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Thick, fully depleted charge-coupled devices (CCDs) are known to exhibit non-linear behavior at high signal levels due to the dynamic behavior of charges collecting in the potential wells of pixels, called the brighter-fatter effect (BFE).…

Reduction of images and science analysis from ground-based telescopes such as the LSST requires detailed knowledge of the PSF of the image, which includes components attributable to the instrument as well as components attributable to the…

Instrumentation and Methods for Astrophysics · Physics 2017-04-26 Craig Lage , Andrew Bradshaw , J. Anthony Tyson

Upcoming and current large astronomical survey experiments often seek to constrain cosmological parameters via measurements of subtle effects such as weak lensing, which can only be measured statistically. In these cases, instrumental…

Instrumentation and Methods for Astrophysics · Physics 2015-06-11 C. W. Walter

The brighter-fatter effect affects all CCD sensors to various degrees. Deep-depleted thick sensors are seriously affected and the measurement of galaxy shapes for cosmic shear measurements requires an accurate correction of the effect in…

Instrumentation and Methods for Astrophysics · Physics 2023-02-22 Pierre Astier , Nicolas Regnault

The "brighter-fatter" (BF) effect is a phenomenon (originally discovered in charge coupled devices) in which the size of the detector point spread function (PSF) increases with brightness. We present, for the first time, laboratory…

Instrumentation and Methods for Astrophysics · Physics 2018-05-16 Andrés A. Plazas , Charles A. Shapiro , R. Smith , E. Huff , J. Rhodes

We present evidence that spots imaged using astronomical CCDs do not exactly scale with flux: bright spots tend to be broader than faint ones, using the same illumination pattern. We measure that the linear size of spots or stars, of…

Instrumentation and Methods for Astrophysics · Physics 2015-06-18 P. Antilogus , P. Astier , P. Doherty , A. Guyonnet , N. Regnault

Doing quantitative computed tomography (CT) using Bremsstrahlung sources requires an estimate of the spectrum emitted by the X-ray source. One method of beam hardening correction (BHC), as described by Lifton[1], first uses transmission…

Medical Physics · Physics 2025-08-13 Nikhil Deshmukh

The 3.2 gigapixel LSST camera, an array of 189 thick fully-depleted CCDs, will repeatedly image the southern sky and accomplish a wide variety of science goals. However, its trove of tens of billions of object images implies stringent…

Instrumentation and Methods for Astrophysics · Physics 2018-08-03 Andrew K. Bradshaw , Craig Lage , J. Anthony Tyson

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

Charge-coupled devices (CCDs) are widely used in astronomy to carry out a variety of measurements, such as for flux or shape of astrophysical objects. The data reduction procedures almost always assume that ther esponse of a given pixel to…

Instrumentation and Methods for Astrophysics · Physics 2015-02-18 A. Guyonnet , P. Astier , P. Antilogus , N. Regnault , P. Doherty

The weak distortions produced by gravitational lensing in the images of background galaxies provide a method to measure directly the distribution of mass in the universe. However this technique requires high precision measurements of the…

Astrophysics · Physics 2009-10-31 Jason Rhodes , Alexandre Refregier , Ed Groth

Weak gravitational lensing studies aim to measure small distortions in the shapes of distant galaxies, and thus place very tight demands on the understanding of detector-induced systematic effects in astronomical images. The Wide-Field…

Instrumentation and Methods for Astrophysics · Physics 2020-01-27 Christopher M. Hirata , Ami Choi

Background: Recently, the popularity of dual-layer flat-panel detector (DL-FPD) based dual-energy cone-beam CT (DE-CBCT) imaging has been increasing. However, the image quality of DE-CBCT remains constrained by the Compton scattered X-ray…

We describe a camera beam simulator for the LSST which is capable of illuminating a 60mm field at f/1.2 with realistic astronomical scenes, enabling studies of CCD astrometric and photometric performance. The goal is to fully simulate LSST…

Instrumentation and Methods for Astrophysics · Physics 2014-11-21 J. A. Tyson , J. Sasian , K. Gilmore , A. Bradshaw , C. Claver , M. Klint , G. Muller , G. Poczulp , E. Resseguie

Context. For accurately measuring intensities and determining magnetic field strengths of small-scale solar (magnetic) structure, knowledge of and compensation for the point spread function is crucial. For images recorded with the Swedish…

Instrumentation and Methods for Astrophysics · Physics 2015-05-19 G. B. Scharmer , M. G. Löfdahl , T. I. M. van Werkhoven , J. de la Cruz Rodriguez

The weak-lensing science of the LSST project drives the need to carefully model and separate the instrumental artifacts from the intrinsic lensing signal. The dominant source of the systematics for all ground based telescopes is the spatial…

Instrumentation and Methods for Astrophysics · Physics 2015-05-20 M. James Jee , J. Anthony Tyson

Accurate calibration of internal parameters is a crucial yet challenging prerequisite for 3D reconstruction using light field cameras. In this paper, we propose a linear fractional transformation(LFT) parameter $\alpha$ to decoupled the…

Computer Vision and Pattern Recognition · Computer Science 2025-11-07 Zhong Chen , Changfeng Chen

Extended source effects can be seen in gravitational lensing events when sources cross critical lines. Those events probe the stellar intensity profile and could be used to measure limb darkening coefficients to test stellar model…

Instrumentation and Methods for Astrophysics · Physics 2019-08-14 Hans J. Witt , F. Atrio-Barandela

The presence of fringing in astronomical CCD images will impact photometric quality and measurements. Yet its impact on the Vera C. Rubin Observatory's Legacy Survey of Space and Time (LSST) has not been fully studied. We present a detailed…

Instrumentation and Methods for Astrophysics · Physics 2023-03-28 Zhiyuan Guo , Chris W. Walter , Craig Lage , Robert H. Lupton , The LSST Dark Energy Science Collaboration

Automatic detection of faults in optical fibers is an active area of research that plays a significant role in the design of reliable and stable optical networks. A fiber measurement system that combines automated data acquisition and…

Signal Processing · Electrical Eng. & Systems 2021-11-05 Yuneisy Garcia Guzman , Felipe Calliari , Gustavo C. Amaral , Michael Lunglmayr
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