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Coherent multiport interferometers are a promising approach to realize matrix multiplication in integrated photonics. However, most known architectures - such as MZI and beamsplitter meshes, as well as more general interferometers - suffer…

Optics · Physics 2025-08-01 Nikita A. Nemkov , Stanislav S. Straupe

The design and development process for the Square Kilometre Array (SKA) radio telescope, the Low Frequency Aperture Array component, was progressed during the SKA pre-construction phase by an international consortium, with the goal of…

We want to reconstruct a signal based on inhomogeneous data (the amount of data can vary strongly), using the model of regression with a random design. Our aim is to understand the consequences of inhomogeneity on the accuracy of estimation…

Statistics Theory · Mathematics 2016-08-16 Stéphane Gaiffas

HERA is a highly-redundant transit interferometer with 14\,m-diameter parabolic dish elements. We exploit the fact that the Galactic centre transits through the main beam of the telescope to attempt a conventional self-calibration approach…

Instrumentation and Methods for Astrophysics · Physics 2017-09-18 Bojan Nikolic , Chris Carilli , HERA Collaboration

Back-illuminated charged-coupled device (BI-CCD) arrays increase quantum efficiency but also amplify etaloning, a multiplicative, wavelength-dependent fixed-pattern effect. When spectral data from hundreds of BI-CCD rows are combined, the…

Optics · Physics 2021-07-26 Christine Massie , Keren Chen , Andrew J. Berger

Model calibration consists of using experimental or field data to estimate the unknown parameters of a mathematical model. The presence of model discrepancy and measurement bias in the data complicates this task. Satellite interferograms,…

Methodology · Statistics 2023-02-28 Mengyang Gu , Kyle Anderson , Erika McPhillips

Clustering is widely used for unsupervised structure discovery, yet it offers limited insight into how reliable each individual assignment is. Diagnostics, such as convergence behavior or objective values, may reflect global quality, but…

Machine Learning · Computer Science 2026-05-15 Aggelos Semoglou , John Pavlopoulos

Radiometers are crucial instruments in radio astronomy, forming the primary component of nearly all radio telescopes. They measure the intensity of electromagnetic radiation, converting this radiation into electrical signals. A radiometer's…

Strain in a material induces shifts in vibrational frequencies, which is a probe of the nature of the vibrations and interatomic potentials, and can be used to map local stress/strain distributions via Raman microscopy. This method is…

The very demanding requirements of the SKA-low instrument call for a challenging antenna design capable of delivering excellence performance in radiation patterns, impedance matching, polarization purity, cost, longevity, etc. This paper is…

Instrumentation and Methods for Astrophysics · Physics 2015-12-07 E. de Lera Acedo , N. Razavi-Ghods , N. Troop , N. Drought , A. J. Faulkner

For radio interferometric arrays with a sufficient number of redundant spacings the multiplicity of measurements of the same sky visibility can be used to determine both the antenna gains as well as the true visibilities. Many of the…

Instrumentation and Methods for Astrophysics · Physics 2013-10-08 Visweshwar Ram Marthi , Jayaram Chengalur

This decade, the Square Kilometre Array (SKA) will perform its first observations. Preparations for building dishes, antennas, correlators and infrastructure are well underway. Concurrently, software for the processing of SKA observations…

Instrumentation and Methods for Astrophysics · Physics 2020-11-02 H. Spreeuw , S. Yatawatta , B. Van Werkhoven , F. Diblen

Shallow ensembles provide a convenient strategy for uncertainty quantification in machine learning interatomic potentials, that is computationally efficient because the different ensemble members share a large part of the model weights. In…

Chemical Physics · Physics 2026-02-18 Moritz Schäfer , Matthias Kellner , Johannes Kästner , Michele Ceriotti

The performance of spectral clustering heavily relies on the quality of affinity matrix. A variety of affinity-matrix-construction (AMC) methods have been proposed but they have hyperparameters to determine beforehand, which requires strong…

Machine Learning · Computer Science 2023-02-07 Jicong Fan , Yiheng Tu , Zhao Zhang , Mingbo Zhao , Haijun Zhang

We present a new procedure for the internal (night-to-night) calibration of time series spectra, with specific applications to optical AGN reverberation mapping data. The traditional calibration technique assumes that the narrow…

Instrumentation and Methods for Astrophysics · Physics 2017-12-19 M. M. Fausnaugh

The Infrared Array Camera (IRAC) on the Spitzer Space Telescope is absolutely calibrated by comparing photometry on a set of A stars near the north ecliptic pole to predictions based on ground-based observations and a stellar atmosphere…

Regularization of the inverse problem is a complex issue when using Near-field Acoustic Holography (NAH) techniques to identify the vibrating sources. This paper shows that, for convex homogeneous plates with arbitrary boundary conditions,…

Data Analysis, Statistics and Probability · Physics 2015-06-05 Gilles Chardon , Laurent Daudet , Antoine Peillot , François Ollivier , Nancy Bertin , Rémi Gribonval

Programmable linear optical interferometers are promising for classical and quantum applications. Their integrated design makes it possible to create more scalable and stable devices. To use them in practice, one has to reconstruct the…

Quantum Physics · Physics 2024-01-12 B. I. Bantysh , A. Yu. Chernyavskiy , S. A. Fldzhyan , Yu. I. Bogdanov

The wavelength calibration of spectrographs is an essential but challenging task in many disciplines. Calibration is traditionally accomplished by imaging the spectrum of a light source containing features that are known to appear at…

Instrumentation and Methods for Astrophysics · Physics 2018-04-04 Neil Thomas

Quantitative inversion algorithms allow for the reconstruction of electrical properties (such as permittivity, and conductivity) for every point in a scene. However, they are challenging to use on measured datasets due to the need to know…

Signal Processing · Electrical Eng. & Systems 2025-05-15 Zacharie Idriss , Raghu Raj
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