Results 1 to 10 of about 1,516 (192)

A Regional Zenith Tropospheric Delay (ZTD) Model Based on GPT3 and ANN [PDF]

Remote Sensing, 2021
The delays of radio signals transmitted by global navigation satellite system (GNSS) satellites and induced by neutral atmosphere, which are usually represented by zenith tropospheric delay (ZTD), are required as critical information both for GNSS ...
Fei Yang, Jiming Guo, Chaoyang Zhang, Yitao Li, Jun Li   +4 more
doaj   +3 more sources

High-Precision ZTD Model of Altitude-Related Correction

IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing, 2023
Zenith tropospheric delay (ZTD) is one of the main error sources in space geodesy. The existing regional or global models, such as Global Pressure and Temperature 3 (GPT3), Global Tropospheric model, Global Hopfield, and Shanghai Astronomical observatory
Chaoqian Xu, Qingzhi Zhao, Yibin Yao
exaly   +5 more sources

Evaluation of the ZWD/ZTD Values Derived from MERRA-2 Global Reanalysis Products Using GNSS Observations and Radiosonde Data [PDF]

Sensors, 2020
Tropospheric delay is one of the main errors affecting high-precision positioning and navigation and is a key parameter of water vapor detection in the Global Navigation Satellite System (GNSS).
Liangke Huang, Lijie Guo, Lilong Liu, Hua Chen, Jun Chen, Shaofeng Xie   +5 more
doaj   +3 more sources

A Refined Spatiotemporal ZTD Model of the Chinese Region Based on ERA and GNSS Data

Remote Sensing
Empirical tropospheric models can improve the performance of GNSS precise point positioning (PPP) by providing a priori zenith tropospheric delay (ZTD) information.
Yongzhao Fan, Zhimin Sha
exaly   +4 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

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

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

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

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

A New Four-Layer Inverse Scale Height Grid Model of China for Zenith Tropospheric Delay Correction

IEEE Access, 2020
To reduce the convergence time in the real-time precise point positioning (PPP), the zenith tropospheric delay (ZTD) needs to be modeled with high accuracy and sent to the users to be introduced as a priori value. Because of the height difference between
Shaotian Zhang, Xiaoming Wang, Zishen Li, Cong Qiu, Jinglei Zhang, Haobo Li, Li Li   +6 more
doaj   +1 more source