Results 61 to 70 of about 1,084 (164)

Estimating the impact of Global Navigation Satellite System horizontal delay gradients in variational data assimilation [PDF]

, 2018
We developed operators to assimilate Global Navigation Satellite System (GNSS) Zenith Total Delays (ZTDs) and horizontal delay gradients into a numerical weather model. In this study we experiment with refractivity fields derived from the Global Forecast
Dick, Galina, Douša, Jan, Kačmařík, Michal, Václavovic, Pavel, Wickert, Jens, Zus, Florian   +5 more
core   +2 more sources

Optimizing PPP Performance by Incorporating ZWD Constraints Derived From Data Assimilation

Earth and Space Science, Volume 12, Issue 8, August 2025.
Abstract One of the primary error sources limiting the performance of the Precise Point Positioning (PPP) technique is the atmospheric wet delay, caused by the presence of water vapor in the lower atmosphere. Accurately representing this parameter is crucial for improving the initialization and accuracy of satellite‐based positioning techniques ...
Masoud Dehvari, Saeed Farzaneh, Ehsan Forootan   +2 more
wiley   +1 more source

Impact of a high density GPS network on the operational forecast [PDF]

Advances in Geosciences, 2005
Global Positioning System Zenith Total Delay (GPS ZTD) can provide information about the water vapour in atmosphere. Its assimilation into the analysis used to initialize a model can then improve the weather forecast, giving the right amount of moisture ...
C. Faccani, R. Ferretti, R. Ferretti, R. Pacione, T. Paolucci, F. Vespe, L. Cucurull   +6 more
doaj  

Long-term monitoring of geodynamic surface deformation using SAR interferometry [PDF]

, 2014
Thesis (Ph.D.) University of Alaska Fairbanks, 2014Synthetic Aperture Radar Interferometry (InSAR) is a powerful tool to measure surface deformation and is well suited for surveying active volcanoes using historical and existing satellites.
Gong, Wenyu, 龚文瑜
core  

Correcting Non‐Tidal Atmospheric and Oceanic Loading Displacements at the Observation, Normal Equation, and Parameter Levels in GNSS Data Analysis

Journal of Geophysical Research: Solid Earth, Volume 130, Issue 6, June 2025.
Abstract Non‐tidal loading (NTL) introduces surface deformation on the Earth and increases the variability in coordinates measured by space geodetic techniques. Correcting NTL displacements in Global Navigation Satellite Systems (GNSS) analysis has been discussed extensively, commonly at the parameter level.
Jungang Wang, Kyriakos Balidakis, Henryk Dobslaw, Benjamin Männel, Maorong Ge, Robert Heinkelmann, Harald Schuh   +6 more
wiley   +1 more source

A Novel Enhancement of the MIMIC Remote Sensing Water Vapor Product and Its Application in GNSS Positioning

IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing
Tropospheric delay plays a crucial role in global navigation satellite systems (GNSS) positioning, climate monitoring, and weather forecasting. In particular, in high-precision GNSS applications such as precise point positioning (PPP), prior tropospheric
Ranran Jia, Yan Xu, Nan Jiang, Zeqi Li, Tianhe Xu, Harald Schuh   +5 more
doaj   +1 more source

Benefits of GNSS Local Observations Compared to Global Weather‐Based Models for InSAR Tropospheric Corrections Over Tropical Volcanoes: Case Studies of Piton De La Fournaise and Merapi

Journal of Geophysical Research: Solid Earth, Volume 130, Issue 4, April 2025.
Abstract From repeat‐pass interferometry, tropospheric signals often prevent the detection of ground deformation signals. In recent years, tropospheric corrections derived from global weather‐based models have been implemented in several InSAR processing chains.
F. Albino, S. Gremion, V. Pinel, P. Bouygues, A. Peltier, F. Beauducel, J.‐L. Froger, Agus Budi Santoso   +7 more
wiley   +1 more source

GPS Zenith Total Delays and Precipitable Water in comparison with special meteorological observations in Verona (Italy)during MAP-SOP

Annals of Geophysics, 2002
Continuous meteorological examination of the Pre-Alpine zones in Northern Italy (Po Valley)is important for determination of atmospheric water cycles connected with floods and rainfalls.During a special meteorological observing period (MAP-SOP ...
S. Corradini, R. Santangelo, S. Pugnaghi, L. Lombroso, P. Frontero, S. Fazlagic, M. Boccolari, S. Teggi   +7 more
doaj   +1 more source

Asymmetricity of ground-based GPS slant delay data [PDF]

, 2007
International audienceThe ground-based measurements of the Global Positioning System (GPS) allow estimation of the tropospheric delay along the slanted signal paths through the atmosphere.
Eresmaa, R., Järvinen, H., Niemelä, S., Salonen, K.   +3 more
core   +1 more source

A Global Assessment of Diurnal Discontinuities in ERA5 Tropospheric Zenith Total Delays Using 10 Years of GNSS Data

Geophysical Research Letters, Volume 52, Issue 5, 16 March 2025.
Abstract The diurnal cycle of tropospheric Zenith Total Delays (ZTD) is critical for refining tropospheric models and understanding key geophysical and atmospheric processes. The fifth European Centre for Medium‐Range Weather Forecasts reanalysis ERA5, with its unique 1‐hr temporal resolution, provides valuable data for these purposes.
Peng Yuan, Geoffrey Blewitt, Corné Kreemer, Weiping Jiang, Tianjun Liu, Linyu He, Qiang Shan, Kyriakos Balidakis, Harald Schuh, Jens Wickert, Zhiguo Deng   +10 more
wiley   +1 more source