English
Related papers

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

200 papers

We propose a simple method to estimate the parameters of a continuously measured quantum system, by fitting correlation functions of the measured signal. We demonstrate the approach in simulation, both on toy examples and on a recent…

Quantum Physics · Physics 2024-10-17 Pierre Guilmin , Pierre Rouchon , Antoine Tilloy

In 21-cm experimental cosmology, accurate characterization of a radio telescope's antenna beam response is essential to measure the 21-cm signal. Computational electromagnetic (CEM) simulations estimate the antenna beam pattern and…

Instrumentation and Methods for Astrophysics · Physics 2024-08-30 Joshua J. Hibbard , Bang D. Nhan , David Rapetti , Jack O. Burns

The classical radiometer equation is commonly used to calculate the detectability of the 21cm emission by diffuse cosmic hydrogen at high redshifts. However, the classical description is only valid in the regime where the occupation number…

Astrophysics · Physics 2009-06-23 Abraham Loeb

The central challenge in 21~cm cosmology is isolating the cosmological signal from bright foregrounds. Many separation techniques rely on the accurate knowledge of the sky and the instrumental response, including the antenna primary beam.…

Cosmological probes pose an inverse problem where the measurement result is obtained through observations, and the objective is to infer values of model parameters which characterize the underlying physical system -- our Universe. Modern…

Instrumentation and Methods for Astrophysics · Physics 2019-05-21 Timur Takhtaganov , Zarija Lukic , Juliane Mueller , Dmitriy Morozov

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

Precise instrument calibration is critical to the success of 21 cm Cosmology experiments. Unmitigated errors in calibration contaminate the Epoch of Reionization (EoR) signal, precluding a detection. Barry et al. 2016 characterizes one…

Instrumentation and Methods for Astrophysics · Physics 2019-04-24 Ruby Byrne , Miguel F. Morales , Bryna Hazelton , Wenyang Li , Nichole Barry , Adam P. Beardsley , Ronniy Joseph , Jonathan Pober , Ian Sullivan , Cathryn Trott

Calibration parameters in deterministic computer experiments are those attributes that cannot be measured or available in physical experiments. Kennedy and O'Hagan \cite{kennedy2001bayesian} suggested an approach to estimate them by using…

Methodology · Statistics 2015-08-31 Rui Tuo , C. F. Jeff Wu

Detecting the redshifted global 21-cm signal from the cosmic dawn (CD) remains a major challenge due to strong terrestrial Radio Frequency Interference (RFI), particularly dominated by Frequency Modulation (FM) transmissions in the 88-110…

Instrumentation and Methods for Astrophysics · Physics 2026-05-22 Yogen Pranesh , Mayuri Sathyanarayana Rao , Saurabh Singh

We introduce an improved microwave calibration method for use in a cryogenic environment, based on a traditional three-standard calibration, the Thru-Reflect-Line (TRL) calibration. The modified calibration method takes advantage of…

Instrumentation and Detectors · Physics 2013-03-27 Jen-Hao Yeh , Steven M. Anlage

Emulation of the Global (sky-averaged) 21-cm signal with neural networks has been shown to be an essential tool for physical signal modelling. In this paper we present globalemu, a Global 21-cm signal emulator that uses redshift as a…

Cosmology and Nongalactic Astrophysics · Physics 2021-10-18 H. T. J. Bevins , W. J. Handley , A. Fialkov , E. de Lera Acedo , K. Javid

Spectral distortions in the cosmic microwave background over the 40--200~MHz band are imprinted by neutral hydrogen in the intergalactic medium prior to the end of reionization. This signal, produced in the redshift range $z = 6-34$ at the…

We propose the implementation of an imaging telescope in combination with an inter-frequency calibrator to measure the spectral shape of the microwave sky by exploiting the differences in the sky intensity between multiple pairs of…

Cosmology and Nongalactic Astrophysics · Physics 2020-02-25 Suvodip Mukherjee , Joseph Silk , Benjamin D. Wandelt

This paper develops a Bayesian network-based method for the calibration of multi-physics models, integrating various sources of uncertainty with information from computational models and experimental data. We adopt the Kennedy and O'Hagan…

Data Analysis, Statistics and Probability · Physics 2012-06-25 You Ling , Joshua Mullins , Sankaran Mahadevan

Precise measurements of the 21 cm power spectrum are crucial for understanding the physical processes of hydrogen reionization. Currently, this probe is being pursued by low-frequency radio interferometer arrays. As these experiments come…

Using high redshift radio sources as background, the 21cm forest observations probe the neutral hydrogen absorption signatures of early structures along the lines of sight. Directly sensitive to the spin temperature, it complements the 21cm…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-18 Yidong Xu , Xuelei Chen , Zuhui Fan , Hy Trac , Renyue Cen

Identification of model parameters in computer simulations is an important topic in computer experiments. We propose a new method, called the projected kernel calibration method, to estimate these model parameters. The proposed method is…

Methodology · Statistics 2017-05-10 Rui Tuo

Measurements of the post-reionization 21-cm bispectrum $B_{{\rm HI}}(\mathbf{k_1},\mathbf{k_2},\mathbf{k_3})$ using various upcoming intensity mapping experiments hold the potential for determining the cosmological parameters at a high…

Cosmology and Nongalactic Astrophysics · Physics 2019-10-16 Debanjan Sarkar , Suman Majumdar , Somnath Bharadwaj

The redshifted 21 cm line of cosmic atomic hydrogen is one of the most auspicious tools in deciphering the early Universe. Recovering this signal remains an ongoing problem for cosmologists in the field, with the signal being hidden behind…

Cosmology and Nongalactic Astrophysics · Physics 2024-09-18 Joe H. N. Pattison , Jean Cavillot , Harry T. J. Bevins , Dominic J. Anstey , Eloy de Lera Acedo

Channel measurements in MIMO systems hinge on precise synchronization. While methods for time and frequency synchronization are well established, maintaining real-time phase coherence remains an open requirement for many MIMO systems. Phase…

Signal Processing · Electrical Eng. & Systems 2026-02-19 Carl Collmann , Ahmad Nimr , Gerhard Fettweis