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We report in this paper the test of a plane holographic optical element to be used as an aberration-corrected grating for a slitless spectrograph, inserted in a convergent telescope beam. Our long term objective is the optimisation of a…

Instrumentation and Methods for Astrophysics · Physics 2021-08-18 Marc Moniez , Jérémy Neveu , Sylvie Dagoret-Campagne , Yves Gentet , Laurent Le Guillou

We report a novelly universal scheme for design of a grazing incidence spectrometer, which creates an excellent meridional flat field in its detector domain to deliver the desired spectral resolution throughout the full designated spectral…

Optics · Physics 2017-10-13 Zhuo Li , Bin Li

The aim of this paper is to present an analytical relationship between the power spectral density of GRACE-like mission measurements and the accuracies of the gravity field coefficients mainly from the point of view of theory of signal and…

Geophysics · Physics 2016-09-29 Lin Cai , Zebing Zhou , Qiong Li , Zhicai Luo , Houtse Hsu

Background: To ensure consistent and high-quality semiconductor production at future logic nodes, additional metrology tools are needed. For this purpose, grazing-incidence small-angle X-ray scattering (GISAXS) is being considered because…

Unlike a traditional gyroscope, a visual gyroscope estimates camera rotation through images. The integration of omnidirectional cameras, offering a larger field of view compared to traditional RGB cameras, has proven to yield more accurate…

Computer Vision and Pattern Recognition · Computer Science 2024-09-24 Yao Du , Carlos M. Mateo , Mirjana Maras , Tsun-Hsuan Wang , Marc Blanchon , Alexander Amini , Daniela Rus , Omar Tahri

We develop a method to estimate the power spectrum of a stochastic process on the sphere from data of limited geographical coverage. Our approach can be interpreted either as estimating the global power spectrum of a stationary process when…

Instrumentation and Methods for Astrophysics · Physics 2013-06-17 Mark A. Wieczorek , Frederik J. Simons

Massively multiplexed spectrographs will soon gather large statistical samples of stellar spectra. The accurate estimation of uncertainties on derived parameters, such as line-of-sight velocity $v_\mathrm{los}$, especially for spectra with…

Instrumentation and Methods for Astrophysics · Physics 2024-07-23 László Dobos , Alexander S. Szalay , Tamás Budavári , Evan N. Kirby , Robert H. Lupton , Rosemary F. G. Wyse

Computational spectrometers are pivotal in enabling low-cost, in-situ and rapid spectral analysis, with potential applications in chemistry, biology, and environmental science. However, filter-based spectral encoding approaches typically…

Spectral graph sparsification aims to find ultra-sparse subgraphs which can preserve spectral properties of original graphs. In this paper, a new spectral criticality metric based on trace reduction is first introduced for identifying…

Data Structures and Algorithms · Computer Science 2022-06-14 Zhiqiang Liu , Wenjian Yu

A major challenge in Atomic Force Microscopy (AFM) is to reduce the scan duration while retaining the image quality. Conventionally, the scan rate is restricted to a sufficiently small value in order to ensure a desirable image quality as…

Signal Processing · Electrical Eng. & Systems 2019-02-13 Kaixiang Wang , Michael G. Ruppert , Chris Manzie , Dragan Nesic , Yuen K. Yong

Subsampling is a widely used and effective approach for addressing the computational challenges posed by massive datasets. Substantial progress has been made in developing non-uniform, probability-based subsampling schemes that prioritize…

Methodology · Statistics 2026-05-07 Dingyi Wang , Haiying Wang , Qingpei Hu

Scanning Electron Microscopy (SEM) images often suffer from noise contamination, which degrades image quality and affects further analysis. This research presents a complete approach to estimate their Signal-to-Noise Ratio (SNR) and noise…

Machine Learning · Computer Science 2025-10-10 D. Chee Yong Ong , I. Bukhori , K. S. Sim , K. Beng Gan

The 44-cm Visible Telescope (VT) aboard the Space-based Variable Objects Monitor (SVOM) is a dual-band (400-650 nm and 650-1000 nm) instrument designed to detect and characterize the optical counterparts of gamma-ray bursts (GRBs) and other…

We examine SDO/EVE data to better understand solar flare irradiance, and how that irradiance may vary for large events. We measure scaling laws relating GOES flare classes to irradiance in 21 lines measured with SDO/EVE, formed across a…

Solar and Stellar Astrophysics · Physics 2022-03-14 Jeffrey W. Reep , David E. Siskind , Harry P. Warren

The Fast Fourier Transform (FFT) is widely used in applications such as MRI, CT, and interferometry; however, because of its dependence on uniformly sampled data, it requires the use of gridding techniques for practical implementation. The…

Numerical Analysis · Mathematics 2025-12-22 Federico Achini , Paola Causin , Sara Vanini , Ke Chen , Simone Scacchi

Multifocal microscopy (MFM) offers high-speed three-dimensional imaging through the simultaneous image capture from multiple focal planes. Conventional MFM systems use a fabricated grating in the emission path for a single emission…

Biological Physics · Physics 2019-07-31 M. Junaid Amin , Sabine Petry , Haw Yang , Joshua W. Shaevitz

In this paper, we simulate a front surface inverted pyramidal grating texture on 2 to 400 micron thick silicon and optimize it to derive maximum photocurrent density from the cell. We identify a one size fits all front grating period of…

Optics · Physics 2016-06-07 K Kumar , A Khalatpour , G Liu , J Nogami , N P Kherani

Optical intelligent reflecting surface (OIRS) has been considered a promising technology for visible light communication (VLC) by constructing visual line-of-sight propagation paths to address the signal blockage issue. However, the…

Information Theory · Computer Science 2024-04-24 Shiyuan Sun , Fang Yang , Weidong Mei , Jian Song , Zhu Han , Rui Zhang

Traditional glass-based optics are typically optimized for narrow spectral bands, such as the visible (400-700nm) or shortwave infrared (1000-1800nm). While the emergence of VIS-SWIR sensors (400-1700nm) offers transformative potential,…

Image and Video Processing · Electrical Eng. & Systems 2026-05-04 Vishwanath Saragadam , Niki Nezakati , Amit Roy-Chowdhury , Vivek Boominathan

Diffraction gratings with large angular dispersion rates are central to obtaining high spectral resolution in grating spectrometers operating over a broad spectral range from infrared to soft-x-ray domains. The greatest challenge is of…

Optics · Physics 2021-05-18 Yuri Shvyd'ko
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