Results 61 to 70 of about 426 (165)

GNSS-RO Residual Ionospheric Error (RIE): A New Method and Assessment

Atmospheric Measurement Techniques
Abstract. GNSS radio occultation (RO) observations play an increasingly important role in monitoring climate changes and numerical weather forecasts in the upper troposphere and stratosphere. The magnitudes of the RO bending angle are small at these altitudes, and therefore residual ionospheric error (RIE) is critical to retrieve vertical profiles of ...
Dong L. Wu, Valery A. Yudin, Kyu-Myong Kim, Mohar Chattopadhyay, Lawrence Coy, Ruth S. Lieberman, C. C. Jude H. Salinas, Jae N. Lee, Jie Gong, Guiping Liu   +9 more
openaire   +4 more sources

Enhancing Low‐Latitude Ionospheric Irregularity Prediction With Generalized Linear Models

Space Weather, Volume 24, Issue 3, March 2026.
Abstract The ionosphere poses challenges for accurate forecasting due to its complexity and variability. Irregularities in the lower ionosphere are influenced by local time, season, geographic location, solar activity and space weather, complicating precise predictions.
Alysson Brhian, Marco A. Ridenti, Francisco Azpilicueta, Mauricio Gende, Marisa Roberto   +4 more
wiley   +1 more source

Beyond Geostrophic and Gradient Wind: Enhancing the Estimation of Climatic Wind Fields From Radio Occultation

Earth and Space Science, Volume 13, Issue 3, March 2026.
Abstract Wind approximations, such as geostrophic and gradient wind, are limited in their ability to accurately represent atmospheric conditions in the presence of significant planetary wave activity. Those approximations, while widely applied in synoptic‐scale wind field estimation, fail to capture the full complexity of atmospheric dynamics under ...
Johannes Unegg, I. Nimac, J. Danzer
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

Characterizing Small‐Scale Gravity Waves Generated by Hurricanes Through Convective Generation and Wind Filtering Effects

Earth and Space Science, Volume 13, Issue 3, March 2026.
Abstract Small‐scale gravity waves (GWs) generated by Hurricane Sam (2021), Fiona (2022), and Dora (2023) are studied using COSMIC‐2 GNSS‐radio occultation (RO) temperature retrievals and ERA5 reanalysis data set, from which we categorize three GW types that are commonly observed in the hurricanes studied.
Yuying Wang, Spiros Pagiatakis, Panagiotis Vergados   +2 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

Global Bottomside Ionospheric Modeling Based on GNSS‐RO Observations From the Tianmu‐1 Constellation

Space Weather, Volume 24, Issue 3, March 2026.
Abstract Radio occultation (RO) observations provide a crucial means for estimating the global Vertical Bottomside Electron Content (VBEC) in the ionosphere. However, the limited number of low Earth orbit (LEO) satellites in existing RO missions restricts the capability for high‐precision reconstruction of global VBEC spatiotemporal variations.
Linghuo Jian, Xiaodong Ren, Yingchuan Yang, Xuan Le, Xiaohong Zhang   +4 more
wiley   +1 more source

Seeking Optimal GNSS Radio Occultation Constellations Using Evolutionary Algorithms

Remote Sensing, 2019
Given the great achievements of the Constellation Observing System for Meteorology, Ionosphere, and Climate (COSMIC) mission in providing huge amount of GPS radio occultation (RO) data for weather forecasting, climate research, and ionosphere monitoring,
Xiaohua Xu, Yi Han, Jia Luo, Jens Wickert, Milad Asgarimehr   +4 more
doaj   +1 more source

Analysis on Global Es Layer Response to the May 2024 Geomagnetic Storm Through a Combination of Tianmu‐1 and COSMIC‐2 Radio Occultation Observations

Space Weather, Volume 24, Issue 3, March 2026.
Abstract The sporadic E (Es) layer, a key manifestation of ionosphere‐neutral atmosphere coupling, is highly sensitive to geomagnetic storms. Using more than 25,000 daily radio occultation profiles from the Tianmu‐1 and COSMIC‐2 constellations, this study investigates the global response of the Es layer to the May 2024 storm.
Sheng Guo, Sicheng Wang, Lei Shi, Zheng Sheng, Jia Bu   +4 more
wiley   +1 more source

Evaluation of COSMIC‐2 Satellite Data for foF2 and hmF2 Against Ground‐Based Ionosondes and the PyIRI (2020) Model Across Middle to Low Latitudes

Space Weather, Volume 24, Issue 2, February 2026.
Abstract This study presents a comprehensive evaluation of COSMIC‐2 satellite‐derived ionospheric peak parameters (foF2 and hmF2) against ground‐based ionosonde observations and a comparative analysis with PyIRI (2020) model estimates across middle to low latitudes for the period 2020–2024.
Ephrem Beshir Seba, Carla Jacobs, Matthieu Melcot, Stefaan Poedts   +3 more
wiley   +1 more source