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Related papers: A Fourier method for the determination of focus fo…

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We propose a form of a lens corrector at the prime focus of a hyperboloidal mirror that provides a flat field of view up to 3 deg diameter at image quality D_{80} < 0.8 arcsec in integrated (0.32-1.10 mcm) light. The corrector consists of…

Astrophysics · Physics 2014-10-13 V. Yu. Terebizh

The focusing of atoms interacting with both far-detuned and resonant standing wave fields in the thin lens regime is considered. The thin lens approximation is discussed quantitatively from a quantum perspective. Exact quantum expressions…

Atomic Physics · Physics 2009-10-31 J. L. Cohen , B. Dubetsky , P. R. Berman

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

We propose the segmented Large Millimeter Telescope (LMT/GTM),as the largest spatial light modulator capable of producing vortex beams of integer topological charge. This observing mode could be applied for direct exoplanet searches in the…

Instrumentation and Methods for Astrophysics · Physics 2017-08-23 Juan P. Treviño , Omar López-Cruz , Sabino Chávez-Cerda

We present studies for optimizing the next generation of ground-based imaging atmospheric Cherenkov telescopes (IACTs). Results focus on mid-sized telescopes (MSTs) for CTA, detecting very high energy gamma rays in the energy range from a…

Instrumentation and Methods for Astrophysics · Physics 2015-07-15 M. Wood , T. Jogler , J. Dumm , S. Funk

This paper is concerned with a direct sampling method for imaging the support of a frequency-dependent source term embedded in a homogeneous and isotropic medium. The source term is given by the Fourier transform of a time-dependent source…

Numerical Analysis · Mathematics 2022-12-12 Hongxia Guo , Guanghui Hu , Mengjie Zhao

The NectarCAM flat-field flasher is a calibration device designed for the camera that will equip the Medium-Sized Telescopes (MSTs) of the northern site of the Cherenkov Telescope Array Observatory (CTAO). Positioned in the centre of the…

Fourier ptychographi cmicroscopy(FPM) is a newly developed computational imaging technique that can provide gigapixel images with both high resolution (HR) and wide field of view (FOV). However, the positional misalignment of the LED array…

Computer Vision and Pattern Recognition · Computer Science 2018-09-03 Ao Zhou , Wei Wang , Ni Chen , Edmund Y. Lam , Byoungho Lee , Guohai Situ

The First G-APD Cherenkov telescope (FACT) is the first telescope using silicon photon detectors (G-APD aka. SiPM). The use of Silicon devices promise a higher photon detection efficiency, more robustness and higher precision than…

In order to understand the appropriate field of view (FOV) size of celestial automatic navigation systems for surface ships, we investigate the variations of measurement accuracy of star position and probability of successful star…

A point spread function (PSF) describes the distribution of light for a pure point source in an astronomical image due to the optics of the instrument. An accurate PSF is key for deconvolution, point source photometry and source removal.…

Instrumentation and Methods for Astrophysics · Physics 2025-07-28 Ava Polzin

Image resolvability is the primary concern in imaging. This paper reports an estimation of the full width at half maximum of the point spread function from a Fourier domain plot of real sample images by neither using test objects, nor…

High-precision radial velocity (RV) measurements are crucial for exoplanet detection and characterisation. Efforts to achieve ~10 cm/s precision have been made over the recent decades, with significant advancements in instrumentation, data…

Instrumentation and Methods for Astrophysics · Physics 2023-09-11 Sahar Shahaf , Barak Zackay

Here we report nonlinear focal modulation microscopy (NFOMM) to achieve super-resolution imaging. Abandoning the previous persistence on minimizing the size of Gaussian emission pattern by directly narrowing (e.g. Minimizing the detection…

We present the results of a study along with a first prototype of a high precision system (? 1 arcsec) for pointing and tracking light (near-infrared) telescopes on board stratospheric balloons. Such a system is essentially composed by a…

Instrumentation and Methods for Astrophysics · Physics 2011-04-13 M. Ricci , F. Pedichini , D. Lorenzetti

Large-format (sub)millimeter wavelength imaging arrays are best operated in scanning observing modes rather than traditional position-switched (chopped) modes. The choice of observing mode is critical for isolating source signals from…

Astrophysics · Physics 2014-11-18 A. Kovacs

The power of asteroseismology relies on the ability to infer the stellar structure from the unambiguous frequency identification of the corresponding pulsation mode. Hence, the use of a Fourier transform is in the basis of asteroseismic…

Solar and Stellar Astrophysics · Physics 2015-07-29 J. Pascual-Granado , R. Garrido , J. C. Suárez

We present a technique based on multi-photon detection which leads to a strong focussing of photons scattered by independent single photon emitters. For N single photon sources it is shown that if m - 1 photons are detected in a particular…

Quantum Physics · Physics 2012-02-02 R. Wiegner , S. Oppel , J. von Zanthier , G. S. Agarwal

We have developed a new three-dimensional algorithm, based on the standard P$^3$M method, for computing deflections due to weak gravitational lensing. We compare the results of this method with those of the two-dimensional planar approach,…

Astrophysics · Physics 2009-10-31 H. M. P. Couchman , Andrew J. Barber , Peter A. Thomas

A new method of quantum state tomography for quantum information processing is described. The method based on two-dimensional Fourier transform technique involves detection of all the off-diagonal elements of the density matrix in a…

Quantum Physics · Physics 2009-11-07 Ranabir Das , T. S. Mahesh , Anil Kumar