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Related papers: Identifying Acoustic Wave Sources on the Sun. II. …

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Understanding the abundance and distribution of fish in tidal energy streams is important to assess risks presented by introducing tidal energy devices to the habitat. However tidal current flows suitable for tidal energy are often highly…

The solar atmosphere is extremely dynamic, and many important phenomena develop on small scales that are unresolved in observations with the Helioseismic and Magnetic Imager (HMI) instrument on the Solar Dynamics Observatory (SDO). For…

Solar and Stellar Astrophysics · Physics 2015-08-06 Irina N. Kitiashvili , Sebastien Couvidat , Andreas Lagg

The analysis of time-sequence satellite images is a powerful tool in remote sensing; it is used to explore the statics and dynamics of the surface of the earth. Usually, the quality of multitemporal images is influenced by metrological…

Image and Video Processing · Electrical Eng. & Systems 2024-05-01 Hessah Albanwan

We present a comparison between the performance of a selection of source finders using a new software tool called Hydra. The companion paper, Paper~I, introduced the Hydra tool and demonstrated its performance using simulated data. Here we…

Stellar seismology reveals some interior properties of thousands of solar-type stars but the solar seismic sound speed stays puzzling since a decade as it disagrees with the Standard Solar Model (SSM) prediction. One of the explanations of…

Solar and Stellar Astrophysics · Physics 2015-09-14 M. Le Pennec , X. Ribeyre , J. -E. Ducret , S. Turck-Chièze

Point Source (PS) detection is an important issue for future Cosmic Microwave Background (CMB) experiments since they are one of the main contaminants to the recovery of CMB signal at small scales. Improving its multifrequency detection…

Instrumentation and Methods for Astrophysics · Physics 2022-02-09 J. M. Casas , J. González-Nuevo , L. Bonavera , D. Herranz , S. L. Suárez Gómez , M. M. Cueli , D. Crespo , J. D. Santos , M. L. Sánchez , F. Sánchez-Lasheras , F. J. de Cos

Localizing sources on the sky is crucial for realizing the full potential of gravitational waves for astronomy, astrophysics, and cosmology. We show that the mid-frequency band, roughly 0.03 to 10 Hz, has significant potential for angular…

General Relativity and Quantum Cosmology · Physics 2018-02-07 Peter W. Graham , Sunghoon Jung

Context. Remote sensing of weak and small-scale solar magnetic fields is of utmost relevance for a number of important open questions in solar physics. This requires the acquisition of spectropolarimetric data with high spatial resolution…

Instrumentation and Methods for Astrophysics · Physics 2016-05-18 F. A. Iglesias , A. Feller , K. Nagaraju , S. K. Solanki

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

Ambient noise measured in the deep ocean is studied in the context of a search for signals from ultra-high energy cosmic ray neutrinos. The spectral shape of the noise at the relevant high frequencies is found to be very stable for an…

Atmospheric and Oceanic Physics · Physics 2010-11-23 Naoko Kurahashi , Giorgio Gratta

The well-observed acoustic halo is an enhancement in time-averaged Doppler velocity and intensity power with respect to quiet-sun values which is prominent for weak and highly inclined field around the penumbra of sunspots and active…

Solar and Stellar Astrophysics · Physics 2016-01-27 Carlos Rijs , S. P. Rajaguru , Damien Przybylski , Hamed Moradi , Paul S. Cally , Sergiy Shelyag

Solar oscillations consist of a rich spectrum of internal acoustic waves and surface gravity waves, stochastically excited by turbulent convection. They have been monitored almost continuously over the last ten years with high-precision…

Astrophysics · Physics 2010-11-26 L. Gizon

The reconstruction of the unknown acoustic source is studied using the noisy multiple frequency data on a remote closed surface. Assume that the unknown source is coded in a spatial dependent piecewise constant function, whose support set…

Numerical Analysis · Mathematics 2019-07-23 Zhiliang Deng , Xiaomei Yang , Jiangfeng Huang

We have observed an area of approximatley 27 deg^2 to an rms noise level of less than 0.2 mJy at 15.7 GHz, using the Arcminute Microkelvin Imager Large Array. These observations constitute the most sensitive radio-source survey of any…

We present observational evidence for the presence of MHD waves in the solar photosphere deduced from SOHO/MDI Dopplergram velocity observations. The magneto-acoustic perturbations are observed as acoustic power enhancement in the sunspot…

Solar and Stellar Astrophysics · Physics 2013-07-10 S. Zharkov , S. Shelyag , V. Fedun , R. Erdélyi , M. J. Thompson

Dynamic wavefront aberrations negatively impact a wide range of optical applications including astronomy, optical free-space telecommunications and bio-imaging. Wavefront errors can be compensated by an adaptive optics system comprised of a…

This paper presents a Bayesian estimation method for the passive localization of an acoustic source in shallow water. Our probabilistic focalization approach estimates the time-varying source location by associating direction of arrival…

Signal Processing · Electrical Eng. & Systems 2021-09-15 Florian Meyer , Kay L. Gemba

Time-distance helioseismology is the method of the study of the propagation of waves through the solar interior via the travel times of those waves. The travel times of wave packets contain information about the conditions in the interior…

Solar and Stellar Astrophysics · Physics 2019-02-20 David Korda , Michal Švanda

A crucial feature not widely accounted for in local helioseismology is that surface magnetic regions actually open a window from the interior into the solar atmosphere, and that the seismic waves leak through this window, reflect high in…

Solar and Stellar Astrophysics · Physics 2015-06-24 H. Moradi , P. S. Cally , D. Przybylski , S. Shelyag

Monitoring remote forests is a global challenge central to climate mitigation and biodiversity conservation, yet satellite observations are frequently limited by weather, dense canopies, and solar dependency. Here we show that passive…