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In this letter, a fast Fourier transform (FFT)-enhanced low-complexity super-resolution sensing algorithm for near-field source localization with both angle and range estimation is proposed. Most traditional near-field source localization…

Signal Processing · Electrical Eng. & Systems 2024-11-26 Yuxiao Wu , Huizhi Wang , Yong Zeng

Large Array of imaging atmospheric Cherenkov Telescope (LACT) is an array of 32 Cherenkov telescopes with 6-meter diameter mirrors to be constructed at the LHAASO site, aiming to enhance our understanding of ultra-high energy gamma ray…

High Energy Astrophysical Phenomena · Physics 2025-09-26 Zhipeng Zhang , Ruizhi Yang , Shoushan Zhang

The Imaging Atmospheric Cherenkov technique allows to detect very high energy gamma rays from few tens of GeV to hundreds of TeV using ground-based instrumentation. At these energies a gamma ray generates a shower of secondary particles…

Instrumentation and Methods for Astrophysics · Physics 2023-06-13 Juan Cortina , Carlos Delgado

For air showers observed simultaneously by more than two imaging atmospheric Cherenkov telescopes, the shower geometry is overconstrained by the images and image information should be combined taking into account the quality of the images.…

Astrophysics · Physics 2011-05-23 W. Hofmann , I. Jung , A. Konopelko , H. Krawczynski , H. Lampeitl , G. Puehlhofer

A Discrete Fourier Transform Method (DFTM) for discrimination between the signal of neutrons and gamma rays in organic scintillation detectors is presented. The method is based on the transformation of signals into the frequency domain…

Instrumentation and Detectors · Physics 2016-11-03 M. J. Safari , F. Abbasi Davani , H. Afarideh , S. Jamili , E. Bayat

To date, endovascular surgeries are performed using the golden standard of Fluoroscopy, which uses ionising radiation to visualise catheters and vasculature. Prolonged Fluoroscopic exposure is harmful for the patient and the clinician, and…

Image and Video Processing · Electrical Eng. & Systems 2023-09-27 Alex Ranne , Yordanka Velikova , Nassir Navab , Ferdinando Rodriguez y Baena

A versatile method is described for the practical computation of the discrete Fourier transforms (DFT) of a continuous function $g(t)$ given by its values $g_{j}$ at the points of a uniform grid $F_{N}$ generated by conjugacy classes of…

Mathematical Physics · Physics 2009-11-10 A. Atoyan , J. Patera

GAW (Gamma Air Watch) is a pathfinder experiment in the TeV range to test the feasibility of a new generation of Imaging Atmospheric Cherenkov Telescopes (IACT). It combines high flux sensitivity with large field-of-view (FoV=24deg x 24deg)…

High Energy Astrophysical Phenomena · Physics 2010-06-14 Luisa Arruda , GAW collaboration

We present a general theory of fractal transformations and show how it leads to a new type of method for filtering and transforming digital images. This work substantially generalizes earlier work on fractal tops. The approach involves…

Geometric Topology · Mathematics 2011-02-17 Michael F. Barnsley , Brendan Harding , Konstantin Igudesman

Imaging atmospheric Cherenkov telescopes (IACTs) used for ground-based gamma-ray astronomy at TeV energies use reflectors with areas on the order of 100m$^2$ as their primary optic. These tessellated reflectors comprise hundreds of mirror…

Instrumentation and Methods for Astrophysics · Physics 2014-11-20 A. McCann , D. Hanna , J. Kildea , M. McCutcheon

In this paper we explain how to use the Fast Fourier Transform (FFT) to solve partial differential equations (PDEs). We start by defining appropriate discrete domains in coordinate and frequency domains. Then describe the main limitation of…

Numerical Analysis · Mathematics 2025-07-31 Daniela Rodriguez-Lara , Ivan Alvarez-Rios , Francisco S. Guzman

Identification of Cherenkov light generated by muons has been suggested as a promising way to dramatically improve the background rejection power of Imaging Atmospheric Cherenkov Telescope (IACT) arrays at high energies. However, muon…

High Energy Astrophysical Phenomena · Physics 2022-12-13 Laura Olivera-Nieto , Helena X. Ren , Alison M. W. Mitchell , Vincent Marandon , Jim Hinton

In this paper, we present an assortment of both standard and advanced Fourier techniques that are useful in the analysis of astrophysical time series of very long duration -- where the observation time is much greater than the time…

Astrophysics · Physics 2009-11-07 Scott M. Ransom , Stephen S. Eikenberry , John Middleditch

Fourier-transform infrared spectroscopy (FTIR) is a powerful analytical method for not only the chemical identification of solid, liquid, and gas species, but also the quantification of their concentration. However, the chemical…

In recent years, ground-based very-high-energy (VHE; E>100 GeV) gamma-ray astronomy has experienced a major breakthrough with the impressive astrophysical results obtained mainly by the current generation experiments like H.E.S.S., MAGIC,…

Instrumentation and Methods for Astrophysics · Physics 2019-08-14 R. M. Wagner , E. J. Lindfors , A. Sillanpää , S. Wagner

Imaging atmospheric Cherenkov telescopes (IACTs) are the main technique for detecting gamma rays with energies between tens of GeV and hundreds of TeV. Amongst them, the High Energy Stereoscopic System (H.E.S.S.) has pioneered the use of…

High Energy Astrophysical Phenomena · Physics 2026-04-01 Rodrigo Guedes Lang , Tim Unbehaun , Lars Mohrmann , Simon Steinmassl , Jim Hinton , Stefan Funk

Non-line-of-Sight (NLOS) imaging systems collect light at a diffuse relay surface and input this measurement into computational algorithms that output a 3D volumetric reconstruction. These algorithms utilize the Fast Fourier Transform (FFT)…

Image and Video Processing · Electrical Eng. & Systems 2025-01-14 Talha Sultan , Alex Bocchieri , Chaoying Gu , Xiaochun Liu , Pavel Polynkin , Andreas Velten

Reconstruction of energies of very-high-energy gamma-rays observed by imaging atmospheric Cherenkov telescopes is affected by changes in the atmospheric conditions and the performance of telescope components. Reliable calibration schemes…

Instrumentation and Methods for Astrophysics · Physics 2019-09-24 Stanislav Stefanik , Dalibor Nosek

The recent demonstration of a real-time direct imaging radio interferometry correlator represents a new capability in radio astronomy. However wide field imaging with this method is challenging since wide-field effects and array…

Instrumentation and Methods for Astrophysics · Physics 2020-01-08 James Kent , Adam P. Beardsley , Landman Bester , Steve F. Gull , Bojan Nikolic , Jayce Dowell , Nithyanandan Thyagarajan , Greg B. Taylor , Judd Bowman

The simulation of atmospheric showers through Monte-Carlo processes as well as their projection into Imaging Atmospheric Cherenkov Telescopes (IACT) is long and very computing intensive. As these simulations are the most advanced ones from…

Instrumentation and Methods for Astrophysics · Physics 2017-09-15 Thomas Vuillaume , Florian Gaté , Gilles Maurin , Jean Jacquemier , Giovanni Lamanna