Results 61 to 70 of about 910 (213)

Preliminary Assessment of BDS Radio Occultation Retrieval Quality and Coverage Using FY-3E GNOS II Measurements

Remote Sensing, 2023
The FengYun-3E Global Navigation Satellite System (GNSS) occultation sounder II (FY-3E GNOS II) was launched on 5 July 2021. For the first time, based on the new GNOS II sensor, this mission realizes radio occultation (RO) and reflectometry observations ...
Congliang Liu, Mi Liao, Yueqiang Sun, Xi Wang, Jiahui Liang, Xiuqing Hu, Peng Zhang, Guanglin Yang, Yan Liu, Jinsong Wang, Weihua Bai, Qifei Du, Xiangguang Meng, Peng Hu, Guangyuan Tan, Xianyi Wang, Junming Xia, Feixiong Huang, Cong Yin, Yuerong Cai, Wei Li, Peixian Li, Gottfried Kirchengast   +22 more
doaj   +1 more source

A Unified Vector Electromagnetic Framework for Ionospheric Scintillation and Polarization Effects in GNSS

Radio Science, Volume 61, Issue 6, June 2026.
Abstract The ionosphere imposes coupled amplitude, phase, and polarization distortions on trans‐ionospheric Global Navigation Satellite System (GNSS) signals, reflecting the structure and dynamics of electron‐density irregularities. Classical weak‐scatter theory provides a mature framework for interpreting amplitude and phase scintillation, but these ...
T. Durgonics, S. S. Beeck
wiley   +1 more source

Unconstrained GNSS Water Vapor Tomography With Real Data and LEO Augmentation

Geophysical Research Letters, Volume 53, Issue 10, 28 May 2026.
Abstract The availability of four complete GNSS constellations (GPS, GLONASS, BeiDou and Galileo) offers, for the first time, the possibility of performing water vapor tomographic inversions that do not rely on external data. A tomographic model that includes no external constraints and requires no first guess and no virtual observations is described ...
P. M. A. Miranda, G. A. Hajj, J. Teixeira, P. Mateus   +3 more
wiley   +1 more source

Comparative Assessment of Spire and COSMIC-2 Radio Occultation Data Quality

Remote Sensing, 2023
In this study, we investigate the performances of a commercial Global Navigation Satellite System (GNSS) Radio Occultation (RO) mission and a new-generation RO constellation, i.e., Spire and Constellation Observing System for Meteorology, Ionosphere, and
Cong Qiu, Xiaoming Wang, Kai Zhou, Jinglei Zhang, Yufei Chen, Haobo Li, Dingyi Liu, Hong Yuan   +7 more
doaj   +1 more source

Attributing Upper‐Tropospheric Warm Biases in CMIP6 Models to Ice Cloud‐Radiation Interaction Deficiencies Over Tropical Oceans

Geophysical Research Letters, Volume 53, Issue 9, 16 May 2026.
Abstract We assess the impact of hydrometeor radiative effects on tropical and subtropical Pacific air temperature anomalies (TAA) using Coupled Model Intercomparison Project Phase 6 (CMIP6) model simulations and satellite data. CMIP6 models are grouped by their treatment of frozen hydrometeors: SON2 (explicit cloud and falling ice), SON1 (simplified),
J.‐L. F. Li, Wei‐Liang Lee, Kuan‐Man Xu, J. H. Jiang, Yi‐Hui Wang, Yu‐Cian Tsai, S‐P. Ho, Qing Yue, Graeme Stephens, Jia‐Yuh Yu, Huiwen Chuang   +10 more
wiley   +1 more source

Joint 1DVar retrievals of tropospheric temperature and water vapor from Global Navigation Satellite System radio occultation (GNSS-RO) and microwave radiometer observations [PDF]

Atmospheric Measurement Techniques
Global Navigation Satellite System radio occultation (GNSS-RO) and microwave radiometry (MWR) are two of the most impactful spaceborne remote sensing techniques for numerical weather prediction (NWP).
K.-N. Wang, C. O. Ao, M. G. Morris, G. A. Hajj, M. J. Kurowski, F. J. Turk, A. W. Moore   +6 more
doaj   +1 more source

Artificial Intelligence in Autonomous Mobile Robot Navigation: From Classical Approaches to Intelligent Adaptation

Advanced Intelligent Systems, Volume 8, Issue 5, May 2026.
Artificial intelligence (AI) is reshaping autonomous mobile robot navigation beyond classical pipelines. This review analyzes how AI techniques are integrated into core navigation tasks, including path planning and control, localization and mapping, perception, and context‐aware decision‐making. Learning‐based, probabilistic, and soft‐computing methods
Giovanna Guaragnella, Angelo Cardellicchio, Cosimo Patruno, Massimiliano Nitti, Nicola Pedrocchi, Vito Renò   +5 more
wiley   +1 more source

Radar and Visual Odometry Integrated System Aided Navigation for UAVS in GNSS Denied Environment

Sensors, 2018
Drones are becoming increasingly significant for vast applications, such as firefighting, and rescue. While flying in challenging environments, reliable Global Navigation Satellite System (GNSS) measurements cannot be guaranteed all the time, and the ...
Mostafa Mostafa, Shady Zahran, Adel Moussa, Naser El-Sheimy, Abu Sesay   +4 more
doaj   +1 more source

GNSS-RO LEO satellite orbit optimization for Egypt and the Middle East region

Alexandria Engineering Journal, 2020
The “Radio Occultation (RO)” method is one from the simple, accurate and high resolution methods that produces a complete atmosphere model. Each region/country optimizes a “Low Earth Orbiter (LEO)” satellite orbit that covers its climate requirements by processing the “Global Navigation Satellite System (GNSS)” received signal.
Ibrahim Fouad Ghoniem, Ashraf El-Kutb Mousa, Gamal El-Fiky   +2 more
openaire   +2 more sources

Climatic Higher‐Order Balanced Winds Beyond Geostrophic and Gradient Wind Fields

Earth and Space Science, Volume 13, Issue 5, May 2026.
Abstract We present a novel approach to derive three‐dimensional Climatic Higher‐Order Balanced (CHOB) wind fields from thermodynamic state variables in the free troposphere and stratosphere. The CHOB method is developed for monthly synoptic‐scale wind field estimation, utilizing commonly used balanced winds (geostrophic and gradient wind) enhanced by ...
I. Nimac, J. Unegg, J. Danzer
wiley   +1 more source