Results 11 to 20 of about 525 (158)

Global, spatially explicit modelling of zenith wet delay with XGBoost

Journal of Geodesy
AbstractRadio signals transmitted by Global Navigation Satellite System (GNSS) satellites experience tropospheric delays. While the hydrostatic part, referred to as zenith hydrostatic delay (ZHD) when mapped to the zenith direction, can be analytically modelled with sufficient accuracy, the wet part, referred to as zenith wet delay (ZWD), is much more ...
Matthias Schartner, Florian Zus, Linda See   +2 more
exaly   +5 more sources

Statistical significance of trends in Zenith Wet Delay from re-processed GPS solutions [PDF]

GPS Solutions, 2018
Long series of Zenith Wet Delay (ZWD) obtained as part of a homogeneous re-processing of Global Positioning System solutions constitute a reliable set of data to be assimilated into climate models. The correct stochastic properties, i.e. the noise model of these data, have to be identified to assess the real value of ZWD trend uncertainties since ...
Anna Klos, Janusz Bogusz, Addisu Hunegnaw   +2 more
exaly   +3 more sources

Three‐Year Characterization of Boundary Layer Dynamics From GNSS Zenith Wet Delay Spectral Analysis

Atmospheric Science Letters
Continuous monitoring of boundary layer turbulence remains a challenge due to sparse conventional instrumentation. Here we suggest that spectral analysis of Global Navigation Satellite System (GNSS) zenith wet delay (ZWD) fluctuations yields physically ...
Gaël Kermarrec, Xavier Calbet, Zhiguo Deng   +2 more
doaj   +2 more sources

GNSS Data Processing and Validation of the Altimeter Zenith Wet Delay around the Wanshan Calibration Site

Remote Sensing, 2022
The Wanshan calibration site (WSCS) is the first in-situ field for calibration and validation (Cal/Val) of HY-2 satellite series in China. It was built in December, 2018 and began business operation in 2020.
Wanlin Zhai, Jianhua Zhu, Mingsen Lin, Chaofei Ma, Chuntao Chen, Xiaoqi Huang, Yufei Zhang, Wu Zhou, He Wang, Longhao Yan   +9 more
doaj   +2 more sources

Improving GNSS Zenith Wet Delay Interpolation by Utilizing Tropospheric Gradients: Experiments with a Dense Station Network in Central Europe in the Warm Season

Remote Sensing, 2019
The Benchmark data set collected within the European COST Action ES1206 has aimed to support the development and validation of advanced Global Navigation Satellite System (GNSS) tropospheric products, in particular high-resolution zenith delays and ...
Florian Zus, Jan Douša, Michal Kačmařík, Pavel Václavovic, Kyriakos Balidakis, Galina Dick, Jens Wickert   +6 more
doaj   +3 more sources

Global zenith wet delay modeling with surface meteorological data and machine learning

GPS Solutions
AbstractThe tropospheric delay is a major error source for space geodetic techniques, and the performance of its modeling is significantly limited due to the high spatiotemporal variability of the moisture in the lower atmosphere. In this study, global modeling of the tropospheric zenith wet delay (ZWD) was realized based on surface meteorological data
Linguo Yuan, Johannes Bohm, Weber Robert   +2 more
exaly   +2 more sources

A Self-Supervised Uncertainty-Hybrid Machine Learning Approach for Modeling Tropospheric Zenith Wet Delay

IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing
Zenith wet delay (ZWD) is one of the major sources of errors in the Global Navigation Satellite System (GNSS) positioning. Existing machine learning (ML) based ZWD models have limitations in their generalization capabilities and in modeling the high ...
Mohamed H. Sharouda, Weixing Zhang, Zhixiang Mo, Mohamed M. Elisy, Hongxing Sun, Mohamed Hosny, Yidong Lou   +6 more
doaj   +2 more sources

Using GNSS Observations for Tropospheric Delay Prediction Using Artificial Intelligence [PDF]

Port Said Engineering Research Journal, 2023
GNSS technology holds significant importance across wide applications, ranging from mapping, surveying, and precise timekeeping to ship navigation. Its operational principle hinges on the accurate measurement of signal travel time, which is crucial for ...
Ahmed Sedeek
doaj   +1 more source

A Hybrid Deep Learning Algorithm for Tropospheric Zenith Wet Delay Modeling with the Spatiotemporal Variation Considered

Atmosphere
The tropospheric Zenith Wet Delay (ZWD) is one of the primary sources of error in Global Navigation Satellite Systems (GNSS). Precise ZWD modeling is essential for GNSS positioning and Precipitable Water Vapor (PWV) retrieval.
Yin Wu, Lu Huang, Wei Feng, Su Tian
doaj   +2 more sources

Impact of Tropospheric Mismodelling in GNSS Precise Point Positioning: A Simulation Study Utilizing Ray-Traced Tropospheric Delays from a High-Resolution NWM

Remote Sensing, 2021
In GNSS analysis, the tropospheric delay is parameterized by applying mapping functions (MFs), zenith delays, and tropospheric gradients. Thereby, the wet and hydrostatic MF are derived under the assumption of a spherically layered atmosphere.
Florian Zus, Kyriakos Balidakis, Galina Dick, Karina Wilgan, Jens Wickert   +4 more
doaj   +1 more source