Results 71 to 80 of about 705,367 (158)

Impact of Sudden Stratospheric Warming and Elevated Stratopause Events on the Very Low Frequency Radio Signal

Journal of Geophysical Research: Space Physics, Volume 130, Issue 3, March 2025.
Abstract Sudden Stratospheric Warmings (SSW) and Elevated Stratopause (ES) events are mid‐to‐high latitudinal, atmospheric wave‐driven phenomena leading to significant changes in wind, temperatures, and vertical mass transport, especially at stratospheric and mesospheric altitudes.
H. Schneider, V. Wendt, D. Banyś, M. Hansen, M. Clilverd, P. T. Verronen   +5 more
wiley   +1 more source

Observations of Unusual Postsunrise Interhemispheric Geomagnetic Conjugate Super Plasma Depletions at Midlatitudes During the Recovery Phase of the November 2003 Superstorm

Space Weather, Volume 23, Issue 2, February 2025.
Abstract This study reports an extreme ionospheric plasma depletion event over the Eastern Pacific from postmidnight to early morning during the superstorm's recovery phase on 21 November 2003 observed by the DMSP F13, ROCSAT‐1, GRACE, and CHAMP satellites, and two ground‐based GPS receivers. The depletion and its interhemispheric geomagnetic conjugate
Hailun Ye, Xianghui Xue, Yang‐Yi Sun, Tao Yu, Wen Yi, Jianfei Wu, Bingkun Yu, Jianyuan Wang, Chi Long, Baozhu Zhou, Zezhong Li, Chong Wang, Tingdi Chen, Xiankang Dou   +13 more
wiley   +1 more source

ELoran signal message recognition algorithm based on GTCN‐transformer

IET Radar, Sonar &Navigation, Volume 19, Issue 1, January/December 2025.
This paper introduces a novel GTCN‐Transformer network designed for the specific task of recognising message in eLoran pulse group signal. The network is constructed by enhancing the architecture of Temporal Convolutional Networks (TCN) and integrating the Transformer mechanism.
Kai Zhang, Fan Yang, Weidong Wang, Bingqian Wang   +3 more
wiley   +1 more source

Wave Parameter Inversion Based on Sea Clutter Characteristics

Remote Sensing
Accurate acquisition of wave parameters is important for marine monitoring and target identification. Traditional methods are limited in sea state adaptability, real-time observation, and inversion accuracy.
Xiao Li, Xin Li, Huaiyun Peng, Xinyu Xu, Chunzhi Hou   +4 more
doaj   +1 more source

Study of wind direction factor based on sea clutter in littoral environments

The Journal of Engineering, 2019
Wind direction factor, as a part of some empirical sea clutter models of the normalised radar cross-section (NRCS), is closely related to wind direction angle, grazing angle and radar wavelength.
Li Xin, Zhao Peng, Shui Penglang, Xia Xiaoyun, Xu Shuwen   +4 more
doaj   +1 more source

Investigations on the prediction of radiowave propagation in urban microcell environments using ray-tracing methods

, 1996
Future personal and mobile radiocommunication systems may use microcells to achieve high capacity. Base station antennas will be located at low heights, below the roof height of surrounding buildings, to restrict the coverage area of each cell.
Brown, P.G., Constantinou, C.C.; id_orcid   +1 more
core   +3 more sources

Groundwave propagation at short ranges and accurate source modeling

, 2013
Radiowave propagation models have long been used in long-range communication and/or radar systems. Different models use different sources. Observed and calculated results are therefore usually normalized, either against maximum or free-space values, or ...
Sevgi, Levent, Apaydın, Gökhan
core   +1 more source

Exploring Marine Atmospheric Ducts: Current Sensing and Emerging Trends

Remote Sensing
Tropospheric refraction significantly impacts the propagation of ultrashort- and microwave-frequency radio waves over marine environments. Atmospheric ducting, the most common super-refractive structure, allows radio waves to travel over the horizon ...
Jin-Peng Zhang, Yu-Jing Li, Han-Jie Ji, Huai-Yun Peng, Xiang-Ming Guo, Yu-Sheng Zhang   +5 more
doaj   +1 more source

Optical absorption and energy-loss spectra of aligned carbon nanotubes [PDF]

, 2001
PACS. 78.66.Sq Composite materials – 41.20.Jb Electromagnetic wave propagation; radiowave propagation – 61.46.+w Nanoscale materials: clusters, nanoparticles, nanotubes, and nanocrystals,
F.J. García-Vidal, J.M. Pitarke, García-Vidal, F. J., J. M. Pitarke, F. J. García-Vidal, Pitarke, José María   +5 more
core   +1 more source

Modeling of Diffraction Effects in Urban Radiowave Propagation

, 2017
A comparative study of some theoretical and numerical models is presented in the solution of two-dimensional urban radiowave propagation problems. The path loss is computed by GO+UTD (geometric optics + uniform theory of diffraction), two-way SSPE (split
ÖZGÜN, ÖZLEM
core