Results 71 to 80 of about 200,933 (218)

Impact of Two Radio Occultation Constellations on Numerical Weather Prediction: Polar‐Orbits Only and Mixed Polar‐Equatorial Orbits

open access: yesEarth and Space Science, Volume 13, Issue 10, October 2026.
Abstract This study explores the relative impact of two orbital configurations for Global Navigation Satellite System radio occultation (RO) observations in numerical weather prediction using observing system simulation experiments (OSSE). Three experiments are carried out: a Control experiment with no RO observations and two experiments with 14,000 RO
Nikki C. Privé   +6 more
wiley   +1 more source

Global Ionospheric TEC Forecasting Driven by a Unified Physical Index System via the Spectral Whitening Method

open access: yesSpace Weather, Volume 24, Issue 10, October 2026.
Abstract Accurate forecasting of global ionospheric total electron content (TEC) is important for Global Navigation Satellite Systems (GNSS) performance and satellite communications. This study proposes a driver framework based on the spectral whitening method (SWM). We combine a new high‐latitude geomagnetic disturbance index with previously developed
Zhou Chen   +9 more
wiley   +1 more source

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

open access: yesSensors, 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   +4 more
doaj   +1 more source

Physics‐Based Ensemble of Models for F2 Peak Parameters of the Ionosphere: Comparison With COSMIC‐2 Measurements

open access: yesSpace Weather, Volume 24, Issue 10, October 2026.
Abstract Space weather events can significantly alter the ionospheric electron density, affecting signal transmission and navigation accuracy in satellite‐based systems. Consequently, there is an urgent need for reliable forecasting of the Thermosphere‐Ionosphere (TI) system.
J. Pereira   +5 more
wiley   +1 more source

GNSS Satellite Orbit Validation Using Satellite Laser Ranging [PDF]

open access: yes, 2013
With a total of four new regional and global navigation sa tellite systems that have launched first satellites or even started an operational serv ice, the GNSS landscape has experienced major changes in recent years.
Steigenberger, Peter   +2 more
core  

Quantifying Groundwater–Surface Water Exchange on a River Island: A Comparative Analysis of Direct and Indirect Methods

open access: yesWater Resources Research, Volume 62, Issue 10, October 2026.
Abstract Groundwater–surface water exchange is a key hydrological process that governs river water quality and aquatic ecosystems. However, the quantification of such exchange remains uncertain, especially within river island aquifers where exchange processes are highly heterogeneous.
Nayeon Ki   +6 more
wiley   +1 more source

Assessment of Commercial GNSS Radio Occultation Performance from PlanetiQ Mission

open access: yesRemote Sensing
Global Navigation Satellite System (GNSS) radio occultation (RO) provides valuable 3-D atmospheric profiles with all-weather, all the time and high accuracy. However, GNSS RO mission data are still limited for global coverage.
Mohamed Zhran   +4 more
doaj   +1 more source

Seeking Optimal GNSS Radio Occultation Constellations Using Evolutionary Algorithms

open access: yesRemote 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   +4 more
doaj   +1 more source

Assimilating GNSS Airborne Radio Occultation Bending Angles With MPAS–JEDI During a Sequence of Atmospheric Rivers

open access: yesJournal of Advances in Modeling Earth Systems, Volume 18, Issue 9, September 2026.
Abstract Global Navigation Satellite System (GNSS) airborne radio occultation (ARO) observations, collected during Atmospheric River Reconnaissance (AR Recon) campaigns, enhance AR sampling beyond traditional dropsondes. Assimilating ARO bending angles requires a forward operator accounting for ARO geometry and proper integration in a data assimilation
Ivette Hernández Baños   +5 more
wiley   +1 more source

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

open access: yesAtmospheric 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   +9 more
openaire   +4 more sources

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