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We generalize ERA method of PSF correction for more realistic situations. The method re-smears the observed galaxy image(galaxy image smeared by PSF) and PSF image by an appropriate function called Re-Smearing Function(RSF) to make new…

Cosmology and Nongalactic Astrophysics · Physics 2016-08-08 Yuki Okura , Toshifumi Futamase

NASA's Kepler, K2 and TESS missions employ Simple Aperture Photometry (SAP) to derive time-series photometry, where an aperture is estimated for each star, and pixels containing each star are summed to create a single light curve. This…

Instrumentation and Methods for Astrophysics · Physics 2021-08-25 Christina Hedges , Rodrigo Luger , Jorge Martinez Palomera , Jessie Dotson , Geert Barentsen

We present a detailed analysis of the point spread function (PSF) of JWST NIRCam imaging in eight filters: F070W, F115W, F150W, F200W, F277W, F356W, F444W, and F480M, using publicly available data. Spatial variations in the PSF FWHM…

Astrophysics of Galaxies · Physics 2023-04-28 Ming-Yang Zhuang , Yue Shen

The control of systematic effects when measuring galaxy shapes is one of the main challenges for cosmic shear analyses. In this context, we study the fundamental limitations on shear accuracy due to the measurement of the Point Spread…

Astrophysics · Physics 2009-11-13 S. Paulin-Henriksson , A. Amara , L. Voigt , A. Refregier , S. L. Bridle

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…

Phase retrieval, i.e. the reconstruction of phase information from intensity information, is a central problem in many optical systems. Here, we demonstrate that a deep residual neural net is able to quickly and accurately perform this task…

Image and Video Processing · Electrical Eng. & Systems 2020-01-29 Leonhard MÖckl , Petar N. Petrov , W. E. Moerner

We present results of the point spread function (PSF) calibration of the hard X-ray optics of the Nuclear Spectroscopic Telescope Array (NuSTAR). Immediately post-launch, NuSTAR has observed bright point sources such as Cyg X-1, Vela X-1,…

We introduce a new framework for point-spread function (PSF) subtraction based on the spatio-temporal variation of speckle noise in high-contrast imaging data where the sampling timescale is faster than the speckle evolution timescale. One…

Instrumentation and Methods for Astrophysics · Physics 2023-01-23 Briley L. Lewis , Michael P. Fitzgerald , Rupert H. Dodkins , Kristina K. Davis , Jonathan Lin

Current and future imaging surveys will measure cosmic shear with a statistical precision that demands a deeper understanding of potential systematic biases in galaxy shape measurements than has been achieved to date. We investigate the…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-18 J. E. Meyers , P. R. Burchat

An important factor which affects performance of solar adaptive optics (AO) systems is the accuracy of tracking an extended object in the wavefront sensor. The accuracy of a centre-ofmass approach to image shift measurement depends on the…

Instrumentation and Methods for Astrophysics · Physics 2015-08-21 M. J. Townson , A. Kellerer , C. D. Saunter

Phase aberration is an inherent side effect of ultrasound imaging due to the speed of sound inhomogeneity nature of human tissues, resulting in focusing error and reduced image contrast. This work introduces a phase aberration correction…

Signal Processing · Electrical Eng. & Systems 2023-08-29 Wei-Hsiang Shen , Yu-An Lin , Pai-Chi Li , Meng-Lin Li

Field distortion is widespread in imaging systems. If it cannot be measured and corrected well, it will affect the accuracy of photogrammetry. To this end, we proposed a general field distortion model based on Fredholm integration, which…

Image and Video Processing · Electrical Eng. & Systems 2022-05-19 Yunqi Sun , Jianfeng Zhou

A sample of the brightest point-like sources observed with the ROSAT-HRI were analysed to asses on the intrinsic shape of the ROSAT-HRI Point Spread Function (PSF). Almost all of the HRI observations collected during the ROSAT lifetime are…

Astrophysics · Physics 2007-05-23 Peter Predehl , Almudena Prieto

We demonstrate that artificial bipolar structure can be detected using spectro-astrometry when the point spread function (PSF) of a point source suffers distortion in a relatively wide slit. Spectro-astrometry is a technique which allows us…

Astrophysics · Physics 2009-11-13 E. Brannigan , M. Takami , A. Chrysostomou , J. Bailey

Intra-pixel sensitivity variations (IPSVs) in charge-coupled devices (CCDs) and complementary metal-oxide-semiconductor (CMOS) detectors constitute a significant source of astrometric error for undersampled stellar observations. Since…

Instrumentation and Methods for Astrophysics · Physics 2026-03-12 Peipei Wang , Zihuang Cao , Chao Liu , Peng Wei , Xin Zhang , Jialu Nie

In gamma ray astronomy muon events have a distinct feature of casting ring-like images on the sensor plane, thus forming a well known signal class for Cherenkov telescopes. These ring-like images can then be used to deduce the optical point…

Instrumentation and Methods for Astrophysics · Physics 2020-01-22 Laurits Tani

A critical analysis and comparison of different methods for obtaining point spread function (PSF) photometry are carried out. Deep ACS observations of NGC3370 were reduced using four distinct approaches. These reductions explore a number of…

Astrophysics of Galaxies · Physics 2023-03-08 In Sung Jang

Cosmological weak lensing measurements rely on a precise measurement of the shear two-point correlation function (2PCF) along with a deep understanding of systematics that affect it. In this work, we demonstrate a general framework for…

We present a semi-blind, spatially-variant deconvolution technique aimed at optical microscopy that combines a local estimation step of the point spread function (PSF) and deconvolution using a spatially variant, regularized Richardson-Lucy…

Computer Vision and Pattern Recognition · Computer Science 2019-05-21 Adrian Shajkofci , Michael Liebling