中文
相关论文

相关论文: Correcting the Polarization Leakage Phases and Amp…

200 篇论文

Mechanical and electronic imperfections can result into polarization leakage in individual antennas of a radio interferometer. Such leakages manifest themselves as closure errors even in co-polar visibility measurements of unpolarized…

天体物理学 · 物理学 2009-11-06 Sanjay Bhatnagar , Rajaram Nityananda

Leakage of diffuse polarized emission into Stokes I caused by the polarized primary beam of the instrument might mimic the spectral structure of the 21-cm signal coming from the epoch of reionization (EoR) making their separation difficult.…

By measuring photoelectron tracks, the gas pixel detectors of the Imaging X-ray Polarimetry Explorer satellite provide estimates of the photon detection location and its electric vector position angle (EVPA). However, imperfections in…

天体物理仪器与方法 · 物理学 2024-09-24 Jack T. Dinsmore , Roger W. Romani

Next generation radio telescope arrays are being designed and commissioned to accurately measure polarized intensity and rotation measures across the entire sky through deep, wide-field radio interferometric surveys. Radio interferometer…

天体物理仪器与方法 · 物理学 2017-08-02 P. Jagannathan , S. Bhatnagar , U. Rau , A. R. Taylor

A critical challenge in the observation of the redshifted 21-cm line is its separation from bright Galactic and extragalactic foregrounds. In particular, the instrumental leakage of polarized foregrounds, which undergo significant Faraday…

宇宙学与河外天体物理 · 物理学 2017-10-18 C. D. Nunhokee , G. Bernardi , S. A. Kohn , J. E. Aguirre , N. Thyagarajan , J. S. Dillon , G. Foster , T. L. Grobler , J. Z. E. Martinot , A. R. Parsons

In laser gravitational waves detectors optical loss restricts sensitivity. We discuss polarization scattering as one more possible mechanism of optical losses. Circulated inside interferometer light is polarized and after reflection its…

天体物理仪器与方法 · 物理学 2020-02-20 Sergey P. Vyatchanin

Taking advantage of the advances in array detector technology, an imaging polarimeter (IMPOL) has been constructed for measuring linear polarization in the wavelength band from 400-800 nm. It makes use of a Wollaston prism as the analyser…

天体物理学 · 物理学 2009-09-15 A. N. Ramaprakash , Ranjan Gupta , A. K. Sen , S. N. Tandon

Current mm/submm interferometers, like the Atacama Large mm/submm Array (ALMA), use receivers that register the sky signal in a linear polarization basis. In the case of observations performed in full-polarization mode (where the…

天体物理仪器与方法 · 物理学 2016-09-21 I. Marti-Vidal , W. H. T. Vlemmings , S. Muller

Polarization leakage of foreground synchrotron emission is a critical issue in HI intensity mapping experiments. While the sought-after HI emission is unpolarized, polarized foregrounds such as Galactic and extragalactic synchrotron…

天体物理仪器与方法 · 物理学 2016-12-28 Yu-Wei Liao , Tzu-Ching Chang , Cheng-Yu Kuo , Kiyoshi Wesley Masui , Niels Oppermann , Ue-Li Pen , Jeffrey B. Peterson

Modern dual-polarization receivers allow a radio telescope to characterize the full polarization state of incoming insterstellar radio waves. Many astronomers incorrectly consider a polarimeter to be the "backend" of the telescope. We go to…

天体物理仪器与方法 · 物理学 2021-10-13 Timothy Robishaw , Carl Heiles

Imaging both the polarization and the wavefront of a light beam is a complex task that typically demands several intensity acquisitions. Furthermore, sequential acquisition solutions are incompatible with the monitoring of ultra-fast…

光学 · 物理学 2024-07-30 Baptiste Blochet , Grégoire Lelu , Miguel A. Alonso , Marc Guillon

Measurement of cosmic microwave background polarization is today a major goal of observational cosmology. The level of the signal to measure, however, makes it very sensitive to various systematic effects. In the case of Planck, which…

In-line polarimeters perform non-destructive polarization measurements of optical signals, and play a critical role in monitoring and controlling the polarization environment in for example optical networks. While current in-line…

光学 · 物理学 2015-12-10 J. P. Balthasar Müller , Kristjan Leosson , Federico Capasso

We present an imaging algorithm for polarimetric interferometric data from radio telescopes. It is based on Bayesian statistics and thereby able to provide uncertainties and to incorporate prior information such as positivity of the total…

天体物理仪器与方法 · 物理学 2025-04-02 Philipp Arras , Jakob Roth , Martin Reinecke , Richard A. Perley , Andrei Frolov , Rüdiger Westermann , Torsten A. Enßlin

X-ray polarimetry, based on Gas Pixel Detectors (GPDs), have reached a high level of maturity with the Imaging X-ray Polarimeter Explorer (IXPE) leading to the first ever spatially resolved polarimetric measures. However, being this a new…

天体物理仪器与方法 · 物理学 2023-04-05 N. Bucciantini , N. Di Lalla , R. W. R. Romani , S. Silvestri , M. Negro , L. Baldini , A. F. Tennant , A. Manfreda

The polarization analysis of the light is typically carried out using modulation schemes. The light of unknown polarization state is passed through a set of known modulation optics and a detector is used to measure the total intensity…

天体物理学 · 物理学 2008-05-01 A. Asensio Ramos , M. Collados

The process of wide-field synthesis imaging is explored, with the aim of understanding the implications of variable, polarised primary beams for forthcoming Epoch of Reionisation experiments. These experiments seek to detect weak signatures…

天体物理仪器与方法 · 物理学 2012-06-05 Daniel A. Mitchell , Randall B. Wayth , Gianni Bernardi , Lincoln J. Greenhill , Stephen M. Ord

Electrode polarization error is the biggest problem when measuring the low frequency dielectric properties of electrolytes or suspensions of particles, including cells, in electrolytes. We present a simple and robust method to remove the…

软凝聚态物质 · 物理学 2008-05-13 Camelia Prodan , Corina Bot

There are investigated amplitude-phase method of the moving object bearing when there are used orthogonal linear polarized radio signals illuminated simultaneously from two horizontally spaced points with known co-ordinates. The bearing is…

信号处理 · 电气工程与系统科学 2020-12-24 V L Gulko , A A Mescheryakov

An approach for measuring linear X-ray polarization over a broad-band using conventional spectroscopic optics is described. A set of multilayer-coated flats reflect the dispersed X-rays to the instrument detectors. The intensity variation…

天体物理学 · 物理学 2009-11-13 Herman L. Marshall
‹ 上一页 1 2 3 10 下一页 ›