Results 21 to 30 of about 806 (126)

Accurate Ionospheric TEC Prediction With a Causal Attention Network at Northern EIA Crests

Journal of Geophysical Research: Machine Learning and Computation, Volume 3, Issue 3, June 2026.
Abstract As the Sun approaches the peak of its 25th activity cycle, precise ionospheric forecasting has become increasingly challenging. Low‐latitude regions have emerged as a persistent bottleneck for space weather operations. Extensive evidence reveals that existing AI models exhibit significant performance degradation in these regions, demonstrating
Tong Liu, Wu Chen, Zexin Lu, Wenlong Zhang, Yuhang Lu, Feng Wang, Mengfei Sun, Wenfeng Nie, Junsheng Ding, Yufang He, Bo Chen   +10 more
wiley   +1 more source

Geomorphic Effectiveness of an Extreme Flood in a Mountain River: Evidence From Pre‐ and Post‐Event Surveys in a Subtropical Region of Southern Brazil

Hydrological Processes, Volume 40, Issue 5, May 2026.
The extreme flooding of April 2024 caused a complete “geomorphic reset”, resulting in a 24% widening of the channel and a transition to critical or supercritical flow regimes. The energy of the event broke through the stable armouring layer, reducing the armouring ratio from 7.9 to 4.9 and intensely removing fine sediments from the subsurface.
Gabriel Augusto Feyh, Jean Paolo Gomes Minella, Eno Darci Saatkamp, Lidiane Buligon, Gustavo Henrique Merten, Felipe Bernardi, Cristiano Carvalho da Silva, Angelo Garcia Costa, Alice Prates Bisso Dambroz   +8 more
wiley   +1 more source

RT‐FAIRS: Real‐Time Factor‐Adjusted Ionospheric Residual Statistics Approach for Generating Accuracy Information in Global Ionospheric Maps

Space Weather, Volume 24, Issue 4, April 2026.
Abstract Ionospheric delays remain a major error source in Global Navigation Satellite Systems (GNSS). The International GNSS Service (IGS) provides Global Ionospheric Maps (GIMs) that offer vertical total electron content (VTEC) estimates together with RMS maps as accuracy information.
Ang Li, Ningbo Wang, Manuel Hernández‐Pajares, Ang Liu, Zishen Li, Axel Rülke, Andrzej Krankowski, Heng Yang, Reza Ghoddousi‐Fard, Adam Froń, Zhouyu Zhang   +10 more
wiley   +1 more source

Characterizing the Role of Storm‐Time High‐Latitude Ionospheric Structures in GPS Position Accuracy in Antarctica: May 2024 Storm

Space Weather, Volume 24, Issue 4, April 2026.
Abstract This study investigates the impact of high‐latitude ionospheric irregularities on global positioning system (GPS) position accuracy during the 10–11 May 2024 geomagnetic storm. Using data from ground‐based GPS receivers and an all‐sky camera in Antarctica, we examined evolution of GPS vertical total electron content, phase fluctuations, and ...
Waqar Younas, Yukitoshi Nishimura, Weixuan Liao, Josh L. Semeter, Sebastijan Mrak, Y. Jade Morton, Keith M. Groves, Tetsuo Motoba, Tim Everett   +8 more
wiley   +1 more source

MSE-impact of PPP-RTK ZTD estimation strategies

Advances in Space Research, 2018
In PPP-RTK network processing, the wet component of the zenith tropospheric delay (ZTD) cannot be precisely modelled and thus remains unknown in the observation equations. For small networks, the tropospheric mapping functions of different stations to a given satellite are almost equal to each other, thereby causing a near rank-deficiency between the ...
Wang, K. (author), Khodabandeh, A. (author), Teunissen, P.J.G. (author)   +2 more
openaire   +5 more sources

PPP‐RTK Atmospheric Correction Generation and Service Applicability: A Case Study During Typhoon Saola and Moderate Geomagnetic Disturbances in Hong Kong

Space Weather, Volume 24, Issue 3, March 2026.
Abstract Complex space weather, such as typhoons and solar activity, can cause heavy rainfall and ionospheric disturbances, affecting the quality of Global Navigation Satellite System (GNSS) signals. Among GNSS positioning techniques, Precise Point Positioning Real‐time Kinematic (PPP‐RTK) uses atmospheric corrections and bias products to achieve fast ...
Jiahuan Hu, Xuanyu Qu, Pan Li, Mengyu Ding, Jiadi Dai, Xiaoli Ding, Wu Chen   +6 more
wiley   +1 more source

A Novel Robust High‐Precision Ionospheric Delay Modeling for PPP‐RTK Using Crowdsourced Data

Space Weather, Volume 24, Issue 2, February 2026.
Abstract The performance of PPP‐RTK is critically dependent on the quality of ionospheric corrections derived from a reference network. While the proliferation of mass‐market Global Navigation Satellite System (GNSS) devices offers a promising crowdsourcing opportunity to densify or replace this infrastructure, it introduces the formidable challenge of
Bo Wang, Jiaxi Zhu, Zhilu Wu, Dejin Zhang, Zhao Li, Minsi Ao, Shengfeng Gu   +6 more
wiley   +1 more source

A 4D tomographic ionospheric model to support PPP-RTK

Journal of Geodesy, 2019
Successful implementation of integer ambiguity resolution enabled precise point positioning (aka PPP-RTK) algorithms is inextricably linked to the ability of a user to perform near real-time positioning by quickly and reliably resolving the integer carrier-phase ambiguities.
G. Olivares-Pulido, M. Terkildsen, K. Arsov, P. J. G. Teunissen, A. Khodabandeh, V. Janssen   +5 more
openaire   +4 more sources

Characterizing North‐South Ionospheric Gradients During Geomagnetic Storms: A Variogram Enhancement for Wide Area Ionospheric Models

Space Weather, Volume 24, Issue 1, January 2026.
Abstract The intensified solar maximum of Cycle 25 has heightened space weather risks to Global Navigation Satellite Systems (GNSS), where geomagnetic storms critically challenge Positioning, Navigation, and Timing (PNT) availability. Current wide‐area ionospheric models may fail to resolve extreme latitudinal Total Electron Content (TEC) gradients ...
Tong Liu, Yiping Jiang, Bo Chen, Jian Liu, Yufang He, Wu Chen   +5 more
wiley   +1 more source

Regional Medium‐Scale Traveling Ionospheric Disturbance Propagation Model Based on BDS GEO Satellites

Space Weather, Volume 24, Issue 1, January 2026.
Abstract Accurate modeling of traveling ionospheric disturbances (TIDs) is essential for characterizing their spatiotemporal variations and mitigating their effects on Global Navigation Satellite System (GNSS) precise positioning. This study develops a regional medium‐scale TID (MSTID) propagation model using BeiDou geostationary orbit (GEO) total ...
Dengkui Mei, Xiaohong Zhang, Xiaodong Ren, Xuan Le, Wentao Yang, Ahmed Abdelaziz   +5 more
wiley   +1 more source