Results 41 to 50 of about 467 (182)

Control System for the Navigation of the Agricultural Robots: A Review

Journal of Field Robotics, Volume 43, Issue 5, Page 3474-3505, August 2026.
ABSTRACT Control systems for the navigation of autonomous agricultural robots—particularly those operating in uneven terrain and in the presence of static or dynamic obstacles—have advanced considerably in recent years. As conventional machinery evolves toward increasingly automated systems, the design of reliable navigation controllers has become ...
Edna Carolina Moriones Polanía, Hugo Rafacho Fernandes, Daniel Albiero, Angel Pontin Garcia   +3 more
wiley   +1 more source

Correcting negatively biased refractivity below ducts in GNSS radio occultation: an optimal estimation approach towards improving planetary boundary layer (PBL) characterization [PDF]

Atmospheric Measurement Techniques, 2017
Global Navigation Satellite System (GNSS) radio occultation (RO) measurements are promising in sensing the vertical structure of the Earth's planetary boundary layer (PBL).
K.-N. Wang, M. de la Torre Juárez, C. O. Ao, F. Xie   +3 more
doaj   +1 more source

Validation of ANCHOR Ionospheric Data Assimilation Model Using GIRO Ionosondes Within PyVALION Software

Radio Science, Volume 61, Issue 8, August 2026.
Abstract Accurate specification of the ionosphere is essential for mitigating the impacts of space weather on communication, navigation, and surveillance systems. ANCHOR is a newly developed ionospheric data assimilation (DA) model from the U.S. Naval Research Laboratory that fuses measurements from ionosondes, radio occultation, and Global Navigation ...
Victoriya V. Forsythe, Katherine A. Zawdie, Dustin Hickey, Angeline G. Burrell   +3 more
wiley   +1 more source

Assessment of GRAS Ionospheric Measurements for Ionospheric Model Assimilation

Remote Sensing, 2023
We conducted a study to assess the GNSS (Global Navigation Satellite System) Receiver for Atmospheric Sounding (GRAS) ionospheric data quality by processing Radio Occultation (RO) observations of ionospheric products.
M. M. Hoque, F. S. Prol, M. Hernandez-Pajares, R. Notarpietro, L. Yuan, G. Olivares-Pulido, V. Graffigna, A. Von Engeln, C. Marquardt   +8 more
doaj   +1 more source

Assessing GNSS Reflectometry for High‐Latitude 3D Ionospheric Imaging

Journal of Geophysical Research: Space Physics, Volume 131, Issue 8, August 2026.
Abstract This study investigates whether Global Navigation Satellite System Reflectometry (GNSS‐R) measurements from low‐Earth‐orbit (LEO) satellites can improve three‐dimensional (3D) ionospheric electron density imaging, with a focus on high‐latitude regions. Conventional ionospheric tomography is limited by sparse ground‐based receiver coverage over
Brenna Royersmith, Brian Breitsch, Jade Y. Morton   +2 more
wiley   +1 more source

Identification of ionospheric scintillation in the low-latitude African sector using a commercial CubeSat constellation

Journal of Space Weather and Space Climate
Radio occultation (RO) measurements performed by Global Navigation Satellite System (GNSS) receivers onboard low-earth orbit (LEO) satellites are commonly used for a variety of atmospheric applications, including ionospheric and space weather studies. We
Mohanty Shradha, Hoque M. Mainul, Angling Matthew J.   +2 more
doaj   +1 more source

The potential of observing atmospheric rivers with Global Navigation Satellite System (GNSS) radio occultation [PDF]

Atmospheric Measurement Techniques
Atmospheric rivers (ARs) are comparatively narrow regions in the atmosphere that are responsible for most of the horizontal transport of water vapor in the extratropics, which are responsible for many extreme precipitation events and flooding at ...
B. Rahimi, U. Foelsche, U. Foelsche
doaj   +1 more source

Processing and Validation of the STAR COSMIC-2 Temperature and Water Vapor Profiles in the Neutral Atmosphere

Remote Sensing, 2022
The global navigation satellite system (GNSS) radio occultation (RO) is becoming an essential component of National Oceanic and Atmospheric Administration (NOAA) observation systems.
Shu-peng Ho, Stanislav Kireev, Xi Shao, Xinjia Zhou, Xin Jing   +4 more
doaj   +1 more source

The 2021 volcanic eruption in La Palma Island and its impact on ionospheric scintillation as measured from GNSS reference stations, GNSS-R, and GNSS-RO

, 2022
Abstract. Ionospheric disturbances induced by seismic activity have been studied in the last years by many authors, showing an impact both before and after the occurrence of earthquakes. In this study, the ionospheric scintillation produced by the 2021 La Palma volcano eruption is analyzed.
Molina Ordóñez, Carlos, Boudriki Semlali, Badr Eddine, Hyuk, Park, Camps Carmona, Adriano José   +3 more
openaire   +3 more sources

How the 29 July 2025 M8.8 Kamchatka Earthquake Shook the Ionosphere Over Japan

Journal of Geophysical Research: Space Physics, Volume 131, Issue 7, July 2026.
Abstract This study investigates the mid‐field (∼1,100–3,800 km) ionospheric response to the 29 July 2025 Kamchatka earthquake over Japan using multi‐instrument observations, raytracing, and numerical simulations. Total electron content (TEC) observations from GPS satellite G04 and Galileo satellite E10 show a maximum TEC perturbation of ∼0.5–0.85 TECU
R. K. Barad, E. Astafyeva, S. A. Sanchez, E. A. Kherani, I. D. Ouar, C. Maréchal   +5 more
wiley   +1 more source