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Scanning Kelvin probe microscopy (SKPM) is a powerful technique for investigating the electrostatic properties of material surfaces, enabling the imaging of variations in work function, topology, surface charge density, or combinations…

Applied Physics · Physics 2024-07-26 Isaac C. D. Lenton , Felix Pertl , Lubuna Shafeek , Scott R. Waitukaitis

The spatial resolution of astronomical images is limited by atmospheric turbulence and diffraction in the telescope optics, resulting in blurred images. This makes it difficult to accurately measure the brightness of blended objects because…

Instrumentation and Methods for Astrophysics · Physics 2023-05-31 Kevin Michalewicz , Martin Millon , Frédéric Dux , Frédéric Courbin

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

Localization microscopy is an imaging technique in which the positions of individual nanoscale point emitters (e.g. fluorescent molecules) are determined at high precision from their images. This is the key ingredient in…

Image and Video Processing · Electrical Eng. & Systems 2020-10-01 Elias Nehme , Daniel Freedman , Racheli Gordon , Boris Ferdman , Lucien E. Weiss , Onit Alalouf , Reut Orange , Tomer Michaeli , Yoav Shechtman

We present the point-spread function (PSF) of the Extreme Ultraviolet High-Resolution Imager (HRIEUV) onboard Solar Orbiter, which observes the Sun at 174 Angstrom. This PSF provides a quantitative description of light diffracted by the…

Astrometric precision and knowledge of the point spread function are key ingredients for a wide range of astrophysical studies including time-delay cosmography in which strongly lensed quasar systems are used to determine the Hubble…

Instrumentation and Methods for Astrophysics · Physics 2021-09-22 Geoff C. -F. Chen , Tommaso Treu , Christopher D. Fassnacht , Sam Ragland , Thomas Schmidt , Sherry H. Suyu

Smoothing is omnipresent in astronomy, because almost always measurements performed at discrete positions in the sky need to be interpolated into a smooth map for subsequent analysis. Still, the statistical properties of different…

Astrophysics · Physics 2009-11-07 Marco Lombardi

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

Point-spread function of the probe forming optics ($PSF_{optics} $) is reported for the first time in an uncorrected (without multipole correctors) scanning electron microscope (SEM). In an SEM, the electron probe information is lost as the…

Materials Science · Physics 2024-07-02 Surya Kamal , Richard K. Hailstone

We present a method for speckle holography that is optimised for crowded fields. Its two key features are an iterativ improvement of the instantaneous Point Spread Functions (PSFs) extracted from each speckle frame and the (optional)…

Instrumentation and Methods for Astrophysics · Physics 2015-05-30 R. Schoedel , S. Yelda , A. Ghez , J. H. V. Girard , L. Labadie , R. Rebolo , A. Perez-Garrido , M. R. Morris

We present the theoretical and analytical bases of optimal techniques to measure weak gravitational shear from images of galaxies. We first characterize the geometric space of shears and ellipticity, then use this geometric interpretation…

Astrophysics · Physics 2009-11-06 G. M. Bernstein , M. Jarvis

Direct imaging of exoplanets is limited by bright quasi-static speckles in the point spread function (PSF) of the central star. This limitation can be reduced by subtraction of reference PSF images. We have developed an algorithm to…

Astrophysics · Physics 2011-02-11 David Lafreniere , Christian Marois , Rene Doyon , Daniel Nadeau , Etienne Artigau

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

Modern design of complex optical systems relies heavily on computational tools. These typically utilize geometrical optics as well as Fourier optics, which enables the use of diffractive elements to manipulate light with features on the…

Optics · Physics 2022-07-27 Boris Ferdman , Alon Saguy , Onit Alalouf , Yoav Shechtman

Forthcoming space-based observations will require high-quality point-spread function (PSF) models for weak gravitational lensing measurements. One approach to generating these models is using a wavefront model based on the known telescope…

Instrumentation and Methods for Astrophysics · Physics 2020-06-29 Bryan R. Gillis , Tim Schrabback , Ole Marggraf , Rachel Mandelbaum , Richard Massey , Jason Rhodes , Andy Taylor

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

We describe a method for deriving the position and flux of point and compact sources observed by a scanning survey mission. Results from data simulated to test our method are presented, which demonstrate that at least a 10-fold improvement…

Instrumentation and Methods for Astrophysics · Physics 2015-05-13 F. van Leeuwen , A. N. Morgan , D. L. Harrison

Image subtraction in astronomy is a tool for transient object discovery and characterization, particularly useful in wide fields, and is well suited for moving or photometrically varying objects such as asteroids, extra-solar planets and…

Instrumentation and Methods for Astrophysics · Physics 2013-01-09 Steven Hartung

Accessing the point-spread function (PSF) of a complex optical system is important for a variety of imaging applications. However, placing an invasive point source is often impractical, and estimating it blindly with multiple frames is slow…

Optics · Physics 2020-09-23 Tengfei Wu , Jonathan Dong , Sylvain Gigan

Photometric surveys require precise point spread function (PSF) characterization, as it varies across filters and is crucial for accurate photometry and low surface brightness (LSB) studies. However, the small PSF size provided by default…

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