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Many aspects of the Atacama Large Millimeter Array (ALMA) instrument are still unknown due to its young age. One such aspect is the true nature of the primary beam of each baseline, and how changes to the individual primary beams affect…

Instrumentation and Methods for Astrophysics · Physics 2017-02-07 Kara Kundert , Urvashi Rau , Edwin Bergin , Sanjay Bhatnagar

The raw outputs of the detectors within the Advanced Laser Interferometer Gravitational-Wave Observatory need to be calibrated in order to produce the estimate of the dimensionless strain used for astrophysical analyses. The two detectors…

Calibration is one of the long-standing problems in optical interferometric measurements, particularly with long baselines which demand stars with angular sizes on the milliarcsecond scale and no detectable companions. While systems of…

Instrumentation and Methods for Astrophysics · Physics 2012-12-05 A. Richichi , O. Fors , F. Cusano , M. Moerchen

Atmospheric remote spectrometry from space has become in the last 20 years a key component of the Earth monitoring system: their large coverage and deci-kelvin stability have demonstrated their usefulness for weather prediction, atmospheric…

Instrumentation and Detectors · Physics 2021-11-17 Pierre Dussarrat , Bertrand Theodore , Dorothee Coppens , Carsten Standfuss , Bernard Tournier

Accurate extrinsic calibration of multiple LiDARs is crucial for improving the foundational performance of three-dimensional (3D) map reconstruction systems. This paper presents a novel targetless extrinsic calibration framework for…

Robotics · Computer Science 2025-07-15 Han Ye , Yuqiang Jin , Jinyuan Liu , Tao Li , Wen-An Zhang , Minglei Fu

In this paper we develop a new approach to the calibration of polarimetric radar data based on two key ideas. The first is the use of in-scene trihedral corner reflectors not only for radiometric and geometric calibration but also to…

Signal Processing · Electrical Eng. & Systems 2021-11-09 Shane R. Cloude

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

The aim of the new generation of radio synthesis arrays such as LOFAR and SKA is to achieve much higher sensitivity, resolution and frequency coverage than what is available now, especially at low frequencies. To accomplish this goal, the…

Instrumentation and Methods for Astrophysics · Physics 2015-05-20 S. Kazemi , S. Yatawatta , S. Zaroubi , A. G. de Bruyn , L. V. E. Koopmans , J. Noordam

We present an estimate of the Atacama Cosmology Telescope (ACT) detector polarization angle systematic uncertainty from optics perturbation analysis using polarization-sensitive ray tracing in CODE V optical design software. Uncertainties…

A limiting systematic effect in 21-cm interferometric experiments is the chromaticity due to the coupling between the sky and the instrument. This coupling is sourced by the instrument primary beam; therefore it is important to know the…

Instrumentation and Methods for Astrophysics · Physics 2022-06-22 Ainulnabilah Nasirudin , David Prelogovic , Steven G. Murray , Andrei Mesinger , Gianni Bernardi

Radio interferometers are phased arrays producing high-resolution images from the covariance matrix of measurements. Calibration of such instruments is necessary and is a critical task. This is how the estimation of instrumental errors is…

Instrumentation and Methods for Astrophysics · Physics 2023-09-26 Yassine Mhiri , Mohammed Nabil El Korso , Arnaud Breloy , Pascal Larzabal

Aims: To propose a method for the polarimetric calibration of large astronomical mirrors that does not require use of special optical devices nor knowledge of the exact polarization properties of the calibration target. Methods: We study…

Instrumentation and Methods for Astrophysics · Physics 2015-11-11 A. Lopez Ariste

Response calibration is the process of inferring how much the measured data depend on the signal one is interested in. It is essential for any quantitative signal estimation on the basis of the data. Here, we investigate self-calibration…

Instrumentation and Methods for Astrophysics · Physics 2015-06-18 Torsten A. Enßlin , Henrik Junklewitz , Lars Winderling , Maksim Greiner , Marco Selig

Radio Interferometry is an essential method for astronomical observations. Self-calibration techniques have increased the quality of the radio astronomical observations (and hence the science) by orders of magnitude. Recently, there is a…

Astrophysics · Physics 2008-11-03 Sarod Yatawatta , Saleem Zaroubi , Ger de Bruyn , Leon Koopmans , Jan Noordam

Contamination due to foregrounds (Galactic and Extra-galactic), calibration errors and ionospheric effects pose major challenges in detection of the cosmic 21 cm signal in various Epoch of Reionization (EoR) experiments. We present the…

Instrumentation and Methods for Astrophysics · Physics 2018-05-15 B. K. Gehlot , L. V. E. Koopmans , A. G. de Bruyn , S. Zaroubi , M. A. Brentjens , K. M. B. Asad , M. Hatef , V. Jelic , M. Mevius , A. R. Offringa , V. N. Pandey , S. Yatawatta

Radio interferometers can measure the full polarization state of incoming waves by cross--correlating all combinations of two orthogonal polarizations at each antenna. The independent sets of electronics used to detect the two polarization…

Instrumentation and Methods for Astrophysics · Physics 2012-05-18 W. D. Cotton

Our ability to calibrate current kilometer-scale interferometers can potentially confound the inference of astrophysical signals. Current calibration uncertainties are well described by a Gaussian process. I exploit this description to…

Instrumentation and Methods for Astrophysics · Physics 2022-04-27 Reed Essick

Calibration errors in the response function of a gravitational wave detector degrade its ability to detect and then to measure the properties of any detected signals. This paper derives the needed levels of calibration accuracy for each of…

General Relativity and Quantum Cosmology · Physics 2015-05-13 Lee Lindblom
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