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The redshifted 21 cm line of neutral hydrogen is a promising probe of the Epoch of Reionization (EoR). However, its detection requires a thorough understanding and control of the systematic errors. We study two systematic biases observed in…

This paper indicates that the sensitivity and accuracy of an infrared radiometer for emissivity measurements depends not only on its design and the measurement method, but also on the spurious radiation. This spurious radiation must be…

Photonic integrated circuits offer a compact and stable platform for generating, manipulating, and detecting light. They are instrumental for classical and quantum applications. Imperfections stemming from fabrication constraints,…

One of the aims of next generation optical interferometric instrumentation is to be able to make use of information contained in the visibility phase to construct high dynamic range images. Radio and optical interferometry are at the two…

To achieve the sensitivity required to detect signals from neutral hydrogen from the Cosmic Dawn and Epoch of Reionisation it is critical to have a well-calibrated instrument which has a stable calibration over the course of the…

Instrumentation and Methods for Astrophysics · Physics 2026-03-04 Christian J. Kirkham , Dominic J. Anstey , Eloy de Lera Acedo

The accumulation of aberrations along the optical path in a telescope produces distortions and speckles in the resulting images, limiting the performance of cameras at high angular resolution. It is important to achieve the highest possible…

Instrumentation and Methods for Astrophysics · Physics 2021-03-17 Benjamin J. S. Pope , Laurent Pueyo , Yinzi Xin , Peter G. Tuthill

High precison calibration is essential for a new generation of radio interferometers looking for Epoch of Reionization and Baryon Acoustic Oscillation signatures in neutral hydrogen. These arrays have so far been calibrated by redundant…

Instrumentation and Methods for Astrophysics · Physics 2017-01-10 J. L. Sievers

Foreground mitigation is critical to all next-generation radio interferometers that target cosmology using the redshifted neutral hydrogen 21 cm emission line. Attempts to remove this foreground emission have led to new analysis techniques…

Instrumentation and Methods for Astrophysics · Physics 2022-11-22 Kalyani Bhopi , Will Tyndall , Pranav Sanghavi , Kevin Bandura , Laura Newburgh , Jason Gallicchio

Instruments for radio astronomical observations have come a long way. While the first telescopes were based on very large dishes and 2-antenna interferometers, current instruments consist of dozens of steerable dishes, whereas future…

Instrumentation and Methods for Astrophysics · Physics 2015-03-13 Stefan J. Wijnholds , Sebastiaan van der Tol , Ronald Nijboer , Alle-Jan van der Veen

Interferometric scattering microscopy (iSCAT) can image the dynamics of nanometer-scale systems. The typical approach to analyzing interferometric images involves intensive processing, which discards data and limits the precision of…

A probabilistic model is said to be calibrated if its predicted probabilities match the corresponding empirical frequencies. Calibration is important for uncertainty quantification and decision making in safety-critical applications. While…

Machine Learning · Computer Science 2020-07-01 Anusri Pampari , Stefano Ermon

New generation of radio interferometers are envisaged to produce high quality, high dynamic range Stokes images of the observed sky from the corresponding under-sampled Fourier domain measurements. In practice, these measurements are…

Instrumentation and Methods for Astrophysics · Physics 2020-01-08 Jasleen Birdi , Audrey Repetti , Yves Wiaux

This paper studies a robust design problem for far-field line-of-sight (LOS) channels where phase errors are present. Compared with the commonly used additive error model, the phase error model is more suitable for capturing the uncertainty…

Information Theory · Computer Science 2016-06-29 Man-Chung Yue , Sissi Xiaoxiao Wu , Anthony Man-Cho So

The HI 21cm global signal from the Cosmic Dawn and the Epoch of Reionization (EoR) offers critical insights into the evolution of our Universe. Yet, its detection presents significant challenges due to its extremely low…

Cosmology and Nongalactic Astrophysics · Physics 2024-04-09 Yue Wang , Xin Wang , Shijie Sun , Fengquan Wu , Shoudong Luo , Xuelei Chen

Photometric instruments operating at far infrared to millimetre wavelengths often have broad spectral passbands (central wavelength/bandwidth ~ 3 or less), especially those operating in space. A broad passband can result in significant…

A new physically based method to estimate hemispheric-directional reflectance factor (HDRF) from lightweight multispectral cameras that have a downwelling irradiance sensor is presented. It combines radiometry with photogrammetric computer…

Data Analysis, Statistics and Probability · Physics 2019-05-10 Klaus Schneider-Zapp , Manuel Cubero-Castan , Dai Shi , Christoph Strecha

The fundamental mechanism driving MIMO beamforming is the relative phases of signals departing the transmit array and arriving at the receive array. If a propagation channel affects all transmitted signals equally, the relative phases are a…

Signal Processing · Electrical Eng. & Systems 2026-01-21 Oliver Kirkpatrick , Santiago Ozafrain , Christopher Gilliam , Beth Jelfs

Knowledge of the spectrograph's instrumental profile (IP) provides important information needed for wavelength calibration and for the use in scientific analyses. This work develops new methods for IP reconstruction in high resolution…

Instrumentation and Methods for Astrophysics · Physics 2024-02-07 Dinko Milaković , Prashin Jethwa

The spatial coherence wavefront outer scale (L_0) characterizes the size of the largest turbulence eddies in Earth's atmosphere, determining low spatial frequency perturbations in the wavefront of the light captured by ground-based…

Instrumentation and Methods for Astrophysics · Physics 2024-07-03 Begoña García-Lorenzo , Donaji Esparza-Arredondo , Jose A. Acosta-Pulido , Julio A. Castro-Almazán