Results 21 to 30 of about 1,220 (193)

Regional zenith tropospheric delay prediction using DBO-optimized CNN-LSTM with multihead attention [PDF]

Scientific Reports
Zenith Total Delay (ZTD) is integral to applications such as atmospheric water vapor inversion and precise positioning in the Global Navigation Satellite System (GNSS).
Ruixue Yang, Xu Yang, Shicheng Xie, Xuexiang Yu   +3 more
doaj   +2 more sources

Regional Zenith Tropospheric Delay Modeling Based on Least Squares Support Vector Machine Using GNSS and ERA5 Data

Remote Sensing, 2021
The meteorological reanalysis data has been widely applied to derive zenith tropospheric delay (ZTD) with a high spatial and temporal resolution. With the rapid development of artificial intelligence, machine learning also begins as a high-efficiency ...
Song Li, Tianhe Xu, Nan Jiang, Honglei Yang, Shuaimin Wang, Zhen Zhang   +5 more
doaj   +2 more sources

Assessment of ZTD Derived from COSMIC Occultation Data with ECWMF, Radiosondes, and GNSS. [PDF]

Sensors (Basel), 2022
Global Navigation Satellite System (GNSS) signals generate slant tropospheric delays when they pass through the atmosphere, which is recognized as the main source of error in many spatial geodetic applications. The zenith tropospheric delay (ZTD) derived from radio occultation data is of great significance to atmospheric research and meteorology and ...
Fu N, Jiang M, Li F, Guo P, Hou C, Wu M, Wu J, Wang Z, Kan L.   +8 more
europepmc   +4 more sources

A Novel Method for Monitoring Tropical Cyclones’ Movement Using GNSS Zenith Tropospheric Delay

Remote Sensing, 2023
Precipitable water vapor (PWV) is an important meteorological factor for predicting extreme weather events such as tropical cyclones, which can be obtained from zenith tropospheric delay (ZTD) by using a conversion.
Dajun Lian, Qimin He, Li Li, Kefei Zhang, Erjiang Fu, Guangyan Li, Rui Wang, Biqing Gao, Kangming Song   +8 more
doaj   +3 more sources

Variational Bias Correction of GNSS ZTD in the HARMONIE Modeling System [PDF]

Journal of Applied Meteorology and Climatology, 2016
AbstractTo fill the gap in the observation system for humidity, the HIRLAM–ALADIN Research on Mesoscale Operational NWP in Euromed (HARMONIE) limited-area high-resolution kilometer-scale model has been prepared for assimilation of Global Navigation Satellite System (GNSS) zenith total delay (ZTD) observations. The observation-processing system includes
Sánchez Arriola, Jana, Lindskog, Magnus, Thorsteinsson, Sigurdur, Bojarova, Jelena   +3 more
openaire   +3 more sources

TransXLT: A novel ZTD prediction method with SASR-based data reconstruction. [PDF]

iScience
Traditional Zenith Tropospheric Delay (ZTD) models often face difficulties in maintaining prediction accuracy under complex meteorological conditions and data loss. To address this, we propose the transformer-xLSTM (TransXLT) model, which integrates spatial-temporal information from global navigation satellite system (GNSS) stations, ERA5 (global ...
Shicheng Xie, Yu X, Yuan J, Yang X, Zhu M, Han Y, Wei M, Guo Z.   +7 more
europepmc   +4 more sources

Development of a ZTD Vertical Profile Model Considering the Spatiotemporal Variation of Height Scale Factor with Different Reanalysis Products in China

Atmosphere, 2022
Tropospheric delay is one of the key factors that may affect high-precision satellite navigation and positioning and water vapor retrieval performance.
Xin Wang, Ge Zhu, Liangke Huang, Haoyu Wang, Yunzhen Yang, Junyu Li, Ling Huang, Lv Zhou, Lilong Liu   +8 more
doaj   +2 more sources

Real-time retrieval of high-precision ZTD maps using GNSS observation

Geodesy and Geodynamics
Zenith Tropospheric Delay (ZTD) is an important factor that restricts the high-precision positioning of global navigation satellite system (GNSS), and it is of great significance in establishing a real-time and high-precision ZTD model. However, existing
Qingzhi Zhao, Wei Wang, Jinfang Yin, Kan Wu, Lv Zhou, Yibin Yao, Pengcheng Wang, Jing Su, Xiaocheng Wang, Han Wang, Jia Bao, Yumeng Hu, Zhou Zhuo, Yuting Gao   +13 more
doaj   +2 more sources

A Tropospheric Zenith Delay Forecasting Model Based on a Long Short-Term Memory Neural Network and Its Impact on Precise Point Positioning

Remote Sensing, 2022
Global navigation satellite system (GNSS) signals are affected by refraction when traveling through the troposphere, which result in tropospheric delay. Generally, the tropospheric delay is estimated as an unknown parameter in GNSS data processing.
Huan Zhang, Yibin Yao, Mingxian Hu, Chaoqian Xu, Xiaoning Su, Defu Che, Wenjie Peng   +6 more
doaj   +2 more sources

Evaluation of Zenith Tropospheric Delay Derived from ERA5 Data over China Using GNSS Observations

Remote Sensing, 2020
The latest reanalysis of the European Center for Medium-Range Weather Forecasts (ECMWF), ERA5, can provide atmospheric data for calculating Zenith Tropospheric Delay (ZTD) with hourly temporal resolution, which is a key factor in Global Navigation ...
Chunhua Jiang, Tianhe Xu, Shuaimin Wang, Wenfeng Nie, Zhangzhen Sun   +4 more
doaj   +2 more sources