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Image subtraction is essential for transient detection in time-domain astronomy. The point spread function (PSF), photometric scaling, and sky background generally vary with time and across the field-of-view for imaging data taken with…

Instrumentation and Methods for Astrophysics · Physics 2022-09-14 Lei Hu , Lifan Wang , Xingzhuo Chen , Jiawen Yang

Lensless cameras replace bulky optics with thin modulation masks, enabling compact imaging systems. However, existing methods rely on an idealized model that assumes a globally shift-invariant point spread function (PSF) and sufficiently…

Image and Video Processing · Electrical Eng. & Systems 2025-12-02 Yu Ren , Xiaoling Zhang , Xu Zhan , Xiangdong Ma , Yunqi Wang , Edmund Y. Lam , Tianjiao Zeng

Measuring a weak gravitational lensing signal to the level required by the next generation of space-based surveys demands exquisite reconstruction of the point-spread function (PSF). However, unresolved binary stars can significantly…

Instrumentation and Methods for Astrophysics · Physics 2017-11-01 T. Kuntzer , F. Courbin

The weak gravitational lensing is a powerful tool in modern cosmology. To accurately measure the weak lensing signal, one has to control the systematic bias to a small level. One of the most difficult problems is how to correct the smearing…

Cosmology and Nongalactic Astrophysics · Physics 2023-06-28 Q. Y. Liu , X. Z. Er , Z. H. Fan , D. Z. Liu , G. L. Li , C. L. Wei , Z. Ban , X. B. Li , D. Yue

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

The point-spread function (PSF) of an adaptive optics (AO) system is often poorly known. This ignorance can lead to significant systematic errors in photometry. Since the degree of AO correction is sensitive to the observing conditions:…

Astrophysics · Physics 2010-11-11 Christopher D. Sheehy , Nate McCrady , James R. Graham

The point spread function (PSF) is fundamental to any type of microscopy, most importantly so for single-molecule localization techniques, where the exact PSF shape is crucial for precise molecule localization at the nanoscale. However,…

Incoherently illuminated or luminescent objects give rise to a low-contrast speckle-like pattern when observed through a thin diffusive medium, as such a medium effectively convolves their shape with a speckle-like point spread function…

In weak lensing investigations, galaxy shapes are deconvolved for the effects of the point spread function (PSF) using stellar images. In this paper we use physical models of the telescope optics to understand the spatial variation of the…

Astrophysics · Physics 2008-10-02 Mike Jarvis , Paul Schechter , Bhuvnesh Jain

Point-spread-function (PSF) engineering is a powerful computational imaging techniques wherein a custom phase mask is integrated into an optical system to encode additional information into captured images. Used in combination with deep…

Computer Vision and Pattern Recognition · Computer Science 2023-03-31 Sachin Shah , Sakshum Kulshrestha , Christopher A. Metzler

Ground based optical telescopes are seriously affected by atmospheric turbulence induced aberrations. Understanding properties of these aberrations is important both for instruments design and image restoration methods development. Because…

Instrumentation and Methods for Astrophysics · Physics 2020-04-08 Peng Jia , Xuebo Wu , Yi Huang , Bojun Cai , Dongmei Cai

Point-spread-function (PSF) engineering is a well-established computational imaging technique that uses phase masks and other optical elements to embed extra information (e.g., depth) into the images captured by conventional CMOS image…

Computer Vision and Pattern Recognition · Computer Science 2024-06-14 Sachin Shah , Matthew Albert Chan , Haoming Cai , Jingxi Chen , Sakshum Kulshrestha , Chahat Deep Singh , Yiannis Aloimonos , Christopher Metzler

A wide field space-based imaging telescope is necessary to fully exploit the technique of observing dark matter via weak gravitational lensing. This first paper in a three part series outlines the survey strategies and relevant instrumental…

Astrophysics · Physics 2015-06-24 Jason Rhodes , Alexandre Refregier , Richard Massey , the SNAP Collaboration

Precise photometric and astrometric measurements on astronomical images require an accurate knowledge of the Point Spread Function (PSF). When the PSF cannot be modelled directly from the image, PSF-reconstruction techniques become the only…

Instrumentation and Methods for Astrophysics · Physics 2020-02-05 D. Massari , A. Marasco , O. Beltramo-Martin , J. Milli , G. Fiorentino , E. Tolstoy , F. Kerber

Due to limited size and imperfect of the optical components in a spectrometer, aberration has inevitably been brought into two-dimensional multi-fiber spectrum image in LAMOST, which leads to obvious spacial variation of the point spread…

Instrumentation and Methods for Astrophysics · Physics 2020-10-28 Jiali Xu , Qian Yin , Ping Guo , Xin Zheng

Observations close to the diffraction limit, with high Strehl ratios from Adaptive Optics (AO)-assisted instruments mounted on ground-based telescopes are a reality and will become even more widespread with the next generation instruments…

Instrumentation and Methods for Astrophysics · Physics 2023-10-23 Matteo Simioni , Carmelo Arcidiacono , Andrea Grazian , Marco Gullieuszik , Elisa Portaluri , Benedetta Vulcani , Roland Wagner , Anita Zanella

Imaging with a layered superlens is a spatial filtering operation characterized by the point spread function (PSF). We show that in the same optical system the image of a narrow sub-wavelength Gaussian incident field may be surprisingly…

Optics · Physics 2010-04-08 Rafal Kotynski , Tomasz Stefaniuk

Weak lensing by large-scale structure is an invaluable cosmological tool given that most of the energy density of the concordance cosmology is invisible. Several large ground-based imaging surveys will attempt to measure this effect over…

Cosmology and Nongalactic Astrophysics · Physics 2015-11-18 Eric M. Huff , Christopher M. Hirata , Rachel Mandelbaum , David Schlegel , Uros Seljak , Robert H. Lupton

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…

The combined PSF of the BFI and the SOT onboard the Hinode spacecraft is investigated. Observations of the Mercury transit from November 2006 and the solar eclipse(s) from 2007 are used to determine the PSFs of SOT for the blue, green, and…

Astrophysics · Physics 2009-11-13 Sven Wedemeyer-Böhm
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