Results 31 to 40 of about 251 (164)

Calibration and Fusion of GOLD‐Inferred TEC Data With Ground‐Based TEC

Space Weather, Volume 24, Issue 6, June 2026.
Abstract Ground‐based Global Navigation Satellite System (GNSS) receivers provide primary total electron content (TEC) measurements used to monitor ionospheric variability, yet their sparse distribution over oceanic and equatorial regions limits global coverage and model accuracy.
Maria Smirnova, Shasha Zou, Grace Kwon, Hang Liu, Yang Chen   +4 more
wiley   +1 more source

Introducing Reflected GNSS TEC Data Into ANCHOR Ionospheric Data Assimilation Model

Space Weather, Volume 24, Issue 5, May 2026.
Abstract ANCHOR is a novel data assimilation (DA) algorithm developed at the U.S. Naval Research Laboratory to improve ionospheric nowcasting by increasing accuracy and decreasing computational cost. As a parameterized DA model, ANCHOR represents the ionosphere using physical parameters such as the F2 layer peak (Nm $Nm$F2), which characterizes a ...
Brenna Royersmith, Victoriya V. Forsythe, Brian Breitsch, Meghan R. Burleigh, Kate A. Zawdie, Y. Jade Morton   +5 more
wiley   +1 more source

LOBEFIT: LEO satellite broadcast ephemeris fitting open-source software based on automatic differentiation technique

SoftwareX
LEO (Low Earth Orbit)-based PNT (Positioning, Navigation and Timing) has become a research topic of much interest and a focus of development. As LEO satellites for PNT are expected to independently provide space-time references in the future, similar to ...
Zhao Xi, Yu Baoguo, Luo Bin
doaj   +1 more source

Ni Single‐Atom Modulation of Ti‐O Covalency Boosts Ammonia Oxidation Electrocatalysis

Advanced Science, Volume 13, Issue 17, 23 March 2026.
A Ni single‐atom‐induced enhancement of Ti‐O covalency in Ni SAC@TiO2 generates abundant active sites and promotes selective NHx‐NHy mediated N2 evolution while suppressing poisonous NOx formation, achieving nearly doubled AOR activity with excellent durability.
Subhash Chandra Shit, Dayoung Kwon, Nhi Thi Yen Phan, Hyo Won Kim, Jucheol Park, Jeong‐hyeon Lee, Hyeyoung Shin, Wooyul Kim   +7 more
wiley   +1 more source

System Guidelines for Impact of PRS Inter-Satellite Interference in NTN PNT With LEO Constellations

IEEE Open Journal of the Communications Society
This article investigates the interference challenges of Non-Terrestrial Networks (NTN) enabling Positioning, Navigation and Timing (PNT) services. Current mobile communication standards already provide native positioning methods for terrestrial networks
Tobias Grober, Jose A. del Peral-Rosado, Thomas Pany   +2 more
doaj   +1 more source

The Non‐Linear Dependence of Daily Maximum Ionospheric Total Electron Content on F10.7

Space Weather, Volume 24, Issue 2, February 2026.
Abstract Daily 10.7 cm solar flux, the F10.7 index, is a key parameter for the ionospheric state. Global maps of ionospheric Total Electron Content (TEC) offer almost continuous multidecadal coverage. We find that the global daily maximum of TEC saturates with daily F10.7.
M. A. Cafolla, S. C. Chapman, N. W. Watkins, O. P. Verkhoglyadova   +3 more
wiley   +1 more source

Breaking the Cyclic Prefix Barrier: Zero-Padding Correlation Enables Centimeter-Accurate LEO Navigation via 5G NR Signals

Remote Sensing
Low Earth orbit (LEO) satellites offer a revolutionary potential for positioning, navigation, and timing (PNT) services due to their stronger signal power and rapid geometric changes compared to traditional global navigation satellite systems (GNSS ...
Lingyu Deng, Yikang Yang, Jiangang Ma, Tao Wu, Xingyou Qian, Hengnian Li   +5 more
doaj   +1 more source

Consistency Analysis of MCSK Navigation Augmentation Signal Characteristics for LEO Constellations Based on Space–Ground Data

IET Radar, Sonar &Navigation, Volume 20, Issue 1, January/December 2026.
This paper addresses the issue of space–ground signal characteristic consistency for MCSK‐based low Earth orbit (LEO) navigation augmentation. A comprehensive evaluation framework, integrating multidimensional indicators and hierarchical correlation analysis, is proposed. Based on ground and in‐orbit measurement data from a representative constellation,
Yao Guo, Guang Li, Hong Zhang, Yongnan Rao, Wenbin Gong   +4 more
wiley   +1 more source

A Unified Optimization Framework for LEO Hybrid Constellations Using an Improved Continuous Coefficient Method

Advances in Astronomy, Volume 2026, Issue 1, 2026.
Low Earth orbit (LEO) constellations are increasingly deployed to provide integrated services such as communication, navigation augmentation, and remote sensing. However, traditional constellation designs—such as Walker, streets‐of‐coverage (SoC), and Flower constellations—rely on distinct parameter sets, making unified optimization of hybrid ...
Lin Pan, Lan Du, Zhongkai Zhang, Lundong Zhang, Zejun Liu, Peiyuan Zhou, Chonghui Li, Jianguo Yan   +7 more
wiley   +1 more source

HPDL Variant Type Correlates With Clinical Disease Onset and Severity

Annals of Clinical and Translational Neurology, Volume 12, Issue 7, Page 1360-1367, July 2025.
ABSTRACT Objective Recently, a mitochondrial encephalopathy due to biallelic HPDL variants was described, associated with a broad range of clinical manifestations ranging from severe, infantile‐onset neurodegeneration to adolescence‐onset hereditary spastic paraplegia. HPDL converts 4‐hydroxyphenylpyruvate acid (4‐HPPA) into 4‐hydroxymandelate (4‐HMA),
Eun Hye Lee, Olivia Kim‐Mcmanus, Jennifer H. Yang, Richard Haas, Maha S. Zaki, Ghada M. H. Abdel‐Salam, Yuji Nakamura, Mohamed S. Abdel‐Hamind, Darius Ebrahimi‐Fakhari, Julian E. Alecu, Nicola Brunetti‐Pierri, Varunvenkat M. Srinivasan, Vykuntaraju K. Gowda, Stephanie Gross, Yasemin Alanay, Paria Najarzadeh Totbati, Manya Yadavilli, Liana Friedman, Naomi Meave Ojeda, Joseph G. Gleeson   +19 more
wiley   +1 more source