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Solar prominences contain a significant amount of neutral species. The dynamics of the ionised and neutral fluids composing the prominence plasma can be slightly different if the collisional coupling is not strong enough. Large-scale…

Solar and Stellar Astrophysics · Physics 2023-11-07 S. J. González Manrique , E. Khomenko , M. Collados , C. Kuckein , T. Felipe , P. Gömöry

This paper considers the problem of low-dimensional visualisation of very high dimensional information sources for the purpose of situation awareness in the maritime environment. In response to the requirement for human decision support…

Computational Engineering, Finance, and Science · Computer Science 2014-02-27 Iain Rice , Roger Benton , Les Hart , David Lowe

Two sequences of solar images obtained by the Transition Region and Coronal Explorer in three UV passbands are studied using wavelet and Fourier analysis and compared to the photospheric magnetic flux measured by the Michelson Doppler…

Many ecological studies and conservation policies are based on field observations of species, which can be affected by systematic variability introduced by the observation process. A recently introduced causal modeling technique called…

Methodology · Statistics 2021-01-05 Shiv Shankar , Daniel Sheldon , Tao Sun , John Pickering , Thomas G. Dietterich

In the civilian aviation field, the radar detection of hazardous weather phenomena (winds) is very important. This detection will allow the avoidance of these phenomena and consequently will enhance the safety of flights. In this work, we…

Instrumentation and Detectors · Physics 2012-01-27 Mohand Lagha , Mohamed Tikhemirine , Said Bergheul , Tahar Rezoug , Maamar Bettayeb

Waves can be used to probe and image an unknown medium. Passive imaging uses ambient noise sources to illuminate the medium. This paper considers passive imaging with moving sensors. The motivation is to generate large synthetic apertures,…

Classical Physics · Physics 2017-02-15 Mathias Fink , Josselin Garnier

Regular spaceborne measurements have revealed that solar brightness varies on multiple timescales, variations on timescales greater than a day being attributed to surface magnetic field. Independently, ground-based and spaceborne…

Solar and Stellar Astrophysics · Physics 2016-04-27 A. I. Shapiro , S. K. Solanki , N. A. Krivova , K. L. Yeo , W. K. Schmutz

A trade-off between speed and information controls our understanding of astronomical objects. Fast-to-acquire photometric observations provide global properties, while costly and time-consuming spectroscopic measurements enable a better…

Instrumentation and Methods for Astrophysics · Physics 2022-11-11 Lars Doorenbos , Stefano Cavuoti , Giuseppe Longo , Massimo Brescia , Raphael Sznitman , Pablo Márquez-Neila

Prediction of the Solar Energetic Particle (SEP) events garner increasing interest as space missions extend beyond Earth's protective magnetosphere. These events, which are, in most cases, products of magnetic reconnection-driven processes…

Solar convection is visible as a net blueshift of absorption lines, which becomes apparent when observing quiet Sun granulation. This blueshift exhibits variations from the disc centre to the solar limb due to differing projection angles…

Solar and Stellar Astrophysics · Physics 2023-12-13 M. Ellwarth , B. Ehmann , S. Schäfer , A. Reiners

Gravitational waves imprint apparent Doppler shifts on the frequency of photons propagating between an emitter and detector of light. This forms the basis of a method to detect gravitational waves using Doppler velocimetry between pairs of…

Atomic Physics · Physics 2015-06-25 Amar C. Vutha

We present a new method that combines the results of an oscillation study made in optical and radio observations. The optical spectral measurements in photospheric and chromospheric lines of the line-of-sight velocity were carried out at…

Solar and Stellar Astrophysics · Physics 2015-03-18 V. E. Abramov-Maximov , G. B. Gelfreikh , N. I. Kobanov , K. Shibasaki , S. A. Chupin

With the increasing quality of asteroseismic observations it is important to minimize the random and systematic errors in mode parameter estimates. To this end it is important to understand how the oscillations relate to the directly…

Solar and Stellar Astrophysics · Physics 2015-06-17 Jesper Schou

We establish a quantitative relationship between photometric and spectroscopic detections of solar-like oscillations using ab initio, three-dimensional (3D), hydrodynamical numerical simulations of stellar atmospheres. We present a…

Solar and Stellar Astrophysics · Physics 2021-02-17 Yixiao Zhou , Thomas Nordlander , Luca Casagrande , Meridith Joyce , Yaguang Li , Anish M. Amarsi , Henrique Reggiani , Martin Asplund

The development of space-borne missions has significantly improved the quality of the measured spectra of solar-like oscillators. Their $p$-mode line profiles can now be resolved, and the asymmetries inferred for a variety of stars other…

Solar and Stellar Astrophysics · Physics 2021-01-04 J. Philidet , K. Belkacem , H. -G. Ludwig , R. Samadi , C. Barban

It is challenging to detect small-floating object in the sea clutter for a surface radar. In this paper, we have observed that the backscatters from the target brake the continuity of the underlying motion of the sea surface in the…

Signal Processing · Electrical Eng. & Systems 2020-09-10 Yi Zhou , Yin Cui , Xiaoke Xu , Jidong Suo , Xiaoming Liu

Doppler lensing is the apparent change in object size and magnitude due to peculiar velocities. Objects falling into an overdensity appear larger on its near side, and smaller on its far side, than typical objects at the same redshifts.…

Cosmology and Nongalactic Astrophysics · Physics 2014-12-03 David J. Bacon , Sambatra Andrianomena , Chris Clarkson , Krzysztof Bolejko , Roy Maartens

The radial velocity (RV) is a basic physical quantity which can be determined through Doppler shift of the spectrum of a star. The precision of RV measurement depends on the resolution of the spectrum we used and the accuracy of wavelength…

We investigate the effect of localized opacity modifications on the sound-speed profile of solar models. The sound-speed difference between the Sun and a solar model is used to deduce the opacity correction that would be required to bring…

Astrophysics · Physics 2008-02-03 S. C. Tripathy , Sarbani Basu , J. Christensen-Dalsgaard

High-resolution observations of dynamic phenomena give insight into properties and processes that govern the low solar atmosphere. We present the analysis of jet-like phenomena emanating from a penumbral foot-point in active region (AR)…

Solar and Stellar Astrophysics · Physics 2020-10-09 Llŷr Dafydd Humphries , Erwin Verwichte , David Kuridze , Huw Morgan
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