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Accurate flux density calibration is essential for precise analysis and interpretation of observations across different observation modes and instruments. In this research, we firstly introduce the flux calibration model incorporated in…

Instrumentation and Methods for Astrophysics · Physics 2024-09-04 Ziming Liu , Jie Wang , Yingjie Jing , Zhi-Yu Zhang , Chen Xu , Tiantian Liang , Qingze Chen , Ningyu Tang , Qingliang Yang

The paper aims to emphasise how switched systems can be analysed with elementary techniques which require only undergraduate-level linear algebra and differential equations. It is also emphasised how math software can become useful for…

Computational Engineering, Finance, and Science · Computer Science 2018-08-09 S. Kadyrov , P. S. Skrzypacz , Y. L. Familiant

We present results from the first intensive monitoring campaign of a sample of Compact Symmetric Objects (CSOs). We observed seven CSOs at 8.5 GHz over a period of eight months, with an average spacing between observations of 2.7 days. Our…

Astrophysics · Physics 2009-11-06 C. D. Fassnacht , G. B. Taylor

The absolute frequency of the $^{87}{\rm Sr}$ clock transition measured in 2015 was reevaluated using an improved frequency link to the SI second. The scale interval of International Atomic Time (TAI) that we used as the reference was…

Atomic Physics · Physics 2017-02-01 Hidekazu Hachisu , Gérard Petit , Tetsuya Ido

This paper investigates the effects of setting the sampling frequency significantly higher than conventional guidelines in system identification. Although continuous-time identification methods resolve the numerical difficulties encountered…

Systems and Control · Electrical Eng. & Systems 2025-06-05 Ichiro Maruta , Toshiharu Sugie

The development of sensitive large format imaging arrays for the infrared promises to provide revolutionary capabilities for space astronomy. For example, the Infrared Array Camera (IRAC) on SIRTF will use four 256 x 256 arrays to provide…

Astrophysics · Physics 2016-08-30 D. J. Fixsen , S. H. Moseley , R. G. Arendt

We report on a theoretical analysis of the phase-shift in compact atomic clocks working either with cold or thermal atoms. It is well known that in a microwave cavity with electromagnetic losses, a traveling wave adds to the standing wave…

Atomic Physics · Physics 2017-05-04 Aldo Godone , Salvatore Micalizio

This paper provides an overview of the PACS photometer flux calibration concept, in particular for the principal observation mode, the scan map. The absolute flux calibration is tied to the photospheric models of five fiducial stellar…

The jamming transition of particles with finite-range interactions is characterized by a variety of critical phenomena, including power law distributions of marginal contacts. We numerically study a recently proposed simple model of…

Statistical Mechanics · Physics 2016-01-20 Yoav Kallus

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…

Quantum Physics · Physics 2008-08-22 Jiří Minář , Hugues de Riedmatten , Christoph Simon , Hugo Zbinden , Nicolas Gisin

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 have investigated instability of a superconducting quantum computer by continuously monitoring the qubit output. We found that qubits exhibit a step-like change in the error rates. This change is repeatedly observed, and each step…

Quantum Physics · Physics 2024-03-15 Yuta Hirasaki , Shunsuke Daimon , Toshinari Itoko , Naoki Kanazawa , Eiji Saitoh

Using matter-wave interference, we have investigated thermal phase fluctuations in narrow coplanar, concentric rings of ultracold fermionic superfluids. We found that the correlation length decreases with number density, consistent with…

Quantum Gases · Physics 2024-07-08 Parth Sabharwal , Daniel G. Allman , Pradipta Debnath , Kevin C. Wright

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…

Advanced millimeter-wave software-defined array (SDA) platforms, or testbeds at affordable costs and high performance are essential for the wireless community. In this paper, we present a low-cost, portable, and programmable SDA that allows…

Systems and Control · Electrical Eng. & Systems 2024-09-19 Ashwini Pondeycherry Ganesh , Anthony Perre , Alphan Sahin , Ismail Guvenc , Brian A. Floyd

The relative root mean squared errors (RMSE) of nonparametric methods for spectral estimation is compared for microwave scattering data of plasma fluctuations. These methods reduce the variance of the periodogram estimate by averaging the…

Applications · Statistics 2019-11-15 Kurt S. Riedel , Alexander Sidorenko , David J. Thomson

Solar radio emission, especially at metre-wavelengths, is well known to vary over small spectral ($\lesssim$100\,kHz) and temporal ($<1$\,s) spans. It is comparatively recently, with the advent of a new generation of instruments, that it…

Instrumentation and Methods for Astrophysics · Physics 2019-05-01 Surajit Mondal , Atul Mohan , Divya Oberoi , John S. Morgan , Leonid Benkevitch , Colin J. Lonsdale , Meagan Crowley , Iver H. Cairns

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…

Phase aberrations, despite degrading ultrasound images, also encode valuable information about the spatial distribution of the speed of sound in tissue. In pulse-echo ultrasound, we can quantify them by exploiting speckle correlations.…

Medical Physics · Physics 2025-11-20 Naiara Korta Martiartu , Michael Jaeger

Calibration of radio interferometric observations becomes increasingly difficult towards lower frequencies. Below ~300 MHz, spatially variant refractions and propagation delays of radio waves traveling through the ionosphere cause phase…

Instrumentation and Methods for Astrophysics · Physics 2015-05-13 H. T. Intema , S. van der Tol , W. D. Cotton , A. S. Cohen , I. M. van Bemmel , H. J. A. Rottgering
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