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Related papers: Phase correction for ALMA - Investigating water va…

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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

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

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

This paper presents the first detailed investigation of the characteristics of mm/submm phase fluctuation and phase correction methods obtained using ALMA with baseline lengths up to ~15 km. Most of the spatial structure functions (SSFs)…

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 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 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

We present a long-term overview of the atmospheric phase stability at the Atacama Large Millimeter/submillimeter Array (ALMA) site, using >5 years of data, that acts as the successor to the studies summarized two decades ago by Evans et al…

Instrumentation and Methods for Astrophysics · Physics 2023-04-18 Luke T. Maud , Andrés F. Pérez-Sánchez , Yoshiharu Asaki , Felix Stoehr , Bill Dent , María Díaz Trigo

We have developed Water Vapour Radiometers (WVRs) for the Australia Telescope Compact Array (ATCA) that are capable of determining signal path length fluctuations by virtue of measuring small temperature fluctuations in the atmosphere using…

Instrumentation and Methods for Astrophysics · Physics 2015-06-12 Balthasar T. Indermuehle , Michael G. Burton , Jonathan Crofts

The Atacama Millimeter/submillimeter Array (ALMA) Phasing Project (APP) has developed and deployed the hardware and software necessary to coherently sum the signals of individual ALMA antennas and record the aggregate sum in Very Long…

By observing bright and compact astronomical sources while also taking data with the 183 GHz Water Vapour Radiometers, ALMA will be able to measure the `empirical' relationship between fluctuations in the phase of the astronomical signal…

Instrumentation and Methods for Astrophysics · Physics 2009-07-28 Bojan Nikolic

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

We conducted the observational tests of a phase correction scheme for the Atacama Compact Array (ACA) of the Atacama Large Millimeter and submillimeter Array (ALMA) using the Submillimeter Array (SMA). Interferometers at millimeter- and…

Instrumentation and Methods for Astrophysics · Physics 2015-05-19 Satoki Matsushita , Yu-Lin Chen

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

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 present a detailed description of the special procedures for calibration and quality assurance of Atacama Large Millimeter/submillimeter Array (ALMA) observations in Very Long Baseline Interferometry (VLBI) mode. These procedures are…

Further analysis has been made on the millimeter and submillimeter-wave (100-1600 GHz or 3 mm - 188 micron) atmospheric opacity data taken with the Fourier Transform Spectrometer (FTS) at Pampa la Bola, 4800 m above sea level in northern…

Astrophysics · Physics 2015-06-24 Satoki Matsushita , Hiroshi Matsuo

A diverse array of science goals require accurate flux calibration of observations with the Atacama Large Millimeter/Submillimeter array (ALMA), however, this goal remains challenging due to the stochastic time-variability of the ``grid''…

Instrumentation and Methods for Astrophysics · Physics 2020-11-25 Logan Francis , Doug Johnstone , Gregory Herczeg , Todd R. Hunter , Daniel Harsono

An international consortium is presently constructing a beamformer for the Atacama Large Millimeter/submillimeter Array (ALMA) in Chile that will be available as a facility instrument. The beamformer will aggregate the entire collecting…

We report a quantitative evaluation of weak-value amplification (WVA) for longitudinal phase measurements using Allan variance analysis. Building on a recent double-slit interferometry experiment with real weak values [Phys. Rev. Lett. 134,…

Quantum Physics · Physics 2026-03-25 Jing-Hui Huang , Xiang-Yun Hu
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