Results 31 to 40 of about 705,367 (158)

A New SLF/ELF Algorithm of Fields Excited by a Radiator in a Soil Foundation in the Earth–Ionosphere Cavity

Atmosphere, 2023
Abnormal electromagnetic radiation associated with seismic activity has been reported across a wide range of frequencies, but its primary energy is concentrated in the super-low-frequency (SLF) and extremely low-frequency (ELF) bands.
Yuanxin Wang, Jutao Yang, Shuji Hao, Jing Chen, Yonggan Liang, Yanshuai Zheng   +5 more
doaj   +1 more source

Radiowave Propagation in Satellite Communications

, 1986
Radiowave Propagation in Communications was written with two basic objec­ tives: (l) to present an up-to-date review of the major radiowave propagation phenomena which hinder reliable space communications, and (2) to describe how these propagation ...
Ippolito, Louis J.
core   +1 more source

Estimating Ionospheric Phase Scintillation Indices in the Polar Region from 1 Hz GNSS Observations Using Machine Learning

Remote Sensing
Ionospheric scintillation represents a disturbance phenomenon induced by irregular electron density variations, predominantly occurring in equatorial, auroral, and polar regions, thereby posing significant threats to Global Navigation Satellite Systems ...
Zhuojun Han, Ruimin Jin, Longjiang Chen, Weimin Zhen, Huaiyun Peng, Huiyun Yang, Mingyue Gu, Xiang Cui, Guangwang Ji   +8 more
doaj   +1 more source

Comparative Analysis of Intelligent Optimization Algorithms for Atmospheric Duct Inversion Using Automatic Identification System Signals

Remote Sensing, 2023
Using intelligent optimization algorithms to retrieve atmospheric duct parameters by monitoring automatic identification system (AIS) signals at sea is a new passive remote sensing technology for atmospheric ducts.
Li-Feng Huang, Cheng-Guo Liu, Zhi-Peng Wu, Li-Jun Zhang, Hong-Guang Wang, Qing-Lin Zhu, Jie Han, Ming-Chen Sun   +7 more
doaj   +1 more source

Simulation of localized electron density enhancement caused by high-pressure H2O gas release in ionosphere

AIP Advances, 2023
Based on the continuity and momentum equations, a self-consistent simulation model is developed for describing the localized electron density enhancement caused by high-pressure H2O gas release in the ionosphere.
Yonggan Liang, Ruihuan Tian, Bin Xu, Xiaonan Jiang, Jutao Yang, Jian Wu, Jie Feng, Hui Li, Shuji Hao, Zhengzheng Ma   +9 more
doaj   +1 more source

Tropospheric Refractivity Profile Estimation by GNSS Measurement at China Big-Triangle Points

Atmosphere, 2021
Atmospheric radio refractivity has an obvious influence on the signal transmission path and communication group delay effect. The uncertainty of water vapor distribution is the main reason for the large error of tropospheric refractive index modeling ...
Xiang Dong, Fang Sun, Qinglin Zhu, Leke Lin, Zhenwei Zhao, Chen Zhou   +5 more
doaj   +1 more source

Corner and rooftop diffraction in radiowave propagation prediction tools:A review

, 1998
Accurate radiowave propagation prediction tools are essential for the optimal design of future mobile telecommunication services. In recent years, ray-optical methods have been gaining in popularity, especially for urban radiowave propagation prediction.
Demetrescu, C., Mehler, M.J., Constantinou, C.C.; id_orcid   +2 more
core   +3 more sources

Machine Learning-Based Estimation of foF2 and MUF(3000)F2 Using GNSS Ionospheric TEC Observations

Remote Sensing
This study developed machine learning models using different algorithms, including support vector machine (SVM), random forest (RF), and backpropagation neural network (BPNN), to estimate the critical frequency of the F2 layer (foF2) and the maximum ...
Yuhang Zhang, Ming Ou, Liang Chen, Yi Hao, Qinglin Zhu, Xiang Dong, Weimin Zhen   +6 more
doaj   +1 more source

Feasibility Study of Microwave Radiometer Neural Network Modeling Method Based on Reanalysis Data

Atmosphere
To address the challenge of microwave radiometer modeling in regions lacking radiosonde data, this study proposes a neural network retrieval method based on high-resolution the Final Reanalysis (FNL) reanalysis data and validates its feasibility.
Xuan Liu, Qinglin Zhu, Xiang Dong, Houcai Chen, Tingting Shu, Wenxin Wang, Bin Xu   +6 more
doaj   +1 more source

Automatic Detection and Localization of Space Hurricanes Based on Deep Learning

Space Weather, Volume 24, Issue 5, May 2026.
Abstract Space hurricanes are distinct space weather phenomena that occur during extremely quiet geomagnetic conditions, and exhibit hurricane‐like cyclonic auroral bright spot structures. This phenomenon can induce severe space weather effects, including radio communication disruptions, navigation and positioning errors, and over‐the‐horizon radar ...
Yu‐Han Li, Duan Zhang, Qing‐He Zhang, Jin Wang, Kjellmar Oksavik, Xiao‐Ping Jiang, Zan‐Yang Xing, Hui‐Gen Yang, Yong Wang, Yu‐Zhang Ma, Yan‐Ju Sun, Sheng Lu, Bian‐Long Zhao, Jia‐Chen Zhao, Wen‐Qian Chen, Xiang‐Yu Wang, Zhi‐Feng Xiu, Shi‐Gang Zheng   +17 more
wiley   +1 more source