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Related papers: Phasing a deployable sparse telescope

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We describe the optimum telescope focal ratio for a two-element, three surface, telecentric image-transfer microlens-to-fiber coupled integral field unit within the constraints imposed by micro-optics fabrication and optical aberrations. We…

Instrumentation and Methods for Astrophysics · Physics 2022-05-09 Sabyasachi Chattopadhyay , Matthew A. Bershady , Marsha J. Wolf , Michael P. Smith

A perfect focus telescope is one in which all rays parallel to the axis meet at a point and give equal magnification there. It is shown that these two conditions define the shapes of both primary and secondary mirrors. Apart from scale, the…

Optics · Physics 2009-11-07 D. Lynden-Bell

Equipped with a suitable optical relay system, telescopes employing low-cost fixed primary mirrors could point and track while delivering high-quality images to a fixed location. Such an optical tracking system would enable liquid-mirror…

Astrophysics · Physics 2009-11-06 Paul Hickson

Sparse decomposition has been widely used for different applications, such as source separation, image classification, image denoising and more. This paper presents a new algorithm for segmentation of an image into background and foreground…

Computer Vision and Pattern Recognition · Computer Science 2016-07-28 Shervin Minaee , Yao Wang

This paper describes a fast and accurate method for obtaining steerable principal components from a large dataset of images, assuming the images are well localized in space and frequency. The obtained steerable principal components are…

Computer Vision and Pattern Recognition · Computer Science 2018-08-10 Boris Landa , Yoel Shkolnisky

Microscope objectives achieve near diffraction-limited performance only when used under the conditions they are designed for. In non-standard geometries, such as thick cover slips or curved surfaces, severe aberrations arise, inevitably…

Optics · Physics 2025-03-24 D. W. S. Cox , T. Knop , I. M. Vellekoop

Recent advancements in low-cost astronomical equipment, including high-quality medium-aperture telescopes and low-noise CMOS detectors, have made the deployment of large optical telescope arrays both financially feasible and scientifically…

Instrumentation and Methods for Astrophysics · Physics 2022-08-19 Nathan W. Galliher , Nicholas M. Law , Hank Corbett , Ramses Gonzalez , Lawrence Machia , Alan Vasquez Soto

Modern extreme adaptive optics (AO) systems achieving diffraction-limited performance open up new possibilities for instrumentation. Especially important for the fields of spectroscopy and interferometry is that it enables the prospect to…

We outline here a simple yet efficient method for finding optimized configurations of the elements of radio-astronomical interferometers with fixed pad locations. The method can be successfully applied, as we demonstrate, to define new…

Astrophysics · Physics 2009-11-11 A. Karastergiou , R. Neri , M. A. Gurwell

Continuous wavefront sensing benefits space observatories in on-orbit optical performance maintenance. To measure the phase of a wavefront, phase retrieval is an attractive technique as it uses multiple point spread function (PSF) images…

Instrumentation and Methods for Astrophysics · Physics 2024-09-17 Hyukmo Kang , Kyle Van Gorkom , Meghdoot Biswas , Daewook Kim , Ewan S. Douglas

Accurate reconstruction of the spatial distributions of the Point Spread Function (PSF) is crucial for high precision cosmic shear measurements. Nevertheless, current methods are not good at recovering the PSF fluctuations of high spatial…

Cosmology and Nongalactic Astrophysics · Physics 2021-07-12 Tianhuan Lu , Jun Zhang , Fuyu Dong , Yingke Li , Dezi Liu , Liping Fu , Guoliang Li , Zuhui Fan

An image super-resolution method from multiple observation of low-resolution images is proposed. The method is based on sub-pixel accuracy block matching for estimating relative displacements of observed images, and sparse signal…

Computer Vision and Pattern Recognition · Computer Science 2014-02-18 Toshiyuki Kato , Hideitsu Hino , Noboru Murata

Image convolution with complex kernels is a fundamental operation in photography, scientific imaging, and animation effects, yet direct dense convolution is computationally prohibitive on resource-limited devices. Existing approximations,…

Graphics · Computer Science 2026-05-20 Zhizhen Wu , Zhe Cao , Yuchi Huo

Spectral cameras with integrated thin-film Fabry-P\'erot filters have become increasingly important in many applications. These applications often require the detection of spectral features at specific wavelengths or to quantify small…

Optics · Physics 2019-05-16 Thomas Goossens , Bert Geelen , Andy Lambrechts , Chris Van Hoof

We present a new technique - photon folding - for imaging in non-focusing telescopes. Motivated by the epoch-folding method in timing analysis, the photon folding technique directly provides the statistical significance of signals in…

Astrophysics · Physics 2009-11-07 JaeSub Hong

We have designed and constructed a ``dispersed Fourier Transform Spectrometer'' (dFTS), consisting of a conventional FTS followed by a grating spectrometer. By combining these two devices, we negate a substantial fraction of the sensitivity…

In recent years, a great deal of emphasis has been placed on achieving the diffraction limit with large aperture telescopes. For a well matched focal-plane instrument, the diffraction limit provides the highest possible angular resolution…

Astrophysics · Physics 2009-11-11 J. Bland-Hawthorn , A. Horton

In this Chapter we review the challenges of, and opportunities for, 3D spectroscopy, and how these have lead to new and different approaches to sampling astronomical information. We describe and categorize existing instruments on 4m and 10m…

Instrumentation and Methods for Astrophysics · Physics 2009-10-02 Matthew A. Bershady

Optimal error estimation is key to achieve accurate photometry and astrometry. Stellar fluxes and positions in high angular resolution images are typically measured with PSF fitting routines, such as StarFinder. However, the formal…

Instrumentation and Methods for Astrophysics · Physics 2022-08-12 E. Gallego-Cano , R. Schödel , A. T. Gallego-Calvente , A. M. Ghez

When a disordered array of coupled waveguides is illuminated with an extended coherent optical field, discrete speckle develops: partially coherent light with a granular intensity distribution on the lattice sites. The same paradigm applies…

Optics · Physics 2017-07-11 H. Esat Kondakci , Ayman F. Abouraddy , Bahaa E. A. Saleh