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Sky models have been used in the past to calibrate individual low radio frequency telescopes. Here we generalize this approach from a single antenna to a two element interferometer and formulate the problem in a manner to allow us to…

Instrumentation and Methods for Astrophysics · Physics 2017-06-28 Divya Oberoi , Rohit Sharma , Alan E. E. Rogers

Atom interferometery is an exquisite measurement technique sensitive to inertial forces. However, it is commonly limited to a single sensitive axis, allowing high-precision multi-dimensional sensing only through subsequent or post-corrected…

The principles and practice of astronomical imaging Fourier transform spectroscopy (FTS) at far-infrared wavelengths are described. The Mach-Zehnder interferometer design has been widely adopted for current and future imaging FTS…

Instrumentation and Methods for Astrophysics · Physics 2013-10-10 David A. Naylor , Brad G. Gom , Matthijs H. D. van der Wiel , Gibion Makiwa

The "Tapered Gridded Estimator" (TGE) is a novel way to directly estimate the angular power spectrum from radio-interferometric visibility data that reduces the computation by efficiently gridding the data, consistently removes the noise…

Cosmology and Nongalactic Astrophysics · Physics 2017-07-27 Samir Choudhuri , Nirupam Roy , Somnath Bharadwaj , Sk. Saiyad Ali , Abhik Ghosh , Prasun Dutta

We present a fast algorithm for computing the diffracted field from arbitrary binary (sharp-edged) planar apertures and occulters in the scalar Fresnel approximation, for up to moderately high Fresnel numbers ($\lesssim 10^3$). It uses a…

Instrumentation and Methods for Astrophysics · Physics 2020-12-18 Alex H. Barnett

The calibration procedures for data collected for Argus and the 4mm Receiver instruments on the GBT are presented. The measured beam size, aperture efficiency, and main-beam efficiency are derived for the range of observing frequencies…

Instrumentation and Methods for Astrophysics · Physics 2019-06-07 David T. Frayer , Ronald J. Maddalena , Steven White , Galen Watts , Amanda Kepley , Jialu Li , Andrew I. Harris

Long-baseline optical interferometry uses the power spectrum and bispectrum constructs as fundamental observables. Noise arising in the detection of the fringe pattern gives rise to both variance and biases in the power spectrum and…

Instrumentation and Methods for Astrophysics · Physics 2015-05-28 J. A. Gordon , D. F. Buscher

Near-field communications present new opportunities over near-field channels, however, the spherical wavefront propagation makes near-field signal processing challenging. In this context, this paper proposes efficient near-field channel…

Information Theory · Computer Science 2023-04-04 Songjie Yang , Chenfei Xie , Wanting Lyu , Boyu Ning , Zhongpei Zhang , Chau Yuen

We present a reference-free computational wavefront sensor based on binary amplitude modulation and phase retrieval. The method employs Digital Micro-mirror Device as a programmable amplitude modulator and reconstructs the complex optical…

Optics · Physics 2026-02-12 Ondrej Denk , Jan Pilar , Martin Divoky , Miroslav Cech , Tomas Mocek

In wideband millimeter wave (mmWave) massive multiple-input multiple-output (MIMO) systems, channel estimation is challenging due to the hybrid analog-digital architecture, which compresses the received pilot signal and makes channel…

Information Theory · Computer Science 2023-02-02 Jiabao Gao , Caijun Zhong , Geoffrey Ye Li

We derive optimal estimators for the two-, three-, and four-point correlators of statistically isotropic scalar fields defined on the sphere, such as the Cosmic Microwave Background temperature fluctuations, allowing for arbitrary (linear)…

Cosmology and Nongalactic Astrophysics · Physics 2023-06-28 Oliver H. E. Philcox

Several theoretical waveform models have been developed over the years to capture the gravitational wave emission from the dynamical evolution of compact binary systems of neutron stars and black holes. As ground-based detectors improve…

General Relativity and Quantum Cosmology · Physics 2024-10-02 Lalit Pathak , Amit Reza , Anand S. Sengupta

The Fourier transform spectrometer (FTS) is a core instrument for solar observation with high spectral resolution, especially in the infrared. The Infrared System for the Accurate Measurement of Solar Magnetic Field (AIMS), working at 10-13…

Solar and Stellar Astrophysics · Physics 2021-12-08 Xianyong Bai , Zhiyong Zhang , Zhiwei Feng , Yuanyong Deng , Xingming Bao , Xiao Yang , Yongliang Song , Liyue Tong , Shuai Jing

Wireless communications at high-frequency bands with large antenna arrays face challenges in beam management, which can potentially be improved by multimodality sensing information from cameras, LiDAR, radar, and GPS. In this paper, we…

Signal Processing · Electrical Eng. & Systems 2023-09-22 Yu Tian , Qiyang Zhao , Zine el abidine Kherroubi , Fouzi Boukhalfa , Kebin Wu , Faouzi Bader

The Murchison Widefield Array (MWA) is a low-frequency aperture array capable of high-time and frequency resolution astronomy applications such as pulsar studies. The large field-of-view of the MWA (hundreds of square degrees) can also be…

Instrumentation and Methods for Astrophysics · Physics 2022-05-18 N. A. Swainston , N. D. R. Bhat , I. S. Morrison , S. J. McSweeney , S. M. Ord , S. E. Tremblay , M. Sokolowski

The Fast Aerosol Spectrometer (FASP) is a device for spectral aerosol measurements. Its purpose is to safely monitor the atmosphere inside a reactor containment. First we describe the FASP and explain its basic physical laws. Then we…

Numerical Analysis · Mathematics 2017-01-17 Tobias Kyrion , Graham Alldredge

Recent interferometric observations by the Event Horizon Telescope have resolved the horizon-scale emission from sources in the vicinity of nearby supermassive black holes. Future space-based interferometers promise to measure the "photon…

General Relativity and Quantum Cosmology · Physics 2024-06-06 Alejandro Cárdenas-Avendaño , Alexandru Lupsasca , Hengrui Zhu

Context. Accurate long-baseline interferometric measurements require careful calibration with reference stars. Small calibrators with high angular diameter accuracy ensure the true visibility uncertainty to be dominated by the measurement…

Instrumentation and Methods for Astrophysics · Physics 2010-03-24 P. Cruzalebes , A. Jorissen , S. Sacuto , D. Bonneau

We investigate the retrieval of a binary time-frequency mask from a few observations of filtered white ambient noise. Confirming household wisdom in acoustic modeling, we show that this is possible by inspecting the average spectrogram of…

Sound · Computer Science 2024-02-05 José Luis Romero , Michael Speckbacher

Subtraction of astrophysical foreground contamination from "dirty" sky maps produced by simulated measurements of the Murchison Widefield Array (MWA) has been performed by fitting a 3rd-order polynomial along the spectral dimension of each…

Astrophysics · Physics 2011-02-11 Judd D. Bowman , Miguel F. Morales , Jacqueline N. Hewitt