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High-resolution imaging of ultracold atoms typically requires custom high numerical aperture (NA) optics, as is the case for quantum gas microscopy. These high NA objectives involve many optical elements each of which contributes to loss…

Quantum Gases · Physics 2021-11-01 Emine Altuntas , Ian B. Spielman

The increased sensitivity of future radio telescopes will result in requirements for higher dynamic range within the image as well as better resolution and immunity to interference. In this paper we propose a new matrix formulation of the…

Astrophysics · Physics 2014-11-18 Chen Ben-David , Amir Leshem

In many mechanical, electrical, and general physical systems evolving over time or space, spectral analysis methods as Fast Fourier Transform (FFT), Short Term Fourier Transform (STFT), Power Spectrum Density (PSD) plays a very important…

Signal Processing · Electrical Eng. & Systems 2023-06-21 Andreas Tuor , Nico Canzani , Tobias Rüggeberg , Stefan Gorenflo , Gerd Simons , Bruno Bättig , Daniel Iseli

We present a simple, effective approach for estimating the on-order backgrounds of spectra taken with the highest-resolution modes of the Space Telescope Imaging Spectrograph (STIS) on-board the Hubble Space Telescope. Our scheme for…

Astrophysics · Physics 2009-10-31 J. Christopher Howk , Kenneth R. Sembach

For diffraction-limited optical systems an accurate physical optics model is necessary to properly evaluate instrument performance. Astronomical observatories outfitted with coronagraphs for direct exoplanet imaging require physical optics…

Instrumentation and Methods for Astrophysics · Physics 2023-11-01 Jaren N. Ashcraft , Ewan S. Douglas , Daewook Kim , A. J. E. Riggs

This paper presents a framework for developing a live vision-correcting display (VCD) to address refractive visual aberrations without the need for traditional vision correction devices like glasses or contact lenses, particularly in…

Image and Video Processing · Electrical Eng. & Systems 2025-01-06 Akhilesh Balaji , Dhruv Ramu

Wide field interferometry has become a subject of increasing interest in the recent years. New methods have been suggested in order to avoid the drawbacks of the standard wide-field method (homothetic mapping) which is not applicable when…

Astrophysics · Physics 2007-05-23 I. Montilla , J. Sellos , S. F. Pereira , J. J. M. Braat

Purpose: To reconstruct artifact-free images from measured k-space data, when the actual k-space trajectory deviates from the nominal trajectory due to gradient imperfections. Methods: Trajectory errors arising from eddy currents and…

Medical Physics · Physics 2018-02-13 Merry Mani , Vincent Magnotta , Mathews Jacob

Waveform decomposition is needed as a first step in the extraction of various types of geometric and spectral information from hyperspectral full-waveform LiDAR echoes. We present a new approach to deal with the "Pseudo-monopulse" waveform…

Signal Processing · Electrical Eng. & Systems 2023-06-12 Yuhao Xia , Shilong Xu , Hui Shao , Ahui Hou , Jiajie Fang , Fei Han , Youlong Chen , Jiaqi Wen , Yuwei Chen , Yihua Hu

Hyperspectral imaging is a cutting-edge type of remote sensing used for mapping vegetation properties, rock minerals and other materials. A major drawback of hyperspectral imaging devices is their intrinsic low spatial resolution. In this…

Computer Vision and Pattern Recognition · Computer Science 2022-08-16 Leon Bungert , David A. Coomes , Matthias J. Ehrhardt , Jennifer Rasch , Rafael Reisenhofer , Carola-Bibiane Schönlieb

Linear-array based photoacoustic images are reconstructed using the conventional delay-and-sum (DAS) beamforming method. Although the DAS beamformer is well suited for PA image formation, reconstructed images are often afflicted by noises,…

Medical Physics · Physics 2022-10-05 Sufayan Mulani , Souradip Paul , Mayanglambam Suheshkumar Singh

The study of astronomical phenomena through ground-based observations is always challenged by the distorting effects of Earth's atmosphere. Traditional methods of post-facto image correction, essential for correcting these distortions,…

Instrumentation and Methods for Astrophysics · Physics 2024-08-14 A. Asensio Ramos

Image blur and image noise are imaging artifacts intrinsically arising in image acquisition. In this paper, we consider multi-frame blind deconvolution (MFBD), where image blur is described by the convolution of an unobservable,…

Computer Vision and Pattern Recognition · Computer Science 2022-10-04 Leonid Kostrykin , Stefan Harmeling

Exposure correction is one of the fundamental tasks in image processing and computational photography. While various methods have been proposed, they either fail to produce visually pleasing results, or only work well for limited types of…

Computer Vision and Pattern Recognition · Computer Science 2019-10-31 Qing Zhang , Yongwei Nie , Wei-Shi Zheng

Diffusion MRI is a well established imaging modality providing a powerful way to probe the structure of the white matter non-invasively. Despite its potential, the intrinsic long scan times of these sequences have hampered their use in…

Quantitative Methods · Quantitative Biology 2013-12-31 Alessandro Daducci , Dimitri Van De Ville , Jean-Philippe Thiran , Yves Wiaux

Context: Characterization of instrumental effects in astronomical imaging is important in order to extract accurate physical information from the observations. The measured image in a real optical instrument is usually represented by the…

Computer Vision and Pattern Recognition · Computer Science 2016-01-12 Adriana Gonzalez , Véronique Delouille , Laurent Jacques

Observations from ground based telescopes are affected by the presence of the Earth atmosphere, which severely perturbs them. The use of adaptive optics techniques has allowed us to partly beat this limitation. However, image selection or…

Instrumentation and Methods for Astrophysics · Physics 2021-02-17 A. Asensio Ramos , N. Olspert

High-order accurate summation-by-parts (SBP) finite difference (FD) methods constitute efficient numerical methods for simulating large-scale hyperbolic wave propagation problems. Traditional SBP FD operators that approximate first-order…

Numerical Analysis · Mathematics 2021-07-27 Kenneth Duru , Frederick Fung , Christopher Williams

The Swedish 1-m Solar Telescope (SST) offers excellent imaging quality, but it has a comparatively small field of view. This means that while observing the solar photosphere, there has been no convenient way of calibrating the image scale…

Instrumentation and Methods for Astrophysics · Physics 2013-11-21 Alexander Norén

In this paper, we present an original observational approach, which combines, for the first time, traditional speckle imaging with image post-processing to obtain in the optical domain diffraction-limited images with high contrast (1e-5)…

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