English
Related papers

Related papers: Circuit Modeling for In Situ 21 cm Radiometer Cali…

200 papers

The 21-cm signal from neutral hydrogen is anticipated to reveal critical insights into the formation of early cosmic structures during the Cosmic Dawn and the subsequent Epoch of Reionization. However, the intrinsic faintness of the signal,…

Cosmology and Nongalactic Astrophysics · Physics 2026-05-27 Yuchen Liu , Eloy de Lera Acedo , Peter Sims

Understanding dark energy requires precision measurements of the expansion history of the universe and the growth of large-scale structure. The 21 cm intensity mapping (21 cm IM) technique enables rapid large-area surveys that can deliver…

Cosmology and Nongalactic Astrophysics · Physics 2025-11-25 Jun-Da Pan , Yichao Li , Guo-Hong Du , Tian-Nuo Li , Xin Zhang

Calibration is commonly evaluated by comparing model confidence with its empirical correctness, implicitly treating reliability as a function of the confidence score alone. However, this view can hide substantial structure: models may be…

Machine Learning · Computer Science 2026-05-14 Katarzyna Kobalczyk , Mihaela van der Schaar

High-redshift 21-cm observations will provide crucial insights into the physical processes of the Epoch of Reionization. Next-generation interferometers such as the Square Kilometer Array will have enough sensitivity to directly image the…

Cosmology and Nongalactic Astrophysics · Physics 2021-01-27 Simon Gazagnes , Léon V. E. Koopmans , Michael H. F. Wilkinson

Improved miniaturization capabilities for complex fisheye camera systems have recently led to the introduction of many compact 360-degree cameras on the consumer technology market. Designed primarily for recreational photography, several…

Bistatic radar measurements offer unique spatial diversity and enhanced target characterization capabilities, rendering them increasingly vital for contemporary sensing application research. The reliability of such measurements is…

The EDGES collaboration has reported the detection of a global 21-cm signal with a plateau centered at 76 MHz (i.e., redshift 17.2), with an amplitude of 500^(+200)_(-500) mK. This anomalous measurement does not comport with standard…

Cosmology and Nongalactic Astrophysics · Physics 2021-03-22 Fulvio Melia

The homogeneity scale, $R_{\rm H}$, offers a fundamental test of the Cosmological Principle, yet it has not yet been measured with 21cm intensity mapping surveys. A key limitation for such a measurement is the telescope beam, which…

Cosmology and Nongalactic Astrophysics · Physics 2026-05-27 Bruno B. Bizarria , Camila P. Novaes , Felipe Avila , Rahima Mokeddem , Helissa H. da Costa , Carlos A. Wuensche , Gabriel A. S. Silva

The redshifted 21 cm line is an emerging tool in cosmology, in principle permitting three-dimensional surveys of our Universe that reach unprecedentedly large volumes, previously inaccessible length scales, and hitherto unexplored epochs of…

Instrumentation and Methods for Astrophysics · Physics 2020-04-27 Adrian Liu , J. Richard Shaw

Calibrating telescope data is one of the most important issues an observer faces. In this chapter we describe a number of the methods which are commonly used to calibrate radio telescope data in the centimeter wavelength regime. This…

Astrophysics · Physics 2007-05-23 K. O'Neil

The reliable detection of the global 21-cm signal, a key tracer of Cosmic Dawn and the Epoch of Reionization, requires meticulous data modelling and robust statistical frameworks for model validation and comparison. In Paper I of this…

A key factor in ensuring the accuracy of computer simulations that model physical systems is the proper calibration of their parameters based on real-world observations or experimental data. Inevitably, uncertainties arise, and Bayesian…

Computational Engineering, Finance, and Science · Computer Science 2026-02-25 Daniel Andrés Arcones , Martin Weiser , Phaedon-Stelios Koutsourelakis , Jörg F. Unger

This chapter aims to provide a review of the basics of 21 cm interferometric observations and its methodologies. A summary of the main concepts of radio interferometry and their connection with the 21 cm observables - power spectra and…

Instrumentation and Methods for Astrophysics · Physics 2019-09-27 G. Bernardi

Foreground removal presents a significant obstacle in both current and forthcoming intensity mapping surveys. While numerous techniques have been developed that show promise in simulated datasets, their efficacy often diminishes when…

Cosmology and Nongalactic Astrophysics · Physics 2024-08-14 Jiacheng Ding , Xin Wang , Ue-Li Pen , Xiao-Dong Li

Due to the large dynamic ranges involved with separating the cosmological 21-cm signal from the Cosmic Dawn from galactic foregrounds, a well-calibrated instrument is essential to avoid biases from instrumental systematics. In this paper we…

Models of physical systems are used to explain and predict experimental results and observations. When students encounter discrepancies between the actual and expected behavior of a system, they revise their models to include the newly…

Physics Education · Physics 2022-07-06 Laura Ríos , Benjamin Pollard , Dimitri R. Dounas-Frazer , H. J. Lewandowski

Depth cameras, typically in RGB-D configurations, are common devices in mobile robotic platforms given their appealing features: high frequency and resolution, low price and power requirements, among others. These sensors may come with…

Robotics · Computer Science 2019-07-04 David Zuñiga-Noël , Jose-Raul Ruiz-Sarmiento , Javier Gonzalez-Jimenez

The global 21 cm signal from Cosmic Dawn (CD) and the Epoch of Reionization (EoR), at redshifts $z \sim 6-30$, probes the nature of first sources of radiation as well as physics of the Inter-Galactic Medium (IGM). Given that the signal is…

Instrumentation and Methods for Astrophysics · Physics 2018-04-25 Saurabh Singh , Ravi Subrahmanyan , N. Udaya Shankar , Mayuri Sathyanarayana Rao , B. S. Girish , A. Raghunathan , R. Somashekar , K. S. Srivani

Detections of the cross correlation signal between the 21cm signal during reionization and high-redshift Lyman Alpha emitters (LAEs) are subject to observational uncertainties which mainly include systematics associated with radio…

Cosmology and Nongalactic Astrophysics · Physics 2018-07-04 Anne Hutter , Cathryn M. Trott , Pratika Dayal

Many mobile robotic platforms rely on an accurate knowledge of the extrinsic calibration parameters, especially systems performing visual stereo matching. Although a number of accurate stereo camera calibration methods have been developed,…