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Our previous work has demonstrated that Rayleigh model, which is widely used in polarized skylight navigation to describe skylight polarization patterns, does not contain three-dimensional (3D) attitude information [1]. However, it is still…

Image and Video Processing · Electrical Eng. & Systems 2020-12-17 Huaju Liang , Hongyang Bai , Tong Zhou

Quantum error correction can reduce the effects of noise in quantum systems, e.g. in metrology or most notably in quantum computing. Typically, this requires making measurements that provide information about the errors that have occurred…

Quantum Physics · Physics 2024-12-12 Christian Wimmer , Jochen Szangolies , Michael Epping

In the coming decade, a new generation of massively multiplexed spectroscopic surveys, such as PFS, WAVES, and MOONS, will probe galaxies in the distant universe in vastly greater numbers than was previously possible. In this work, we…

Artificial skyglow is constantly growing on a global scale, with potential ecological consequences ranging up to affecting biodiversity. To understand these consequences, worldwide mapping of skyglow for all weather conditions is urgently…

Instrumentation and Methods for Astrophysics · Physics 2017-09-12 Andreas Jechow , Zoltán Kolláth , Salvador J. Ribas , Henk Spoelstra , Franz Hölker , Christopher C. M. Kyba

We study the impact of sky-based calibration errors from source mismodeling on 21\,cm power spectrum measurements with an interferometer and propose a method for suppressing their effects. While emission from faint sources that are not…

Cosmology and Nongalactic Astrophysics · Physics 2017-07-26 Aaron Ewall-Wice , Joshua S. Dillon , Adrian Liu , Jacqueline Hewitt

Accurate classification of weather conditions in images is essential for enhancing the performance of object detection and classification models under varying weather conditions. This paper presents a comprehensive study on classifying…

Computer Vision and Pattern Recognition · Computer Science 2024-09-04 Eden Ship , Eitan Spivak , Shubham Agarwal , Raz Birman , Ofer Hadar

Gradient-based optimizers have been proposed for training variational quantum circuits in settings such as quantum neural networks (QNNs). The task of gradient estimation, however, has proven to be challenging, primarily due to distinctive…

(Abridged) We present new theoretical predictions for surface brightness fluctuations (SBFs) using models optimized for this purpose. Our predictions agree well with SBF data for globular clusters and elliptical galaxies. We provide refined…

Astrophysics · Physics 2009-10-31 Michael C. Liu , Stephane Charlot , James R. Graham

Despite its scientific importance, the low-surface-brightness universe has yet to be fully explored due to various systematic uncertainties that affect the achievable surface-brightness limit. Reducing these uncertainties requires very…

Instrumentation and Methods for Astrophysics · Physics 2025-04-22 Woowon Byun , Kwang-Il Seon , Jongwan Ko

Spectroscopic study of the night sky has been a common way to assess the impacts of artificial light at night at remote astronomical observatories. However, the spectroscopic properties of the urban night sky remain poorly documented. We…

Instrumentation and Methods for Astrophysics · Physics 2025-10-22 Chu Wing So , Chun Shing Jason Pun , Shengjie Liu

The low surface brightness (LSB) regime ($\mu_{g} \gtrsim 26$ mag arcsec$^{-2}$) comprises a vast, mostly unexplored discovery space, from dwarf galaxies to the diffuse interstellar medium. Accessing this regime requires precisely removing…

Astrophysics of Galaxies · Physics 2024-01-24 A. E. Watkins , S. Kaviraj , C. C. Collins , J. H. Knapen , L. S. Kelvin , P. -A. Duc , J. Román , J. C. Mihos

In the near future, the overlap of the Rubin Observatory Legacy Survey of Space and Time (LSST) and the Simons Observatory (SO) will present an ideal opportunity for joint cosmological dataset analyses. In this paper we simulate the joint…

Cosmology and Nongalactic Astrophysics · Physics 2021-12-06 Xiao Fang , Tim Eifler , Emmanuel Schaan , Hung-Jin Huang , Elisabeth Krause , Simone Ferraro

A high-precision calibration method for all-sky cameras has been realized using images from the Ali observatory in Tibet, providing application results for atmospheric extinction, night sky brightness, and known variable stars. This method…

Instrumentation and Methods for Astrophysics · Physics 2025-01-16 Jia Yin , Yongqiang Yao , Xuan Qian , Liyong Liu , Xu Chen , Liuming Zhai

Weak gravitational lensing provides a direct statistical measure of the dark matter distribution. The variance is easiest to measure, which constrains the degenerate product \sigma_8\Omega^0.6. The degeneracy is broken by measuring the…

The subject of this paper is a quantification of the impact of uncertainties in bias and bias evolution on the interpretation of measurements of the integrated Sachs-Wolfe effect, in particular on the estimation of cosmological parameters.…

Cosmology and Nongalactic Astrophysics · Physics 2013-03-07 Bjoern Malte Schaefer , Marian Douspis , Nabila Aghanim

Context. The presence of clouds during observations with Imaging Atmospheric Cherenkov Telescopes can strongly affect the performance of the instrument due to additional absorption of light and scattering of light beyond the field of view…

Instrumentation and Methods for Astrophysics · Physics 2024-05-22 Natalia Żywucka , Julian Sitarek , Dorota Sobczyńska , Mario Pecimotika , Dario Hrupec , Dijana Dominis Prester , Lovro Pavletić , Saša Mićanović

HQM is an optical broad-band photometric monitoring program carried out since Sept.~1988. We use a CCD camera equipped to the MPIA 1.2$\,$m telescope. Fully automatic photometric reduction relative to stars in the frames is done within a…

Astrophysics · Physics 2009-09-25 K. -J. Schramm , U. Borgeest , D. Kühl , J. v. Linde , M. D. Linnert

We propose a new observable for the 21cm global signal during the dark ages, the dark-age consistency ratio, which is motivated from the fact that the shape of the functional form of the brightness temperature against the frequency is…

Cosmology and Nongalactic Astrophysics · Physics 2023-09-14 Fumiya Okamatsu , Teppie Minoda , Tomo Takahashi , Daisuke Yamauchi , Shintaro Yoshiura

We report on the temporal and spatial fluctuations in the atmospheric brightness in the narrow band between Meinel emission lines at 1191.3 nm using an R=320 near-infrared instrument. We present the instrument design and implementation,…

Instrumentation and Methods for Astrophysics · Physics 2016-07-20 Hien T. Nguyen , Michael Zemcov , John Battle , James J. Bock , Viktor Hristov , Philip Korngut , Andrew Meek

The Swedish 1-m Solar Telescope (SST) offers excellent imaging quality, but it has a comparatively small field of view. This means that while observing the solar photosphere, there has been no convenient way of calibrating the image scale…

Instrumentation and Methods for Astrophysics · Physics 2013-11-21 Alexander Norén