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Related papers: Water Vapour Radiometers for the Australia Telesco…

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Fluctuating properties of the atmosphere, and in particular its water vapour content, give rise to phase fluctuations of astronomical signals which, if uncorrected, lead to rapid deterioration of performance of (sub)-mm interferometers on…

Instrumentation and Methods for Astrophysics · Physics 2015-06-15 Bojan Nikolic , Rosie C. Bolton , Sarah F. Graves , Richard E. Hills , John S. Richer

We report on laboratory test results of the Compact Water Vapor Radiometer (CWVR) prototype for the NSF's Karl G. Jansky Very Large Array (VLA), a five-channel design centered around the 22 GHz water vapor line. Fluctuations in precipitable…

Instrumentation and Methods for Astrophysics · Physics 2019-08-20 Ajay Gill , Robert J. Selina , Bryan J. Butler

We present a millimetre-wave site characterisation for the Australia Telescope Compact Array (ATCA) based on nearly 9 years of data from a seeing monitor operating at this facility. The seeing monitor, which measures the phase fluctuations…

Instrumentation and Methods for Astrophysics · Physics 2015-06-19 Balthasar T. Indermuehle , Michael G. Burton

Path length changes through the atmosphere cause significant errors for astronomical radio interferometry at high frequencies (e.g. 100 GHz). Path length differences typically give rise to a differential excess path of 1mm for antennas…

Astrophysics · Physics 2007-05-23 R. J. Sault , G. J. Carrad , P. J. Hall , J. Crofts

The Atacama Large millimetre/submillimetre Array (ALMA) makes use of water vapour radiometers (WVR), which monitor the atmospheric water vapour line at 183 GHz along the line of sight above each antenna to correct for phase delays…

Instrumentation and Methods for Astrophysics · Physics 2017-09-20 L. T. Maud , R. P. J. Tilanus , T. A. van Kempen , M. R. Hogerheijde , M. Schmalzl , I. Yoon , Y. Contreras , M. C. Toribio , Y. Asaki , W. R. F. Dent , E. Fomalont , S. Matsushita

This memo describes the software engineering and technical details of the design and implementation of the wvrgcal program and associated libraries. This program performs off-line correction of atmospheric phase fluctuations in ALMA…

Instrumentation and Methods for Astrophysics · Physics 2012-07-26 Bojan Nikolic , Sarah F. Graves , Rosie C. Bolton , John S. Richer

The ngVLA has adopted a standalone system with a $\sim$~1.5 m diameter antenna and associated ambient temperature receiver and electronics at each antenna as its baseline design for water vapor radiometer (WVR). The WVR is intended to…

Instrumentation and Methods for Astrophysics · Physics 2026-02-24 Tirupati Kumara Sridharan , Robert Lehmensiek , Yoshiharu Asaki

The ALMA observatory is now putting more focus on high-frequency observations (frequencies from 275-950 GHz). However, high-frequency observations often suffer from rapid variations in atmospheric opacity that directly affect the system…

Instrumentation and Methods for Astrophysics · Physics 2022-12-28 Hao He , William R. F. Dent , Christine Wilson

Atacama Large Millimeter/submillimeter Array (ALMA) will be the world largest mm/submm interferometer, and currently the Early Science is ongoing, together with the commissioning and science verification (CSV). Here we present a study of…

Instrumentation and Methods for Astrophysics · Physics 2015-06-11 S. Matsushita , K. -I. Morita , D. Barkats , R. E. Hills , E. Fomalont , B. Nikolic

The Large Binocular Telescope Interferometer uses a near-infrared camera to measure the optical path length variations between the two AO-corrected apertures and provide high-angular resolution observations for all its science channels…

Instrumentation and Methods for Astrophysics · Physics 2016-12-14 D. Defrère , P. Hinz , E. Downey , M. Böhm , W. C. Danchi , O. Durney , S. Ertel , J. M. Hill , W. F. Hoffmann , B. Mennesson , R. Millan-Gabet , M. Montoya , J. -U. Pott , A. Skemer , E. Spalding , J. Stone , A. Vaz

This paper describes the accuracy and the errors of water vapour content measurements in the atmosphere using optical methods, especially starphotometer. After the general explanations of the used expressions for the star-magnitude…

Atmospheric and Oceanic Physics · Physics 2010-10-19 V. D. Galkin , U. Leiterer , G. A. Alekseeva , V. V. Novikov , V. P. Pakhomov

In a radio interferometer, the determination of geometrical antenna positions relies on accurate calibration of the dry and wet delay of the atmosphere above each antenna. For the Atacama Large Millimeter/Submillimeter Array (ALMA), which…

Instrumentation and Methods for Astrophysics · Physics 2016-10-14 Todd R. Hunter , Robert Lucas , Dominique Broguiere , Ed B. Fomalont , William R. F. Dent , Neil Phillips , David Rabanus , Catherine Vlahakis

This study presents the development and validation of a compact device for measuring the water attenuation length (WAL), utilizing photomultiplier tubes (PMTs), optical fibers, and light-emitting diodes (LEDs). An 8 m water tank and the…

Instrumentation and Detectors · Physics 2025-11-03 Junyou Chen , Jilei Xu , Yongbo Huang , Sibo Wang , Chuanshi Dong , Haoqi Lu , Changgen Yang , Yongpeng Zhang , Yi Wang

We present a Bayesian approach to calculating the coefficients that convert the outputs of ALMA 183 GHz water-vapour radiometers into estimates of path fluctuations which can then be used to correct the observed interferometric…

Instrumentation and Methods for Astrophysics · Physics 2009-03-19 B. Nikolic

Phase noise caused by an inhomogeneous, time-variable water vapor distribution in our atmosphere reduces the angular resolution, visibility amplitude and coherence time of millimeter and submillimeter wavelength interferometers. We present…

Astrophysics · Physics 2009-11-10 James B. Battat , Raymond Blundell , James M. Moran , Scott Paine

We report the use of the Australia Telescope Compact Array (ATCA) to conduct polarimetric observations of the sky at 5 GHz. The ATCA is normally operated as an interferometer array, but these observations were conducted in a split array…

Astrophysics · Physics 2010-11-11 D. McConnell , E. Carretti , R. Subrahmanyan

We demonstrate phase correction of 3 mm VLBI observations using the scanning 18 GHz to 26 GHz water vapour radiometer at Effelsberg and we demonstrate an absolute accuracy of 15 mm in zenith path delay by comparing with GPS and radiosondes.…

Astrophysics · Physics 2007-05-23 A. L. Roy , H. Rottmann , U. Teuber , R. Keller

We present the phase characteristics study of the Atacama Large Millimeter/submillimeter Array (ALMA) long (up to 3 km) baseline, which is the longest baseline tested so far using ALMA. The data consist of long time-scale (10 - 20 minutes)…

Instrumentation and Methods for Astrophysics · Physics 2015-06-23 Satoki Matsushita , Yoshiharu Asaki , Ryohei Kawabe , Ed Fomalont , Denis Barkats , Stuartt Corder

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

Time series both of microwave radiometer brightness temperature measurements at 23.8 and 31.4 GHz and of retrievals of water vapor and liquid water path from these brightness temperatures are evaluated using the detrended fluctuation…

Atmospheric and Oceanic Physics · Physics 2009-11-07 K. Ivanova , E. E. Clothiaux , H. N. Shirer , T. P. Ackerman , J. C. Liljegren , M. Ausloos
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