Results 31 to 40 of about 763,719 (165)

An ERA5‐Based Model for Estimating Tropospheric Delay and Weighted Mean Temperature Over China With Improved Spatiotemporal Resolutions

Earth and Space Science, 2019
Tropospheric delay is an important error source in Global Navigation Satellite System (GNSS) positioning and can also be used in water vapor monitoring.
Zhangyu Sun, Bao Zhang, Yibin Yao
doaj   +1 more source

Tropospheric Second-Order Horizontal Gradient Modeling for GNSS PPP

Remote Sensing, 2022
The asymmetric delay has a considerable impact on Global Navigation Satellite Systems (GNSS) Positioning, Navigation and Timing (PNT) applications. In GNSS analyses, the impacts of the asymmetric delay are commonly compensated by using the classical ...
Yaozong Zhou, Yidong Lou, Weixing Zhang, Peida Wu, Jingna Bai, Zhenyi Zhang   +5 more
doaj   +1 more source

Optimization of GPS water vapor tomography technique with radiosonde and COSMIC historical data [PDF]

Annales Geophysicae, 2016
The near-real-time high spatial resolution of atmospheric water vapor distribution is vital in numerical weather prediction. GPS tomography technique has been proved effectively for three-dimensional water vapor reconstruction.
S. Ye, P. Xia, C. Cai
doaj   +1 more source

Refinement of global gridded ray-traced Zenith tropospheric delay over Nigeria based on local GNSS network observations

Geosystems and Geoenvironment, 2023
Recent studies on the application of Zenith Tropospheric Delay (ZTD) in meteorology and geodesy have shown improved accuracy with the use of locally estimated ZTD compared to Global ZTD.
Ifechukwu Ugochukwu Nzelibe, Timothy Oluwadare Idowu   +1 more
doaj   +1 more source

Selecting ERA5 Grid Spacing for GNSS Tropospheric Parameters over China

Atmosphere
ERA5 is the fifth-generation atmospheric reanalysis from the European Centre for Medium-Range Weather Forecasts. It combines observations with a weather model to reconstruct past atmospheric conditions.
Ziyang Ding, Chao Liu, Zihan Peng, Clement Chongo, James Ngoma   +4 more
doaj   +1 more source

A New Global ZTD Forecast Model Based on Improved LSTM Neural Network

IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing
Zenith tropospheric delay (ZTD), consisting of zenith hydrostatic delay (ZHD) and zenith wet delay (ZWD), is a significant contributor to errors in precise positioning using the global navigation satellite system (GNSS) precise point positioning (PPP ...
Lin He, Yibin Yao, Chaoqian Xu, Zhang Huan, Feifei Tang, Changquan Ji, Zhuoya Liu, Wentan Wu   +7 more
doaj   +1 more source

A new vertical reduction model for enhancing the interpolation accuracy of VMF1/VMF3 tropospheric delay products [PDF]

Geoscientific Model Development
Grid-wise Vienna Mapping Functions 1 (VMF1) and Vienna Mapping Functions 3 (VMF3) tropospheric products are widely used to interpolate the a priori zenith hydrostatic delay (ZHD) and zenith wet delay (ZWD) over GNSS (Global Navigation Satellite Systems ...
P. Sun, K. Zhang, K. Zhang, D. Zhu, S. Shi, X. Liu, D. Zhao, M. Zhang, S. Wu   +8 more
doaj   +1 more source

Empirical model for mean temperature for Indian zone and estimation of precipitable water vapor from ground based GPS measurements [PDF]

Annales Geophysicae, 2007
Estimation of precipitable water (PW) in the atmosphere from ground-based Global Positioning System (GPS) essentially involves modeling the zenith hydrostatic delay (ZHD) in terms of surface Pressure (Ps) and subtracting it from the corresponding ...
C. Suresh Raju, K. Saha, B. V. Thampi, K. Parameswaran   +3 more
doaj   +1 more source

Spatio‐Temporal Variability of Topside Layers in Mars’ Dayside Ionosphere Using Near‐Simultaneous Mars Express and MAVEN Conjunctions

Journal of Geophysical Research: Planets, Volume 131, Issue 11, November 2026.
Abstract This study investigates the spatio‐temporal variability of topside ionospheric layers over the strong crustal magnetic fields and an unmagnetized region in the southern hemisphere of Mars with multipoint observations between Mars Express (MEX) and Mars Atmosphere and Volatile EvolutioN (MAVEN) very close in time and space.
Dikshita Meggi, Beatriz Sánchez‐Cano, Christopher M. Fowler, Mark Lester, Anna K. Turner, Rong Tian, Simon Joyce, Shaosui Xu, Xiaohua Fang, Olivier Witasse, Mats Holmstrom   +10 more
wiley   +1 more source

Assimilation of 5G Base Station Networks as Ultra‐Dense Atmospheric Sensors for Advancing Heavy Rainfall Prediction

Geophysical Research Letters, Volume 53, Issue 20, 28 October 2026.
Abstract The zenith total delay (ZTD) retrieved from 5G communication base stations represents a novel observation source for numerical weather prediction (NWP), leveraging the extensive global deployment of 5G infrastructure. In this study, the direct assimilation of 5G‐ZTD observations into a high‐resolution NWP system was accomplished for the first ...
Jian Yin, Xiefei Zhi, Danni Huang, Chunqing Shang, Hong Liang, Kezuan Wang   +5 more
wiley   +1 more source