Related papers: Characterization of Instrumental Phase Stability
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…
For the submillimeter band observations, we have been routinely adopting the calibration cycle time of 20-30 minutes, which is the same as any typical centimeter and millimeter band observations. This cycle time, largely corrects only the…
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…
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…
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…
The Submillimeter Array (SMA), a collaboration between the Smithsonian Astrophysical Observatory and the Academica Sinica Institute for Astronomy and Astrophysics of Taiwan, is an eight-element radio-interferometer designed to operate…
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)…
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…
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…
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 report a new experimental approach for observing mesoscopic fluctuations underlying the thermodynamic anomalies of ambient liquid water. In this approach, two sound velocity measurements with different frequencies, namely inelastic X-ray…
Precision phase readout of optical beat note signals is one of the core techniques required for intersatellite laser interferometry. Future space based gravitational wave detectors like eLISA require such a readout over a wide range of MHz…
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…
Interferometric wavelength meters have attained frequency resolutions down to the MHz range. In particular, Fizeau interferometers, which have no moving parts, are becoming a popular tool for laser characterization and stabilization. In…
Many protocols for long distance quantum communication require interferometric phase stability over long distances of optical fibers. In this paper we investigate the phase noise in long optical fibers both in laboratory environment and in…
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…
The Naval Research Laboratory and the National Radio Astronomy Observatory completed implementation of a low frequency capability on the VLA at 73.8 MHz in 1998. This frequency band offers unprecedented sensitivity (~25 mJy/beam) and…
We present a computer-based active interferometer stabilization method that can be set to an arbitrary phase difference and does not rely on modulation of the interfering beams. The scheme utilizes two orthogonal modes propagating through…
Phase referencing is a standard calibration procedure in radio interferometry. It allows to detect weak sources by using quasi-simultaneous observations of closeby sources acting as calibrators. Therefore, it is assumed that, for each…
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…