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Related papers: Centroiding Undersampled PSFs with a Lookup Table

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Point spread function (PSF) engineering is vital for precisely controlling the focus of light in computational imaging, with applications in neural imaging, fluorescence microscopy, and biophotonics. The PSF is derived from the magnitude of…

Optics · Physics 2025-04-22 Aleksey Valouev

We introduce a new algorithm for interpolating measurements of the point-spread function (PSF) using stars from many exposures. The principal components of the variation in the PSF pattern from multiple exposures are used to solve for…

Astrophysics · Physics 2007-05-23 Mike Jarvis , Bhuvnesh Jain

We report the use of a phase retrieval procedure based on maximum likelihood estimation (MLE) to produce an improved, experimentally calibrated model of a point spread function (PSF) for use in three-dimensional (3D) localization microscopy…

Optics · Physics 2017-05-30 Petar N. Petrov , Yoav Shechtman , W. E. Moerner

Reconstruction of the point spread function (PSF) plays an important role in many areas of astronomy, including photometry, astrometry, galaxy morphology, and shear measurement. The atmospheric and instrumental effects are the two main…

Instrumentation and Methods for Astrophysics · Physics 2024-04-25 Pedro Alonso , Jun Zhang , Cong Liu

Optimal error estimation is key to achieve accurate photometry and astrometry. Stellar fluxes and positions in high angular resolution images are typically measured with PSF fitting routines, such as StarFinder. However, the formal…

Instrumentation and Methods for Astrophysics · Physics 2022-08-12 E. Gallego-Cano , R. Schödel , A. T. Gallego-Calvente , A. M. Ghez

We propose an effective subspace selection scheme as a post-processing step to improve results obtained by sparse subspace clustering (SSC). Our method starts by the computation of stable subspaces using a novel random sampling scheme. Thus…

Computer Vision and Pattern Recognition · Computer Science 2016-05-30 Duc-Son Pham , Ognjen Arandjelovic , Svetha Venkatesh

We describe here a new full 2-D parameterization of the PSFs of the three XMM-Newton EPIC telescopes as a function of instrument, energy, off-axis angle and azimuthal angle, covering the whole field-of-view of the three EPIC detectors. It…

Instrumentation and Methods for Astrophysics · Physics 2015-05-30 A. M. Read , S. R. Rosen , R. D. Saxton , J. Ramirez

The PLATO space mission is designed to detect telluric planets in the habitable zone of solar type stars, and simultaneously characterise the host star using ultra high precision photometry. The photometry will be performed on board using…

Instrumentation and Methods for Astrophysics · Physics 2015-10-21 R-M. Ouazzani , J. J. Green , R. Samadi

The Vera C. Rubin Observatory's LSST Camera (LSSTCam) pixel response has been characterized using laboratory measurements with a grid of artificial stars. We quantify the contributions to photometry, centroid, point-spread function size,…

Pseudo-Centroid Clustering replaces the traditional concept of a centroid expressed as a center of gravity with the notion of a pseudo-centroid (or a coordinate free centroid) which has the advantage of applying to clustering problems where…

Data Structures and Algorithms · Computer Science 2016-11-04 Fred Glover

Exoplanetary transit and stellar oscillation surveys require a very high precision photometry. The instrumental noise has therefore to be minimized. First, we perform a semi-analytical model of different noise sources. We show that the…

Astrophysics · Physics 2015-05-13 Nicolas Crouzet , Tristan Guillot , Francois Fressin , Alain Blazit

Cosmic shear measurements rely on our ability to measure and correct the Point Spread Function (PSF) of the observations. This PSF is measured using stars in the field, which give a noisy measure at random points in the field. Using Wiener…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-13 A. Amara , A. Refregier , S. Paulin-Henriksson

Neglecting the second order corrections in weak lensing measurements can lead to a few percent uncertainties on cosmic shears, and becomes more important for cluster lensing mass reconstructions. Existing methods which claim to measure the…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-18 Jun Zhang

By measuring photoelectron tracks, the gas pixel detectors of the Imaging X-ray Polarimetry Explorer satellite provide estimates of the photon detection location and its electric vector position angle (EVPA). However, imperfections in…

Instrumentation and Methods for Astrophysics · Physics 2024-09-24 Jack T. Dinsmore , Roger W. Romani

Statistical modeling often involves identifying an optimal estimate to some underlying probability distribution known to satisfy some given constraints. I show here that choosing as estimate the centroid, or center of mass, of the set…

Methodology · Statistics 2013-10-11 Jonathan Landy

Learning phone types from phone instances has been a long-standing problem, while still being open. In this work, we revisit this problem in the context of self-supervised learning, and pose it as the problem of matching cluster centroids…

Computation and Language · Computer Science 2023-10-27 Gene-Ping Yang , Hao Tang

Inspired by recent work on neural subspaces and mode connectivity, we revisit parameter subspace sampling for shifted and/or interpolatable input distributions (instead of a single, unshifted distribution). We enforce a compressed geometric…

Machine Learning · Computer Science 2022-05-23 Siddhartha Datta , Nigel Shadbolt

Planned wide-field weak lensing surveys are expected to reduce the statistical errors on the shear field to unprecedented levels. In contrast, systematic errors like those induced by the convolution with the point spread function (PSF) will…

Cosmology and Nongalactic Astrophysics · Physics 2012-10-23 M. Gentile , F. Courbin , G. Meylan

Point spread function (PSF) reconstruction (PSF-R) is a well established technique to determine reliably and accurately the PSF from Adaptive Optics (AO) control loop data. We have successfully applied this technique to improve the…

Instrumentation and Methods for Astrophysics · Physics 2020-04-15 Olivier Beltramo-Martin , Antonino Marasco , Thierry Fusco , Davide Massari , Julien Milli , Giuliana Fiorentino , B. Neichel

X-ray cone-beam computed tomography (CT) has the notable features such as high efficiency and precision, and is widely used in the fields of medical imaging and industrial non-destructive testing, but the inherent imaging degradation…

Optics · Physics 2015-06-19 Hua Zhang , Kuidong Huang , Yikai Shi , Zhe Xu
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