhardt , Bjoern Enders , Young-Sang Yu , David Shapiro , Christian G. Schroer , Tieyong Zeng , Stefano Marchesini

Pursuing the original idea proposed in our previous paper (Paper I), we improve the method to determine the shape of the initial curvature perturbation spectrum $P(k)$ from the CMB data. The thickness of the last scattering surface (LSS)…

Astrophysics · Physics 2009-10-09 Makoto Matsumiya , Misao Sasaki , Jun'ichi Yokoyama

The maximum a-posteriori (MAP) perturbation framework has emerged as a useful approach for inference and learning in high dimensional complex models. By maximizing a randomly perturbed potential function, MAP perturbations generate unbiased…

Machine Learning · Computer Science 2013-10-17 Francesco Orabona , Tamir Hazan , Anand D. Sarwate , Tommi Jaakkola

The presence of interference renders classic Fisher randomization tests infeasible due to nuisance unknowns. To address this issue, we propose imputing the nuisance unknowns and computing Fisher randomization p-values multiple times, then…

Methodology · Statistics 2024-11-14 Tingxuan Han , Ke Zhu , Hanzhong Liu , Ke Deng

We revisit the impact of finite time responses of bolometric detectors used for deep observations of the cosmic microwave background (CMB). Until now, bolometer transfer functions have been accounted for through a two-step procedure by…

Cosmology and Nongalactic Astrophysics · Physics 2024-08-21 A. Basyrov , N. O. Stutzer , J. G. S. Lunde , H. K. Eriksen , E. Gjerløw , D. J. Watts , I. K. Wehus

We consider the imaging of cosmic strings by using Cosmic Microwave Background (CMB) data. Mathematically, we study the inversion of an X-ray transform in Lorentzian geometry, called the light ray transform. The inverse problem is highly…

Numerical Analysis · Mathematics 2024-05-06 Julianne Chung , Lucas Onisk , Yiran Wang

Inverse problems are of great importance in astrophysics for deriving information about the physical characteristics of hot optically thin plasma sources from their EUV and X-ray spectra. We describe and test an iterative method developed…

Solar and Stellar Astrophysics · Physics 2014-01-24 F. F. Goryaev , S. Parenti , A. M. Urnov , S. N. Oparin , J. -F. Hochedez , F. Reale
‹ Prev 1 8 9 10 Next ›