Related papers: Phase Correction for ALMA with 183 GHz Water Vapou…

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…

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…

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)…

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)…

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…

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…

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…

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…

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…

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…

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…

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…

Atmospheric water vapor causes significant undesired phase fluctuations for the Submillimeter Array (SMA) interferometer, particularly in its highest frequency observing band of 690 GHz. One proposed solution to this atmospheric effect is…

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…

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…

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…

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…

The success of any ALMA phase-calibration strategy, which incorporates phase transfer, depends on a good understanding of how the atmospheric path delay changes with frequency (e.g. Holdaway & Pardo 2001). We explore how the wet dispersive…

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…

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…