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The ultimate goal of the "Pi of the Sky" apparatus is observation of optical flashes of astronomical origin and other light sources variable on short timescales. We search mainly for optical emission of Gamma Ray Bursts, but also for…

Instrumentation and Methods for Astrophysics · Physics 2011-11-02 Lech Wiktor Piotrowski

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

Electric response of an x-ray mirror enclosed in a gas flow ionization chamber was studied under the conditions of total external reflection for hard x-rays. It is shown that the electric response of the system as a function of the…

Instrumentation and Detectors · Physics 2016-02-17 Stanislav Stoupin

Scattering of optical waves by a multi-scale rough mirror surface as a phase screen is considered. To solve the problem we used the diffusion phase approximation and numerical model of a phase jump. The scattering intensity was averaged…

Optics · Physics 2018-12-27 P. A. Golovinsky , D. K. Proskurin

Telescope Point Spread Function (PSF) quality is critical for realising the potential of cosmic weak lensing observations to constrain dark energy and test General Relativity. In this paper we use quantitative weak gravitational lensing…

Astronomical X-ray observatories with grazing incidence optics face the problem of pseudo-focusing of low energy protons from the mirrors towards the focal plane. Those protons constitute a variable, unpredictable component of the non X-ray…

Instrumentation and Methods for Astrophysics · Physics 2020-04-15 R. Amato , T. Mineo , A. D'Aì , S. Diebold , V. Fioretti , A. Guzman , S. Lotti , C. Macculi , S. Molendi , E. Perinati , C. Tenzer , A. Santangelo

We propose a compact snapshot monocular depth estimation technique that relies on an engineered point spread function (PSF). Traditional approaches used in microscopic super-resolution imaging such as the Double-Helix PSF (DHPSF) are…

Image and Video Processing · Electrical Eng. & Systems 2022-08-05 Bhargav Ghanekar , Vishwanath Saragadam , Dushyant Mehra , Anna-Karin Gustavsson , Aswin Sankaranarayanan , Ashok Veeraraghavan

The European XFEL is equipped with scintillating screens as a profile measurement monitor. The scintillating material used is Gadolinium Aluminium Gallium Garnet doped with Cerium (GAGG:Ce). At most of the stations, the screen is positioned…

Instrumentation and Detectors · Physics 2024-12-10 A. Novokshonov

The influence of low-spatial frequency errors of an optical component of an imaging system on the point spread function can be quantified using Zernike polynomials. High-spatial frequency errors cause strong scattering due to which the…

Optics · Physics 2026-04-03 Luuk Zonneveld , Paul Urbach , Aurèle Adam

The absolute reflectance of a reflector and its point spread function are the key parameters of a telescope for measuring light flux. Typically, one is using low-cost technologies for producing mirrors for the needs of astro-particle…

Instrumentation and Methods for Astrophysics · Physics 2018-10-22 Razmik Mirzoyan , Cornelia Arcaro , Hanna Kellermann , Markus Garczarczyik

We present results of inflight calibration of the point spread function (PSF) of the Soft X-ray Telescope (SXT-S) that focuses X-ray onto the pixel array of the Soft X-ray Spectrometer system (SXS). We make a full array image of a…

A new method for investigation of x-ray propagation in a rough narrow dielectric waveguide is proposed on the basis of the numerical integration of the quazioptical equation. In calculations a model rough surface was used with the given…

Optics · Physics 2007-05-23 T. A. Bobrova , L. I. Ognev

This paper introduces a new conceptual framework that recasts surface roughness effects as a "ray deflection function" (RDF) which can be statistically represented through a modified Zernike-Fourier hybrid approach that directly connects…

Optics · Physics 2025-08-12 Netzer Moriya

The accuracy in the photometry of a point source depends on the point-spread function (PSF), detector pixelization, and observing strategy. The PSF and pixel response describe the spatial blurring of the source, the pixel scale describes…

Instrumentation and Methods for Astrophysics · Physics 2012-02-02 Johan Samsing , Alex G. Kim

Accurate knowledge of the telescope's point spread function (PSF) is essential for the weak gravitational lensing measurements that hold great promise for cosmological constraints. For space telescopes, the PSF may vary with time due to…

Astrophysics · Physics 2009-11-13 Zhaoming Ma , Gary Bernstein , Alan Weinstein , Michael Sholl

Recently introduced angular-memory-effect based techniques enable non-invasive imaging of objects hidden behind thin scattering layers. However, both the speckle-correlation and the bispectrum analysis are based on the statistical average…

Optics · Physics 2017-11-22 Tengfei Wu , Jonathan Dong , Xiaopeng Shao , Sylvain Gigan

The goal of this effort is to establish the conditions and limits under which the Huygens-Fresnel principle accurately describes diffraction in the Monte Carlo ray-trace environment. This goal is achieved by systematic intercomparison of…

Optics · Physics 2018-05-23 J. R. Mahan , N. Q. Vinh , V. X. Ho , N. B. Munir

We propose a wavefront-based method to estimate the PSF over the whole field of view. This method estimate the aberrations of all the mirrors of the telescope using only field stars. In this proof of concept paper, we described the method…

Instrumentation and Methods for Astrophysics · Physics 2016-08-08 Ferréol Soulez , Frédéric Courbin , Michael Unser

Structure determination is a key application of XFELs and 4th generation synchrotron sources, particularly using the coherent and pulsed X-ray radiation from X-ray free-electron lasers (XFEL). Scientific interest focuses on understanding…

Instrumentation and Detectors · Physics 2025-03-07 Markus Kuster , Robert Hartmann , Steffen Hauf , Peter Holl , Tonn Rüter , Lothar Strüder

A spectrograph is an optical instrument that disperses photons of different energies into distinct directions and space locations, and images photon spectra on a position-sensitive detector. Spectrographs consist of collimating, angular…

Optics · Physics 2015-06-11 Yuri Shvyd'ko