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Reconstructing images from downsampled and noisy measurements, such as MRI and low dose Computed Tomography (CT), is a mathematically ill-posed inverse problem. We propose an easy-to-use reconstruction method based on Expectation…

Image and Video Processing · Electrical Eng. & Systems 2022-08-29 Robert G. Aykroyd , Kehinde Olobatuyi

In this paper we present a combined strategy for the retrieval of atmospheric profiles from infrared sounders. The approach considers the spatial information and a noise-dependent dimensionality reduction approach. The extracted features…

Signal Processing · Electrical Eng. & Systems 2020-12-11 David Malmgren-Hansen , Valero Laparra , Allan Aasbjerg Nielsen , Gustau Camps-Valls

(abridged) We examine the spatial and temporal stability of the HST ACS Wide Field Camera (WFC) point spread function (PSF) using the two square degree COSMOS survey. We show that stochastic aliasing of the PSF necessarily occurs during…

We present a general linear algorithm for measuring the surface mass density 1-\kappa from the observable reduced shear g=\gamma/(1-\kappa) in the strong lensing regime. We show that in general, the observed polarization field can be…

Astrophysics · Physics 2009-10-31 Ue-Li Pen

It is well known that Principal Component Analysis (PCA) is strongly affected by outliers and a lot of effort has been put into robustification of PCA. In this paper we present a new algorithm for robust PCA minimizing the trimmed…

Machine Learning · Statistics 2015-06-02 Anastasia Podosinnikova , Simon Setzer , Matthias Hein

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 probabilistic principal component analysis (PPCA), an observed vector is modeled as a linear transformation of a low-dimensional Gaussian factor plus isotropic noise. We generalize PPCA to tensors by constraining the loading operator to…

Statistics Theory · Mathematics 2025-10-23 Yaoming Zhen , Piotr Zwiernik

Removing the aberrations introduced by the Point Spread Function (PSF) is a fundamental aspect of astronomical image processing. The presence of noise in observed images makes deconvolution a nontrivial task that necessitates the use of…

Instrumentation and Methods for Astrophysics · Physics 2017-05-03 Samuel Farrens , Jean-Luc Starck , Fred Maurice Ngolè Mboula

Accurate blur estimation is essential for high-performance imaging across various applications. Blur is typically represented by the point spread function (PSF). In this paper, we propose a physics-informed PSF learning framework for…

Computer Vision and Pattern Recognition · Computer Science 2025-03-12 Liqun Chen , Yuxuan Li , Jun Dai , Jinwei Gu , Tianfan Xue

Dedicated 'Stage IV' observatories will soon observe the entire extragalactic sky, to measure the 'cosmic shear' distortion of galaxy shapes by weak gravitational lensing. To measure the apparent shapes of those galaxies, we present an…

Cosmology and Nongalactic Astrophysics · Physics 2022-02-08 Xiangchong Li , Yin Li , Richard Massey

This study presents a comprehensive end-to-end simulation analysis of the optical imaging performance of the China Survey Space Telescope (CSST) under in-orbit conditions. An integrated system model incorporating five static and two dynamic…

Instrumentation and Methods for Astrophysics · Physics 2025-11-11 Zhang Ban , Xiao-Bo Li , Xun Yang , Yu-Xi Jiang , Hong-Cai Ma , Wei Wang , Jin-guang Lv , Cheng-Liang Wei , De-Zi Liu , Guo-Liang Li , Chao Liu , Nan Li , Ran Li , Peng Wei

We present a study of weak lensing shear measurements for simulated galaxy images at radio wavelengths. We construct a simulation pipeline into which we can input galaxy images of known ellipticity, and with which we then simulate…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-15 Prina Patel , Filipe B. Abdalla , David J. Bacon , Barnaby Rowe , Oleg Smirnov , Rob J. Beswick

Nowadays, astronomers perform point spread function (PSF) fitting for most types of observational data. Interpolation of the PSF is often an intermediate step in such algorithms. In the case of the Multi-AO Imaging Camera for Deep…

Instrumentation and Methods for Astrophysics · Physics 2024-04-11 Mariia Demianenko , Joerg-Uwe Pott , Kai Polsterer

Functional principal component analysis (FPCA) is a key tool in the study of functional data, driving both exploratory analyses and feature construction for use in formal modeling and testing procedures. However, existing methods for FPCA…

Methodology · Statistics 2026-03-24 Caitrin Murphy , Eric Laber , Rhonda Merwin , Brian Reich , Jake Koerner

The Bayesian gravitational shear estimation algorithm developed by Bernstein and Armstrong (2014) can potentially be used to overcome multiplicative noise bias and recover shear using very low signal-to-noise ratio (S/N) galaxy images. In…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-19 Erin S. Sheldon

We study semiparametric factor models in high-dimensional panels where the factor loadings consist of a nonparametric component explained by observed covariates and an idiosyncratic component capturing unobserved heterogeneity. A key…

Methodology · Statistics 2025-12-09 Sijie Zheng

We present the results from the first public blind PSF reconstruction challenge, the GRavitational lEnsing Accuracy Testing 2010 (GREAT10) Star Challenge. Reconstruction of a spatially varying PSF, sparsely sampled by stars, at non-star…

Instrumentation and Methods for Astrophysics · Physics 2015-06-11 T. D. Kitching , B. Rowe , M. Gill , C. Heymans , R. Massey , D. Witherick , F. Courbin , K. Georgatzis , M. Gentile , D. Gruen , M. Kilbinger , G. L. Li , A. P. Mariglis , G. Meylan , A. Storkey , B. Xin

This paper presents a new method for the reconstruction of weak lensing mass maps. It uses the multiscale entropy concept, which is based on wavelets, and the False Discovery Rate which allows us to derive robust detection levels in wavelet…

Astrophysics · Physics 2009-11-10 Jean-Luc Starck , Sandrine Pires , Alexandre Refregier

Neural networks-based learning of the distribution of non-dispatchable renewable electricity generation from sources such as photovoltaics (PV) and wind as well as load demands has recently gained attention. Normalizing flow density models…

Machine Learning · Computer Science 2022-01-10 Eike Cramer , Alexander Mitsos , Raul Tempone , Manuel Dahmen

Images taken by space telescopes typically have a superb spatial resolution, but a relatively poor sampling rate due to the finite CCD pixel size. Beyond the Nyquist limit, it becomes uncertain how much the pixelation effect may affect the…

Cosmology and Nongalactic Astrophysics · Physics 2022-06-06 Zhi Shen , Jun Zhang , Hekun Li , Haoran Wang , Chengliang Wei , Guoliang Li , Xiaobo Li , Zhang Ban , Dan Yue