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Related papers: 1/f Noise Analysis for FAST HI Intensity Mapping D…

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We demonstrate a frequency synchronization scheme with the phase noise compensation function placed at the client site. One transmitting module hence can be linked with multiple client sites. As a performance test, using two separate 50 km…

Optics · Physics 2014-09-12 Bo Wang , Xi Zhu , Chao Gao , Yu Bai , Jing Miao , Lijun Wang

High-resolution array detectors are widely used in single-particle tracking, but their performance is limited by excess noise from background light and dark current. As pixel resolution increases, the diminished signal per pixel exacerbates…

Quantum Physics · Physics 2025-12-16 Chao-Ning Hu , Jun Xin , Xiao-Ming Lu

We first study the solar flare time sequence based on the GOES16 data. We find that the power spectrum density of the low-energy (E\leq E_{mean}) flare shows 1/f fluctuations, but the high-energy (E>E_{mean}) flare shows a flat spectrum.…

Solar and Stellar Astrophysics · Physics 2023-10-12 Masahiro Morikawa , Akika Nakamichi

The correlation between the far-infrared (FIR) and radio emission is well established for nearby star forming galaxies. Many applications, in particular the radio-to-submm spectral index redshift indicator, tacitly assume that the relation…

Astrophysics · Physics 2007-05-23 M. A. Garrett

We report on a scanned superconducting quantum interference device (SQUID) microscope operating in a cryogen-free cryostat, with the capability of up to forty RF connections with 20 GHz bandwidth to a device under test. The system utilizes…

Superconductivity · Physics 2025-09-10 Ian W. Haygood , Bochao Xu , John Biesecker , Michael L. Schneider

HI intensity mapping is a new observational technique to map fluctuations in the large-scale structure of matter using the 21 cm emission line of atomic hydrogen (HI). Sensitive radio surveys have the potential to detect Baryon Acoustic…

Cosmology and Nongalactic Astrophysics · Physics 2017-11-22 L. C. Olivari , M. Remazeilles , C. Dickinson

We report the first measurement of 1/f type noise associated with electronic spin transport, using single layer graphene as a prototypical material with a large and tunable Hooge parameter. We identify the presence of two contributions to…

Mesoscale and Nanoscale Physics · Physics 2017-02-09 S. Omar , M. H. D. Guimarães , A. Kaverzin , B. J. van Wees , I. J. Vera-Marun

We report a direct measurement of the low-frequency noise spectrum in a superconducting flux qubit. Our method uses the noise sensitivity of a free-induction Ramsey interference experiment, comprising free evolution in the presence of noise…

We report on the realization of a high sensitivity RF noise measurement scheme to study small current fluctuations of mesoscopic systems at milliKelvin temperatures. The setup relies on the combination of an interferometric ampli- fication…

Mesoscale and Nanoscale Physics · Physics 2011-03-07 François D. Parmentier , Adrien Mahé , Anne Denis , Jean-Marc Berroir , D. Christian Glattli , Bernard Plaçais , Gwendal Fève

The $1/f$ noise is a ubiquitous phenomenon in natural systems. Since the advent of space exploration, the $1/f$ range has been consistently observed in \textit{in situ} solar wind measurements throughout the heliosphere, sparking decades of…

Solar and Stellar Astrophysics · Physics 2025-09-03 Zesen Huang , Marco Velli , B. D. G. Chandran , Chen Shi , Yuliang Ding , Lorenzo Matteini , Kyung-Eun Choi

When illuminated by a white light source, the discrete resonances of a Fabry-Perot interferometer (FP) provide a broad bandwidth, comb-like spectrum useful for frequency calibration. We report on the design, construction and laboratory…

Instrumentation and Methods for Astrophysics · Physics 2020-05-04 Jeff Jennings , Ryan Terrien , Connor Fredrick , Michael Grisham , Mark Notcutt , Samuel Halverson , Suvrath Mahadevan , Scott A. Diddams

We explore the feasibility of HI galaxy redshift surveys with the Five-hundred-meter Aperture Spherical Telescope (FAST) and its proposed Core Array interferometry. Using semi-analytical simulations, we compare the performance of the FAST…

Cosmology and Nongalactic Astrophysics · Physics 2025-08-25 Zhenglong Li , Diyang Liu , Chengliang Xu , Yichao Li , Xin Zhang

The presence of $1/f$ noise, also known as pink noise, is a well-established phenomenon in biological neural networks, and is thought to play an important role in information processing in the brain. In this study, we find that such $1/f$…

Data Analysis, Statistics and Probability · Physics 2024-04-02 Nicholas Chong Jia Le , Ling Feng

Line intensity mapping provides a statistical approach to tracing the large-scale distribution of matter in the Universe. We apply the HI intensity mapping technique to interferometric data from the MeerKAT International GHz-Tiered…

We investigate the possibility of probing the large scale structure in the universe at large redshifts by studying fluctuations in the redshifted 1420 MHz emission from the neutral hydrogen (HI) at early epochs. The neutral hydrogen content…

Astrophysics · Physics 2009-11-07 Somnath Bharadwaj , Shiv K. Sethi

Measurements of low-order p modes and gravity modes are perturbed by the solar convective background. Such perturbation increases below 2mHz for intensity measurements and 1mHz for velocity measurements. While the low-degree modes have…

Astrophysics · Physics 2008-10-10 R. A. Garcia , S. Mathur , I. Gonzalez Hernandez , A. Jimenez

In a sky-averaged 21-cm signal experiment, the uncertainty on the extracted signal depends mainly on the covariance between the foreground and 21-cm signal models. In this paper, we construct these models using the modes of variation…

Cosmology and Nongalactic Astrophysics · Physics 2023-04-19 Anchal Saxena , P. Daniel Meerburg , Eloy de Lera Acedo , Will Handley , Léon V. E. Koopmans

It is generally assumed that stochastic processes exhibiting 1/f noise are affected with the so-called infrared catastrophe. We present an intermittent stochastic process generating 1/f noise which avoids this problem.

Data Analysis, Statistics and Probability · Physics 2012-01-17 Ferdinand Grueneis

Aims: This paper discusses the spectral occupancy for performing radio astronomy with the Low-Frequency Array (LOFAR), with a focus on imaging observations. Methods: We have analysed the radio-frequency interference (RFI) situation in two…

Neutral hydrogen (HI) intensity mapping with single-dish experiments is a powerful approach for probing cosmology in the post-reionization epoch. However, the presence of bright foregrounds over four orders of magnitude stronger than the HI…

Cosmology and Nongalactic Astrophysics · Physics 2026-02-03 Athanasia Gkogkou , Victor Bonjean , Jean-Luc Starck , Marta Spinelli , Panagiotis Tsakalides