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We present an assessment of the accuracy of common operations performed in $21$-cm spectral line stacking experiments. To this end, we generate mock interferometric data surveying the 21-cm emission at frequency $1310<\nu<1420$ MHz…

Cosmology and Nongalactic Astrophysics · Physics 2022-06-22 Francesco Sinigaglia , Ed Elson , Giulia Rodighiero , Mattia Vaccari

We review millimeter interferometric phase variations caused by variations in the precipitable water vapor content of the troposphere, and we discuss techniques proposed to correct for these variations. We present observations with the Very…

Astrophysics · Physics 2015-06-24 C. L. Carilli , M. A. Holdaway

Interferometers require accurate determination of the array configuration in order to produce reliable observations. A method is presented for finding the maximum-likelihood estimate of the telescope geometry, and of other instrumental…

Astrophysics · Physics 2009-11-07 Klaus Maisinger , M. P. Hobson , Richard D. E. Saunders , Keith J. B. Grainge

We present numerical simulations of the impact of laser beam wavefront aberrations in cold atom interferometers. We demonstrate that to reach accuracy at the mrad level, simulations cannot be based on a description of the retroreflection…

Atomic Physics · Physics 2025-05-15 Louis Pagot , Sébastien Merlet , Franck Pereira dos Santos

All observations by the aperture photometer (PHT-P) and the far-infrared (FIR) camera section (PHT-C) of ISOPHOT included reference measurements against stable internal fine calibration sources (FCS) to correct for temporal drifts in…

The space astrometry mission GAIA will construct a dense optical QSO-based celestial reference frame. For consistency between optical and radio positions, it will be important to align the GAIA frame and the International Celestial…

Astrophysics · Physics 2008-12-18 G. Bourda , P. Charlot , R. Porcas , S. Garrington

The detection of the primordial $B$-mode spectrum of the polarized cosmic microwave background (CMB) signal may provide a probe of inflation. However, observation of such a faint signal requires excellent control of systematic errors.…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-15 Ata Karakci , Le Zhang , P. M. Sutter , Emory F. Bunn , Andrei Korotkov , Peter Timbie , Gregory S. Tucker , Benjamin D. Wandelt

Polarimetric observations at sub-GHz frequencies offer unique access to the magnetized universe through Faraday rotation and depolarization studies, but achieving reliable polarization calibration at these frequencies remains challenging.…

Instrumentation and Methods for Astrophysics · Physics 2026-05-25 Arpan Pal , Sanjeet Rai , Ganesh Kumbhar

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

New and upcoming radio interferometers will produce unprecedented amounts of data that demand extremely powerful computers for processing. This is a limiting factor due to the large computational power and energy costs involved. Such…

Instrumentation and Methods for Astrophysics · Physics 2018-01-31 Sarod Yatawatta , Faruk Diblen , Hanno Spreeuw , L. V. E. Koopmans

In many polarimetry applications, including observations in the X-ray band, the measurement of a polarization signal can be reduced to the detection and quantification of a deviation from uniformity of a distribution of measured angles. We…

Instrumentation and Methods for Astrophysics · Physics 2015-06-16 Tod E. Strohmayer , Tim R. Kallman

Polarization calibration of interferometric observations is a costly procedure and, in some cases (e.g., a limited coverage of parallactic angle for the calibrator), it may not be possible to be performed. To avoid this worst-case scenario…

Instrumentation and Methods for Astrophysics · Physics 2023-04-05 E. Albentosa-Ruiz , I. Marti-Vidal

This paper is devoted to the primary spectro-polarimetric observation performed at the New Vacuum Solar Telescope of China since 2017, and our aim is to precisely evaluate the real polarimetric accuracy and sensitivity of this polarimetry…

Solar and Stellar Astrophysics · Physics 2020-05-06 Jun-Feng Hou , Zhi Xu , Shu Yuan , Yu-Chao Chen , Jian-Guo Peng , Dong-Guang Wang , Jun Xu , Yuan-Yong Deng , Zhen-Yu Jin , Kai-Fan Ji , Zhong Liu

Accurate LiDAR-Camera (LC) calibration is challenging but crucial for autonomous systems and robotics. In this paper, we propose two single-shot and target-less algorithms to estimate the calibration parameters between LiDAR and camera…

Robotics · Computer Science 2026-01-05 Yanyu Zhang , Jie Xu , Wei Ren

The wavelength dependence of atmospheric refraction causes elongation of finite-bandwidth images along the elevation vector, which produces spurious signals in weak gravitational lensing shear measurements unless this atmospheric dispersion…

Instrumentation and Methods for Astrophysics · Physics 2015-06-04 Andrés A. Plazas , Gary M. Bernstein

21 cm Epoch of Reionization observations promise to transform our understanding of galaxy formation, but these observations are impossible without unprecedented levels of instrument calibration. We present end-to-end simulations of a full…

Instrumentation and Methods for Astrophysics · Physics 2016-06-09 N. Barry , B. Hazelton , I. Sullivan , M. F. Morales , J. C. Pober

Aims. This research note presents a full analysis of the CAFOS polarimeter mounted at the Calar Alto 2.2m telescope. It also provides future users of this mode with all necessary information to properly correct for instrumental effects in…

Instrumentation and Methods for Astrophysics · Physics 2015-05-27 F. Patat , S. Taubenberger

Calibration of a typical radio interferometric array yields thousands of parameters as solutions. These solutions contain valuable information about the systematic errors in the data (ionosphere and beam shape). This information could be…

Instrumentation and Methods for Astrophysics · Physics 2018-01-31 Sarod Yatawatta

The separation of cosmological signal from astrophysical foregrounds is a fundamental challenge for any effort to probe the evolution of neutral hydrogen during the Cosmic Dawn and epoch of reionization (EoR) using the 21 cm hyperfine…

Cosmology and Nongalactic Astrophysics · Physics 2019-05-31 Naomi Orosz , Joshua S. Dillon , Aaron Ewall-Wice , Aaron R. Parsons , Nithyanandan Thyagarajan

Polarization from active galactic nuclei is interpreted as a signpost of the role of magnetic fields in the launch and collimation of their relativistic radio jets. Here, we report the detection of a clear polarization signal from ALMA…

Astrophysics of Galaxies · Physics 2018-12-26 I. Marti-Vidal , S. Muller