Results 51 to 60 of about 424 (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

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

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

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

Applying Hpo Indices to Empirical Thermospheric Density Models During Geomagnetic Storms

Earth and Space Science, Volume 13, Issue 2, February 2026.
Abstract Accurate atmospheric drag modeling is essential for precise orbit determination and prediction of Low Earth Orbit satellites. A key component is the thermospheric density, typically estimated using empirical models driven by geomagnetic activity indices such as the 3‐hr Kp or ap.
Kemin Zhu, Jizhang Sang, Xianjie Li, Lei Liu, Yangbo Qian, Shengfu Xia   +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

AI‐Based Improvement of IRI‐2020 Electron Density Profiles With COSMIC Radio Occultation Data

Space Weather, Volume 24, Issue 2, February 2026.
Abstract In this study, we propose an AI‐based method to improve the electron density profiles generated by the International Reference Ionosphere (IRI)‐2020 model using the Constellation Observing System for Meteorology, Ionosphere, and Climate (COSMIC) radio occultation (RO) data.
Eun‐Young Ji, Yong‐Jae Moon, Young‐Sil Kwak, Kangwoo Yi, Jeong‐Heon Kim, Woong Jeon   +5 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

Dynamic Neural‐Model‐Based Predictive Control for Autonomous Wheel‐Legged Robot System

CAAI Transactions on Intelligence Technology, Volume 11, Issue 1, Page 83-97, February 2026.
ABSTRACT Mobile wheel‐legged robots exhibiting mobility, stability and reliability have garnered heightened research attention in demanding real‐world scenarios, especially in material transport, emergency response and space exploration. The kinematics model merely delineates the geometric relationship of the controlled objective, disregarding force ...
Jiehao Li, Junzheng Wang, Hongbo Gao, Xiwen Luo, C. L. Philip Chen   +4 more
wiley   +1 more source

Direct Observational Evidence of the Mesoscale Gravity Wave Modulations on Low‐Latitude Sporadic E Layer

Geophysical Research Letters, Volume 53, Issue 2, 28 January 2026.
Abstract Sporadic E (Es) layer plays essential role in ionosphere‐atmosphere coupling. Theoretical simulations show that the atmospheric gravity waves (GWs) in the lower thermosphere are the main modulatory source on Es dynamics at small spatial scales and short periods.
Junyi Wang, Xinan Yue, Xu Zhou, Yihui Cai, Feng Ding, Jorge L. Chau, David C. Fritts, Juha Vierinen, Alan Z. Liu, Baiqi Ning   +9 more
wiley   +1 more source