Results 21 to 30 of about 1,467 (239)

Performance Assessment of Multi-GNSS PPP Ambiguity Resolution with LEO-Augmentation

Remote Sensing, 2023
The fast motion of low Earth orbit (LEO) satellites provides rapid geometric changes in a short time, which can accelerate the initialization of precise point positioning (PPP).
Qin Li, Wanqiang Yao, Rui Tu, Yanjun Du, Mingyue Liu   +4 more
doaj   +1 more source

Optimal Progressive Pitch for OneWeb Constellation with Seamless Coverage

Sensors, 2022
Large-scale broadband low earth orbit (LEO) satellite systems have become a possibility due to decreased launch costs and rapidly evolving technology. Preventing huge LEO satellite constellations from interfering with the geostationary earth orbit (GSO ...
Cheng Zou, Haiwang Wang, Jiachao Chang, Fengwei Shao, Lin Shang, Guotong Li   +5 more
doaj   +1 more source

Rethinking LEO constellations routing

International Journal of Satellite Communications and Networking
SummaryThis study investigates the unsplittable multicommodity flow (UMCF) as a routing algorithm for LEO constellations. Usually, LEO routing schemes enable the Floyd–Warshall algorithm (shortest path) to minimize the end‐to‐end latency of the flows crossing the constellation.
Paul Grislain, Alexia Auddino, Anna Barraqué, François Lamothe, Oana Hotescu, Jérôme Lacan, José Radzik, Emmanuel Lochin   +7 more
openaire   +2 more sources

5G NB-IoT via low density LEO Constellations

, 2021
5G NB-IoT is seen as a key technology for providing truly ubiquitous, global 5G coverage (1.000.000 devices/km2) for machine type communications in the internet of things. A non-terrestrial network (NTN) variant of NB-IoT is being standardized in the 3GPP, which along with inexpensive and non-complex chip-sets enables the production of competitively ...
Sørensen, René Brandborg, Møller, Henrik Krogh, Koch, Per   +2 more
openaire   +3 more sources

Communication and navigation integration for LEO constellations:status, opportunities, and challenges

Dianxin kexue, 2023
With the growing maturity of millimeter wave technology and high-throughput satellite communication technology, as well as the urgent need for global broadband communication services, the construction of LEO giant communication constellation has ...
Yafei ZHAO, Bing YAN, Yaohua SUN, Mugen PENG   +3 more
doaj   +2 more sources

Modelica-Based Modeling on LEO Satellite Constellation

Linköping Electronic Conference Proceedings, 2021
The new generation of LEO (Low Earth Orbit) communication satellite constellations have the advantages of low latency, strong signals, and global coverage. In order to achieve global coverage, the LEO satellite constellations are often very large, with a large number of satellites, which puts forward high requirements for the overall design, operation ...
null Liu Chan, null Chen Liping, null Qu Yan, null Zhou Fanli, null Qian Yikai   +4 more
openaire   +2 more sources

Analysis on BDS-3 Autonomous Navigation Performance Based on the LEO Constellation and Regional Stations

Remote Sensing, 2023
The global navigation satellite system (GNSS) is developing rapidly, and the related market applications and scientific research are increasing. Studies based on large low Earth orbit (LEO) satellite constellations have become research hotspots.
Baopeng Xu, Xing Su, Zhimin Liu, Mudan Su, Jianhui Cui, Qiang Li, Yan Xu, Zeyu Ma, Tao Geng   +8 more
doaj   +1 more source

LEO constellation optimization for LEO enhanced global navigation satellite system (LeGNSS)

Advances in Space Research, 2020
Abstract Low Earth Orbit (LEO) enhanced Global Navigation Satellite System (LeGNSS) has been recognized as the promising positioning system in the near future where mega-constellations of LEO satellites are used for precise positioning. Fast Precise Point Positioning (PPP) convergence can be achieved if LEO constellations are employed into current ...
Haibo Ge, Bofeng Li, Liangwei Nie, Maorong Ge, Harald Schuh   +4 more
openaire   +3 more sources

Mechanisms of IgE‐mediated food allergy and the role of allergen‐specific B cells

FEBS Letters, EarlyView.
Food allergy arises when allergen‐specific B cells preferentially produce immunoglobulin E (IgE) antibodies against harmless foods. This article explains the mechanisms driving IgE‐mediated reactions, highlights the central role of these B cells, and discusses how natural tolerance (NT) and oral immunotherapy (OIT) can reshape allergic immune responses.
Juan‐Felipe López, Özge Yilmaz Ardicli, Mübeccel Akdis   +2 more
wiley   +1 more source

Acoustic Measures Capture Speech Dysfunction in Spinocerebellar Ataxia

Annals of Clinical and Translational Neurology, EarlyView.
ABSTRACT Objective Spinocerebellar ataxias (SCA) are hereditary cerebellar degenerative disorders with a common feature of dysarthria, involving impaired phonatory and articulatory control of speech, thereby affecting social communication. In this study, we investigated whether acoustic measures could objectively measure speech dysfunction and identify
Zena Fadel, Charlotte Hennessey, Hannah Lee, Pia Parekh, Sheng‐Han Kuo, Ami Kumar   +5 more
wiley   +1 more source