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The knowledge of the point spread function (PSF) of imaging instruments represents a fundamental requirement for astronomical observations. The Herschel PACS PSFs delivered by the instrument control centre are obtained from observations of…

Instrumentation and Methods for Astrophysics · Physics 2016-06-29 M. Bocchio , S. Bianchi , A. Abergel

The ill-posed problem of phase retrieval in optics, using one or more intensity measurements, has a multitude of applications using electromagnetic or matter waves. Many phase retrieval algorithms are computed on pixel arrays using discrete…

Image and Video Processing · Electrical Eng. & Systems 2022-09-21 J. A. Pollock , K. S. Morgan , L. C. P. Croton , M. K. Croughan , G. Ruben , N. Yagi , H. Sekiguchi , M. J. Kitchen

Accurate reconstruction of the spatial distributions of the Point Spread Function (PSF) is crucial for high precision cosmic shear measurements. Nevertheless, current methods are not good at recovering the PSF fluctuations of high spatial…

Cosmology and Nongalactic Astrophysics · Physics 2021-07-12 Tianhuan Lu , Jun Zhang , Fuyu Dong , Yingke Li , Dezi Liu , Liping Fu , Guoliang Li , Zuhui Fan

We present a new technique for monitoring microlensing activity even in highly crowded fields, and use this technique to place limits on low-mass MACHOs in the haloes of M31 and the Galaxy. Unlike present Galactic microlensing surveys, we…

Astrophysics · Physics 2009-09-28 Austin B. Tomaney , Arlin P. S. Crotts

We present extended point spread function (PSF) models for the Hyper Suprime-Cam Subaru Strategic Program Public Data Release 3 (HSC-SSP PDR3) in all $\textit{g,r,i,Z}$ and $\textit{Y}$-bands. Due to its 8.2m primary mirror and long…

Astrophysics of Galaxies · Physics 2024-05-17 L. P. Garate-Nuñez , A. S. G. Robotham , S. Bellstedt , L. J. M. Davies , C. Martínez-Lombilla

Even though the technology of adaptive optics (AO) is rapidly maturing, calibration of the resulting images remains a major challenge. The AO point-spread function (PSF) changes quickly both in time and position on the sky. In a typical…

In many radar scenarios, the radar target or the medium is assumed to possess randomly varying parts. The properties of a target are described by a random process known as the spreading function. Its second order statistics under the WSSUS…

Information Theory · Computer Science 2015-06-19 Götz E. Pfander , Pavel Zheltov

Image resolvability is the primary concern in imaging. This paper reports an estimation of the full width at half maximum of the point spread function from a Fourier domain plot of real sample images by neither using test objects, nor…

Elongation of the point spread function due to atmospheric dispersion becomes a severe problem for high resolution imaging instruments, if an atmospheric dispersion corrector is not present. In this work we report on a novel technique to…

Instrumentation and Methods for Astrophysics · Physics 2022-04-06 J. A. van den Born , W. Jellema , E. Dijkstra

This paper proposes a direct sampling method for the inverse problem of magnetic induction tomography (MIT). Our approach defines a class of point spread functions with explicit expressions, which are computed via inner products, leading to…

Numerical Analysis · Mathematics 2026-01-29 Junqing Chen , Chengzhe Jiang

The point-spread function (PSF) is a fundamental property of any astronomical instrument. In interferometers, differing array configurations combined with their $uv$ coverage, and various weighting schemes can produce an irregular but…

Instrumentation and Methods for Astrophysics · Physics 2023-10-20 Jack F. Radcliffe , R. J. Beswick , A. P. Thomson , A. Njeri , T. W. B. Muxlow

We consider the high-resolution imaging problem of 3D point source image recovery from 2D data using a method based on point spread function (PSF) engineering. The method involves a new technique, recently proposed by S.~Prasad, based on…

Signal Processing · Electrical Eng. & Systems 2019-06-13 Chao Wang , Raymond Chan , Mila Nikolova , Robert Plemmons , Sudhakar Prasad

The problem of adaptive sampling for estimating probability mass functions (pmf) uniformly well is considered. Performance of the sampling strategy is measured in terms of the worst-case mean squared error. A Bayesian variant of the…

Methodology · Statistics 2020-12-09 Dhruva Kartik , Neeraj Sood , Urbashi Mitra , Tara Javidi

An accurate model of the point spread function is required in order to estimate positions and brightnesses of stars in digitized images. The PSF of the Gaia space telescope is unusual due to the use of drift-scan mode and time-delayed…

Instrumentation and Methods for Astrophysics · Physics 2026-04-08 Nicholas Rowell , Michael Davidson , Nigel C. Hambly , Lennart Lindegren , Javier Castañeda , Claus Fabricius , Jose Hernández , Dafydd W. Evans

Adaptive optics (AO) restore the angular resolution of ground-based telescopes, but at the cost of delivering a time- and space-varying point spread function (PSF) with a complex shape. PSF knowledge is crucial for breaking existing limits…

Instrumentation and Methods for Astrophysics · Physics 2018-04-17 O. Beltramo-Martin , C. M. Correia , E. Mieda , B. Neichel , T. Fusco , G. Witzel , J. Lu , J. -P. Véran

Handling big data has largely been a major bottleneck in traditional statistical models. Consequently, when accurate point prediction is the primary target, machine learning models are often preferred over their statistical counterparts for…

Methodology · Statistics 2021-04-02 Arindam Fadikar , Stefan M. Wild , Jonas Chaves-Montero

We demonstrate the effectiveness of two techniques for using x-rays to evaluate the amount of charge diffusion in charge coupled devices (CCDs). We quantify the degree of charge diffusion with two parameters: sigma_d, the standard deviation…

Astrophysics · Physics 2009-11-11 S. A. Rodney , J. L. Tonry

We explore the impact of aperture size and shape on automotive camera systems for deep-learning-based tasks like traffic sign recognition and light state detection. A method is proposed to simulate optical effects using the point spread…

Computer Vision and Pattern Recognition · Computer Science 2025-01-17 Ofer Bar-Shalom , Tzvi Philipp , Eran Kishon

In positron emission tomography (PET) imaging, statistical iterative reconstruction (IR) techniques appear particularly promising since they can provide accurate system model. The system model matrix which describes the relationship between…

An empirical numerical model that includes nuclear absorption, multiple Coulomb scattering, and energy loss is presented in this work to calculate the transmission of the thick objects in high energy proton radiography, and in this…

Instrumentation and Detectors · Physics 2014-10-16 Zheng Na , Xu Hai-bo