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In this paper, a multistatic Doppler sensing system is proposed for the drone tracking via downlink Long-Term Evolution (LTE) signals. Specifically, the LTE base stations (BSs) are exploited as signal illuminators, and three passive sensing…

Signal Processing · Electrical Eng. & Systems 2025-10-01 Chenqing Ji , Qionghui Liu , Jiahong Liu , Chao Yu , Yifei Sun , Rui Wang , Fan Liu

Observations of small-scale brightenings in the low solar atmosphere can provide valuable constraints on possible heating/heat-transport mechanisms. We present a method for the detection and analysis of brightenings and demonstrate its…

Solar and Stellar Astrophysics · Physics 2021-07-30 Llŷr Dafydd Humphries , Huw Morgan , David Kuridze

In this paper, we study a new intelligent refracting surface (IRS)-assisted high-mobility communication with the IRS deployed in a high-speed moving vehicle to assist its passenger's communication with a static base station (BS) on the…

Information Theory · Computer Science 2021-03-10 Zixuan Huang , Beixiong Zheng , Rui Zhang

Standing slow mode waves in hot flaring loops are exclusively observed in spectrometers and are used to diagnose the magnetic field strength and temperature of the loop structure. Due to the lack of spatial information, the longitudinal…

Solar and Stellar Astrophysics · Physics 2015-07-15 D. Yuan , T. Van Doorsselaere , D. Banerjee , P. Antolin

Alfv\'enic waves have gained renewed interest since the existence of ubiquitous propagating kink waves were discovered in the corona. {It has long been suggested that Alfv\'enic} waves play an important role in coronal heating and the…

Solar and Stellar Astrophysics · Physics 2019-05-15 Ajay K. Tiwari , Richard J. Morton , Stephane Régnier , James A. McLaughlin

The Helioseismic and Magnetic Imager (HMI) and the Atmospheric Imaging Assembly (AIA) instruments onboard the Solar Dynamics Observatory satellite produce Doppler velocity and continuum intensity at 6173 A as well as intensity maps at 1600…

Solar and Stellar Astrophysics · Physics 2015-06-17 Sebastien Couvidat

The method of measurement of Doppler frequency shift of ionospheric signal - HF Doppler technique - is one of well-known and widely used methods of ionosphere research. It allows to research various disturbances in the ionosphere. There are…

Geophysics · Physics 2014-10-15 Inna R. Petrova , Vladimir V. Bochkarev , Ruslan R. Latypov

Quasi-periodic intensity disturbances propagating upward along the coronal structure have been extensively studied using EUV imaging observations from SOHO/EIT and TRACE. They were interpreted as either slow mode magnetoacoustic waves or…

Solar and Stellar Astrophysics · Physics 2012-01-26 Tongjiang Wang , Leon Ofman , Joseph M. Davila

Convective motions in the solar atmosphere cause spectral lines to become asymmetric and shifted in wavelength. For photospheric lines, this differential Doppler shift varies from the solar disk center to the limb. Precise and comprehensive…

Solar and Stellar Astrophysics · Physics 2019-04-10 Johannes Löhner-Böttcher , Wolfgang Schmidt , Rolf Schlichenmaier , Tilo Steinmetz , Ronald Holzwarth

We use G-band and Ca II H image sequences from the Dutch Open Telescope (DOT) to study magnetic elements that appear as bright points in internetwork parts of the quiet solar photosphere and chromosphere. We find that many of these bright…

Astrophysics · Physics 2008-11-26 A. G. de Wijn , R. J. Rutten , E. M. W. P. Haverkamp , P. Sütterlin

The sub-arcsec bright points (BP) associated with the small scale magnetic fields in the lower solar atmosphere are advected by the evolution of the photospheric granules. We measure various quantities related to the horizontal motions of…

Solar and Stellar Astrophysics · Physics 2012-05-28 LP. Chitta , A. A. van Ballegooijen , L. Rouppe van der Voort , E. E. DeLuca , R. Kariyappa

We use UV spectral observations of active regions with the Interface Region Imaging Spectrograph (IRIS) to investigate the properties of the coronal FeXII 1349.4A emission at unprecedented high spatial resolution (~0.33"). We find that by…

Solar and Stellar Astrophysics · Physics 2016-08-17 Paola Testa , Bart De Pontieu , Viggo Hansteen

The origin of the slow solar wind is still an open issue. It has been suggested that upflows at the edge of active regions (AR) can contribute to the slow solar wind. Here, we compared the upflow region and the AR core and studied how the…

Solar and Stellar Astrophysics · Physics 2021-08-04 Krzysztof Barczynski , Louise Harra , Lucia Kleint , Brandon Panos , David H. Brooks

The measurement of extremely small displacements is of utmost importance, both for fundamental studies [1-4], and practical applications [5-7]. One way to estimate a small displacement is to measure the Doppler shift generated in light…

Instrumentation and Detectors · Physics 2019-01-30 Bethany J. Little , Julián Martínez-Rincón , Umberto Bortolozzo , Stefania Residori , John C. Howell

The variation in area of quiet magnetic network measured over the sunspot cycle should modulate the spatially averaged photospheric temperature gradient, since temperature declines with optical depth more gradually in magnetic flux tube…

Solar and Stellar Astrophysics · Physics 2017-01-25 Serena Criscuoli , Peter Foukal

We explore the temporal relationship between microwave/HXR emission and Doppler velocity during the impulsive phase of a solar flare on 2014 October 27 (SOL2014-10-27), which displays a pulse on the light curves in microwave (34 GHz) and…

Solar and Stellar Astrophysics · Physics 2017-05-24 Dong Li , Zongjun Ning , Yu Huang , Qingmin Zhang

The heating of ions and electrons due to turbulent dissipation plays a crucial role in the thermodynamics of the solar wind and other plasma environments. Using magnetic field and thermal plasma observations from the first two perihelia of…

Solar and Stellar Astrophysics · Physics 2023-04-12 Niranjana Shankarappa , Kristopher G. Klein , Mihailo M Martinović

Solar spicules have eluded modelers and observers for decades. Since the discovery of the more energetic type II, spicules have become a heated topic but their contribution to the energy balance of the low solar atmosphere remains unknown.…

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

Low-frequency turbulence in the solar chromosphere remains poorly understood. We address 1) the sources of low-frequency turbulence that potentially heat the chromosphere, and 2) how turbulence is transported and dissipated throughout the…