Results 41 to 50 of about 427 (158)

An Ionospheric Storm Scale Index Based on TEC: Comparative Analysis for China Region

Space Weather, Volume 24, Issue 8, August 2026.
Abstract Defining a standardized ionospheric storm scale is challenging given the ionosphere's inherent complexity and susceptibility to multiple driving factors. In this study, a novel ionospheric storm scale (ISS) index is developed based on statistical analysis of total electron content (TEC) data from 257 ground‐based GNSS stations across China ...
Shuangshuang Shi, Yunfei Shi, Kefei Zhang, Bingfeng Tan, Fucheng Song, Peng Sun, Yu Li, Yifan Liu, Shouxing Zhao   +8 more
wiley   +1 more source

Izračun položaja GPS-satelita iz podatkov oddanih efemerid : GPS-Orbit Computation from Broadcast Ephemeris Data [PDF]

Geodetski Vestnik, 2004
The article describes the theoretical point of view of the GPS-broadcast ephemerides application. Beside the raw GPS observations, any kind of GPS ephemerides represents indispensable data in the GPS processing engine.
Bojan Stopar, Polona Pavlovčič Prešeren   +1 more
doaj  

Impacts of Satellite Orbit and Clock on Real-Time GPS Point and Relative Positioning

Sensors, 2017
Satellite orbit and clock corrections are always treated as known quantities in GPS positioning models. Therefore, any error in the satellite orbit and clock products will probably cause significant consequences for GPS positioning, especially for real ...
Junbo Shi, Gaojing Wang, Xianquan Han, Jiming Guo   +3 more
doaj   +1 more source

A Flexible Ephemeris Representation for GNSS and Alternative PNT Signal Sources Using B-Splines

Navigation, 2023
Most global navigation satellite systems (GNSSs) ephemeris representations require straightforward, albeit specialized algorithms to compute the transmitter position at a time of interest.
Mikaela Dobbin, Penina Axelrad
doaj   +1 more source

High‐Latitude GPS Position Error During Substorms

Space Weather, Volume 24, Issue 6, June 2026.
Abstract Substorms produce rapid fluctuations in Global Navigation Satellite System (GNSS) signals, leading to degraded positioning performance at high latitudes. This study investigates the correlation of auroral structures on Global Positioning System (GPS) Precise Point Positioning (PPP) error during three substorm events with different strengths ...
Weixuan Liao, Yukitoshi Nishimura, Waqar Younas, Wen Li, Keith M. Groves, Eric F. Donovan, Vassilis Angelopoulos   +6 more
wiley   +1 more source

Accurate and Rapid Broadcast Ephemerides for Beidou-Maneuvered Satellites

Remote Sensing, 2019
The geostationary earth orbit (GEO) and inclined geosynchronous orbit (IGSO) satellites of the Beidou navigation satellite system are maneuvered frequently. The broadcast ephemeris can be interrupted for several hours after the maneuver.
Jing Qiao, Wu Chen, Shengyue Ji, Duojie Weng   +3 more
doaj   +1 more source

Refinement of a Framework for Moving Aircraft River Velocimetry (MARV) and Application to Particle Tracking Along Alaskan Rivers

Water Resources Research, Volume 62, Issue 5, May 2026.
Abstract Information on river velocities enhances understanding flood hazards, evaluating habitat conditions, and predicting the transport of floating materials. In this follow‐up study, we used data from two new sites, one with a more complex morphology and the other with a lower suspended sediment concentration, to provide further evidence that ...
Carl J. Legleiter, Paul J. Kinzel, Mark Laker, Jeffrey S. Conaway   +3 more
wiley   +1 more source

Real-Time Precise Point Positioning Method Considering Broadcast Ephemeris Discontinuities

Navigation
With advancements in the broadcast ephemeris accuracy of global navigation satellite systems (GNSSs), precise point positioning based on broadcast ephemeris (BE-PPP) is gradually showing promising prospects.
Quanrun Cheng, Junping Chen, Yize Zhang, Chao Yu   +3 more
doaj   +1 more source

A Robust Autonomous Timekeeping Scheme For Navigation Constellations Using Inter‐Satellite Links

Electronics Letters, Volume 62, Issue 1, January/December 2026.
This letter proposes a robust autonomous timekeeping scheme for navigation constellations that utilises inter‐satellite link measurements to mitigate on‐orbit clock anomalies. By cross‐evaluating clock stability between two independent ensemble groups and dynamically optimising their weights via particle swarm optimisation, the method effectively ...
Lihao Yin, Mingyuan Zhang, Qianyi Ren, Wenbin Gong   +3 more
wiley   +1 more source

Enhancing Security and Transparency in Satellite Data Transactions Using Ethereum‐Based Blockchain

The Journal of Engineering, Volume 2026, Issue 1, January/December 2026.
This study presents an Ethereum‐based framework for securing satellite data transactions using ERC1155 tokenization, Proof of Authority consensus, and Threshold Cryptography. The system achieves low latency, high throughput, and significantly reduced gas costs while providing strong resistance against MITM, Sybil, and reentrancy attacks.
Saha Reno, Mohammad Jishan Ahmad Shipu, Sumaiya Hussain Tanha, Mohammad Molla Habib   +3 more
wiley   +1 more source