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Related papers: Correlation-based Beam Calibration of 21cm Intensi…

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Optical aberrations prevent telescopes from reaching their theoretical diffraction limit. Once estimated, these aberrations can be compensated for using deformable mirrors in a closed loop. Focal plane wavefront sensing enables the…

This paper investigates calibration of sensor arrays in the radio astronomy context. Current and future radio telescopes require computationally efficient algorithms to overcome the new technical challenges as large collecting area, wide…

Applications · Statistics 2018-07-31 Virginie Ollier , Mohammed Nabil El Korso , André Ferrari , Rémy Boyer , Pascal Larzabal

We present an investigation of the horizon and its effect on global 21-cm observations and analysis. We find that the horizon cannot be ignored when modeling low frequency observations. Even if the sky and antenna beam are known exactly,…

Cosmology and Nongalactic Astrophysics · Physics 2021-12-15 Neil Bassett , David Rapetti , Keith Tauscher , Bang D. Nhan , David D. Bordenave , Joshua J. Hibbard , Jack O. Burns

Correlation Filters (CFs) have recently demonstrated excellent performance in terms of rapidly tracking objects under challenging photometric and geometric variations. The strength of the approach comes from its ability to efficiently learn…

Computer Vision and Pattern Recognition · Computer Science 2017-03-23 Hamed Kiani Galoogahi , Ashton Fagg , Simon Lucey

The existing binary foreground map (FM) measures to address various types of errors in either pixel-wise or structural ways. These measures consider pixel-level match or image-level information independently, while cognitive vision studies…

Computer Vision and Pattern Recognition · Computer Science 2019-09-04 Deng-Ping Fan , Cheng Gong , Yang Cao , Bo Ren , Ming-Ming Cheng , Ali Borji

Raman spectroscopy has attracted interest as a non-invasive optical technique to study the composition and structure of a wide range of materials at the microscopic level. The intrinsic fluorescence background can be orders of magnitude…

Materials Science · Physics 2015-10-28 P. J. Cadusch , M. M. Hlaing , S. A. Wade , S. L. McArthur , P. R. Stoddart

Measurement of the global 21-cm signal during Cosmic Dawn (CD) and the Epoch of Reionization (EoR) is made difficult by bright foreground emission which is 2-5 orders of magnitude larger than the expected signal. Fitting for a…

Cosmology and Nongalactic Astrophysics · Physics 2024-02-20 Michael Pagano , Peter Sims , Adrian Liu , Dominic Anstey , Will Handley , Eloy De Lera Acedo

We propose to enhance the performance of localized plasmon structured illumination microscopy (LP-SIM) via intensity correlations. LP-SIM uses sub-wavelength illumination patterns to encode high spatial frequency information. It can enhance…

We report on a broader evaluation of statistical bootstrap resampling methods as a tool for pixel-level calibration and imaging fidelity assessment in radio interferometry. Pixel-level imaging fidelity assessment is a challenging problem,…

Instrumentation and Methods for Astrophysics · Physics 2015-05-14 Athol Kemball , Adam Martinsek , Modhurita Mitra , Hsin-Fang Chiang

Neutral hydrogen (HI) intensity mapping (IM) presents great promise for future cosmological large-scale structure surveys. However, a major challenge for HIIM cosmological studies is to accurately subtract the foreground contamination. An…

Instrumentation and Methods for Astrophysics · Physics 2025-04-10 Xinyang Zhao , Yichao Li , Wenxiu Yang , Furen Deng , Yougang Wang , Fengquan Wu , Xin Wang , Xiaohui Sun , Xin Zhang , Xuelei Chen

Many low-frequency radio interferometers are aiming to detect very faint spectral signatures from structures at cosmological redshifts, particularly of neutral Hydrogen using its characteristic 21 cm spectral line. Due to the very high…

Cosmology and Nongalactic Astrophysics · Physics 2020-07-03 Nithyanandan Thyagarajan , Chris Carilli

21-cm Intensity Mapping (IM) is a promising approach to detecting information about the large-scale structure beyond the local universe. One of the biggest challenges for an IM observation is the foreground removal procedure. In this paper,…

Signal Processing · Electrical Eng. & Systems 2025-06-10 Lin-Cheng Li , Jia-Yu Lin , Yuan-Gen Wang , Lister Staveley-Smith

The measurement of Doppler velocity shifts in spectra is a ubiquitous theme in astronomy, usually handled by computing the cross-correlation of the signals, and finding the location of its maximum. This paper addresses the problem of the…

Astrophysics · Physics 2008-11-26 Carlos Allende Prieto

High fidelity radio interferometric data calibration that minimises spurious spectral structure in the calibrated data is essential in astrophysical applications, such as 21 cm cosmology, which rely on knowledge of the relative spectral…

Instrumentation and Methods for Astrophysics · Physics 2022-10-26 Peter H. Sims , Jonathan C. Pober , Jonathan L. Sievers

Although Neural Radiance Fields (NeRFs) have markedly improved novel view synthesis, accurate uncertainty quantification in their image predictions remains an open problem. The prevailing methods for estimating uncertainty, including the…

Computer Vision and Pattern Recognition · Computer Science 2024-09-23 Niki Amini-Naieni , Tomas Jakab , Andrea Vedaldi , Ronald Clark

Accurately simulating the atmospheric turbulence behaviour is always challenging. The well-known FFT based method falls short in correctly predicting both the low and high frequency behaviours. Sub-harmonic compensation aids in…

Instrumentation and Methods for Astrophysics · Physics 2022-08-15 Sorabh Chhabra , Jyotirmay Paul , A. N. Ramaprakash , Avinash Surendran

Currently, there are no learning-free or neural techniques for real-time recalibration of infrared multi-camera systems. In this paper, we address the challenge of real-time, highly-accurate calibration of multi-camera infrared systems, a…

Computer Vision and Pattern Recognition · Computer Science 2024-10-21 Benyamin Mehmandar , Reza Talakoob , Charalambos Poullis

Intensity mapping of the HI 21 cm line and the CO 2.61 mm line from the epoch of reionization has emerged as powerful, complementary, probes of the high-redshift Universe. However, both maps and their cross-correlation are dominated by…

Cosmology and Nongalactic Astrophysics · Physics 2021-01-11 Meng Zhou , Jianrong Tan , Yi Mao

Quantum illumination uses quantum correlations to enhance the detection of an object in the presence of background noise. This advantage has been shown to exist even if one uses non-optimal direct measurements on the two correlated modes.…

Quantum Physics · Physics 2023-11-06 Thomas Brougham , Nigam Samantaray , John Jeffers

CPI is a novel imaging modality capable of addressing the intrinsic limitations of conventional plenoptic imaging - namely, the resolution loss and the sacrificed change of perspective, - while guaranteeing the typical advantages of…