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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…

We introduce a method for detecting astrophysical transients evolving on timescales of milliseconds to minutes using cosmic microwave background (CMB) survey telescopes. While previous transient searches in CMB data operate in map space,…

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)…

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

The temporal behaviour of segmentation clock oscillations show phase synchrony via mean field like coupling of delta protein restricting to nearest neighbours only, in a configuration of cells arranged in a regular three dimensional array.…

Photometric instruments operating at far infrared to millimetre wavelengths often have broad spectral passbands (central wavelength/bandwidth ~ 3 or less), especially those operating in space. A broad passband can result in significant…

Computer model calibration is a crucial step in building a reliable computer model. In the face of massive physical observations, a fast estimation for the calibration parameters is urgently needed. To alleviate the computational burden, we…

Statistics Theory · Mathematics 2022-11-24 Shurui Lv , Yan Wang , Jun Yu

We have observed damped longitudinal cosmological-scale oscillations in a unique model-independent plot of scale factor against cosmological time for Type Ia supernovae data. We found several first-derivative relative maxima/minima spanning…

Cosmology and Nongalactic Astrophysics · Physics 2019-06-17 H. I. Ringermacher , L. R. Mead

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

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…

Instrumentation and Methods for Astrophysics · Physics 2011-01-25 I. Marti-Vidal , J. C. Guirado , S. Jimenez-Monferrer , J. M. Marcaide

The problem of measuring a time-varying phase, even when the statistics of the variation is known, is considerably harder than that of measuring a constant phase. In particular, the usual bounds on accuracy - such as the $1/(4\bar{n})$…

Quantum Physics · Physics 2018-05-01 Kiarn T. Laverick , Howard M. Wiseman , Hossien T. Dinani , Dominic W. Berry

Atmospheric remote spectrometry from space has become in the last 20 years a key component of the Earth monitoring system: their large coverage and deci-kelvin stability have demonstrated their usefulness for weather prediction, atmospheric…

Instrumentation and Detectors · Physics 2021-11-17 Pierre Dussarrat , Bertrand Theodore , Dorothee Coppens , Carsten Standfuss , Bernard Tournier

This paper addresses the challenges of wideband signal beamforming in radar systems and proposes a new calibration method. Due to operating conditions, the frequency dependent characteristics of the system can be changed, and amplitude,…

Signal Processing · Electrical Eng. & Systems 2023-06-27 Hyung-Woo Kim , Jin-woo Kim , Jin-ha Kim , JaeYoung Choi , Sangpyo Hong , Byungkwan Kim

This manual is intended to help ALMA and other interferometer users improve images by recognising limitations and how to overcome them and deciding when and how to use self-calibration. The images provided by the ALMA Science Archive are…

Instrumentation and Methods for Astrophysics · Physics 2022-07-13 A. M. S. Richards , E. Moravec , S. Etoka , E. B. Fomalont , A. F. Pérez-Sánchez , M. C. Toribio , R. A. Laing

Though there has been a significant amount of work investigating the early stages of low-mass star formation in recent years, the evolution of the mass assembly rate onto the central protostar remains largely unconstrained. Examining in…

We have previously [Phys. Rev. A 65, 043803 (2002)] analyzed adaptive measurements for estimating the continuously varying phase of a coherent beam, and a broadband squeezed beam. A real squeezed beam must have finite photon flux N and…

Quantum Physics · Physics 2007-05-23 Dominic W. Berry , Howard M. Wiseman

We have implemented control and data-taking software that makes it possible to scan the beams of individual ALMA antennas to perform quite complex patterns while recording the signals at high rates. We conducted test observations of the Sun…

Instrumentation and Methods for Astrophysics · Physics 2015-02-24 Neil Phillips , Richard Hills , Tim Bastian , Hugh Hudson , Ralph Marson , Sven Wedemeyer

Fluctuations of solar wind magnetic field and plasma parameters exhibit a typical turbulence power spectrum with a spectral index ranging between $\sim -5/3$ and $\sim -3/2$. In particular, at $1$ AU, the magnetic field spectrum, observed…

Space Physics · Physics 2019-07-10 R. Bruno , D. Telloni , L. Sorriso-Valvo , R. Marino , R. De Marco , R. DAmicis

Understanding the temporal characteristics of data from low frequency radio telescopes is of importance in devising suitable calibration strategies. Application of time series analysis techniques to data from radio telescopes can reveal a…

Instrumentation and Methods for Astrophysics · Physics 2023-02-20 Jishnu N. Thekkeppattu , Cathryn M. Trott , Benjamin McKinley

Solar flares are known to release a large amount of energy into accelerating electrons. Studying small timescale ($\leq$ 2s) fluctuations in nonthermal X-ray flux offers the opportunity to probe the nature of those acceleration mechanisms.…

Solar and Stellar Astrophysics · Physics 2020-11-11 Trevor Knuth , Lindsay Glesener