Results 41 to 50 of about 424 (141)

Toward an Optimal Selection of Constraints for Terrestrial Reference Frame (TRF)

Remote Sensing, 2022
Given that the observations from current space geodetic techniques do not carry all the necessary datum information to realize a Terrestrial Reference System (TRS), and each of the four space geodetic techniques has limits, for instance: Very Long ...
Shize Song, Zhongkai Zhang, Guangli Wang
doaj   +1 more source

Integration of Statistical Models and Deep Learning: A CEEMDAN‐Based Hybrid Framework for Frequency‐Domain Prediction of Polar Motion

Earth and Space Science, Volume 12, Issue 10, October 2025.
Abstract High‐precision Earth Rotation Parameter (ERP) products often experience delays that range from several days to weeks. The use of precise forecasting models can effectively compensate for the impact of such delays. Based on a systematic analysis of the forecasting capabilities of the traditional harmonic least squares fitting and autoregressive
Chen Ren, Chen Wang, Zhenhong Li, Haoran Gong, Jialiang Liu   +4 more
wiley   +1 more source

Comparison of VLBI and GNSS common view for time transfer

International Journal of Metrology and Quality Engineering, 2019
With the rapid development of optical clock, the stability and system uncertainty of optical clocks has reached a 1.0e–18 level. Optical clocks will likely constitute the next generation of time-frequency standards for redefining the SI second.
Wang Pingli, Wang Guangli, Gao Yuping, Cai Hongbing, Liu Na   +4 more
doaj   +1 more source

Estimation and Attribution of Horizontal Land Motion Measured by the Greenland GNSS Network

Journal of Geophysical Research: Solid Earth, Volume 130, Issue 9, September 2025.
Abstract Horizontal land motion, as observed by geodetic techniques such as Global Navigation Satellite Systems (GNSS), is generally dominated by tectonic plate movement. However, in regions that are currently or formerly glaciated, such as Greenland, the deformation of the solid Earth due to surface loading complicates the separation of tectonic and ...
D. Longfors Berg, S. Adhikari, J. Hassan, R. Steffen, H. Steffen, M. Willis, S. A. Khan   +6 more
wiley   +1 more source

VLBI وسیله ای برای اندازه گیری جابه جایی پوسته سطح کره زمین [PDF]

اطلاعات جغرافیایی, 2004
بیشتر از 25 سال از تاریخ توسعه و اجرا روش فضایی به نام اندازه­ گیری طول­های مبنایی با استفاده از روش تداخل امواج (Baseline Interferometry VLBI= Very Long) می­ گذرد این روش امکان اندازه ­گیری حرکات پوسته زمین را به روش غیرمعمول فراهم نموده است.
مجید مختارانی
doaj  

A Review of Machine Learning‐Based Ionospheric Spatial and Temporal Modeling

Journal of Geophysical Research: Machine Learning and Computation, Volume 2, Issue 3, September 2025.
Abstract The ionosphere introduces disturbances and errors in radio signals for satellite communication and navigation, requiring precise modeling to mitigate these effects. However, accurate ionospheric modeling faces challenges due to the complex spatio‐temporal variations caused by intricate coupling with the lower atmosphere and Earth's magnetic ...
Shuyin Mao, Manuel Hernández‐Pajares, Benedikt Soja   +2 more
wiley   +1 more source

Deep Space Network Radio Science and Ground‐Based Planetary Radar in the Next Decade

Radio Science, Volume 60, Issue 7, July 2025.
Abstract The Deep Space Network (DSN) has been a core operational element of NASA's crewed and robotic exploration of the Solar System since the early 1960s. The primary role of the DSN has been to acquire telemetry and navigation data, but over the years, its radiometric and radar capabilities have expanded to form a system for obtaining unique ...
R. S. Park, J. E. Riedel, N. Rodriguez‐Alvarez, M. Brozovic, L. A. M. Benner, P. Vergados, D. Buccino, C. S. Jacobs, L. S. Locke, S. W. Asmar, R. Castano, T. J. W. Lazio, J. Jao, C. Lee   +13 more
wiley   +1 more source

Enhanced Global Ionospheric Mapping Using Deep Ensemble Neural Networks With Uncertainty Quantification

Space Weather, Volume 23, Issue 7, July 2025.
Abstract Global ionospheric mapping is essential for ionospheric research. However, conventional approaches often struggle to accurately capture small‐scale ionospheric variations. This study proposes a deep ensemble method based on neural networks (NNs) that generates high‐accuracy global vertical total electron content (VTEC) maps along with ...
Shuyin Mao, Yuanxin Pan, Grzegorz Kłopotek, Matthias Schartner, Hana Krásná, Aletha de Witt, Benedikt Soja   +6 more
wiley   +1 more source

A Very Long Baseline Interferometry Calibrator Grid at 600 MHz for Fast Radio Transient Localizations with CHIME/FRB Outriggers

The Astrophysical Journal
The Canadian Hydrogen Intensity Mapping Experiment Fast Radio Burst (CHIME/FRB) Project has a new very long baseline interferometry (VLBI) Outrigger at the Green Bank Observatory (GBO), which forms a 3300 km baseline with CHIME operating at 400–800 MHz ...
Shion Andrew, Calvin Leung, Alexander Li, Kiyoshi W. Masui, Bridget C. Andersen, Kevin Bandura, Alice P. Curtin, Jane Kaczmarek, Adam E. Lanman, Mattias Lazda, Juan Mena-Parra, Daniele Michilli, Kenzie Nimmo, Aaron B. Pearlman, Mubdi Rahman, Vishwangi Shah, Kaitlyn Shin, Haochen Wang, (CHIME/FRB Collaboration)   +18 more
doaj   +1 more source

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