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Article
The proposed plan of geodetic VLBI in India serving national and global objectives
Project “Saptarshi” was initiated by the National Centre for Geodesy, Indian Institute of Technology Kanpur to set up the modern space geodetic infrastructure in the country. This project primarily focuses on ...
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Article
Open AccessThe Impact of Surface Loading on GNSS Stations in Africa
The movement of the Earth's surface mass, including the atmosphere and oceans, as well as hydrology and glacier melting, causes the redistribution of surface loads, deformation of the solid Earth, and fluctuat...
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Article
Open AccessAssessment of length-of-day and universal time predictions based on the results of the Second Earth Orientation Parameters Prediction Comparison Campaign
Predicting Earth Orientation Parameters (EOP) is crucial for precise positioning and navigation both on the Earth’s surface and in space. In recent years, many approaches have been developed to forecast EOP, i...
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Article
Open AccessAn effective automatic processing engine for improving the multi-GNSS constellation precise orbit prediction
Orbit prediction (OP) recently tends to be a very crucial step for supporting real-time GNSS orbit services due to the dynamic stability of navigation satellite orbits. The OP performance depends on the length...
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Article
Open AccessUtilizing least squares variance component estimation to combine multi-GNSS clock offsets
The International GNSS Service (IGS) provides combined satellite and station clock products, which are generated from the individual clock solutions produced by the analysis centers (ACs). Combinations for GPS...
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Chapter and Conference Paper
Application of Probability and Statistics on GNSS Data to Analyze TEC Anomalies Generated by Earthquakes
Ionospheric disturbances are associated with the propagation of seismic waves generated by earthquakes. We analyze total electron content (TEC) fluctuations from Global Navigation Satellite Systems (GNSS) data...
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Chapter and Conference Paper
K-Fold Cross-Validation: An Effective Hyperparameter Tuning Technique in Machine Learning on GNSS Time Series for Movement Forecast
In deformation analysis, irregularly spaced data, extreme values, and anomalies in time series can lead to misleading simulations for forecast models, such as overfitting and underfitting. Therefore, K-fold cr...
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Article
Open AccessIdentifying Neotectonic Motions in Germany Using Discontinuity-corrected GNSS Data
The crustal motions throughout Germany have not yet been fully understood because the research scope of previous studies often focuses only on some active grabens. Thus, we investigate it in detail to identify...
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Article
Open AccessMulti-GNSS ultra-rapid orbit determination through epoch-parallel processing
High-precision Global Navigation Satellite Systems (GNSS) orbits are critical for real-time clock estimation and precise positioning service; however, the prediction error grows gradually with the increasing p...
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Chapter
Correcting Non-Tidal Surface Loading in GNSS repro3 and Comparison with ITRF2020
Time-dependent mass variations lead to significant and systematic load-induced deformations of the Earth’s crust, impacting space geodetic techniques. Using the ESMGFZ loading models, the impact on the recent ...
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Chapter
Assessing the Potential of VLBI Transmitters on Next Generation GNSS Satellites for Geodetic Products
The next-generation Global Navigation Satellite Systems (NextGNSS) satellites are planned to be equipped with inter-satellite links and ultra-stable clocks as well as a dedicated Very Long Baseline Interferome...
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Article
Open AccessAdapting empirical solar radiation pressure model for BDS-3 medium Earth orbit satellites
For the precise orbit determination (POD) of global navigation satellite systems (GNSS) constellation, it is very difficult to precisely model the solar radiation pressure (SRP) force acting on GNSS satellites...
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Article
Open AccessMulti-GNSS precise point positioning with predicted orbits and clocks
Global Navigation Satellite Systems (GNSS) Real-time Precise Point Positioning (RT-PPP) strongly relies on the precise satellite orbits and clocks, especially the latter requires high update rate, e.g., five s...
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Article
Open AccessA new large-area hierarchical PPP-RTK service strategy
Introducing precise atmosphere information into precise point positioning enables rapid ambiguity resolution and introduces a significant accuracy improvement. However, it can only be implemented in regions wi...
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Chapter
Almost-Instantaneous PPP-RTK Without Atmospheric Corrections
Ambiguity resolution enabled precise point positioning (PPP-RTK) can provide fast, potentially even instantaneous, centimeter-level positioning results, given that the phase ambiguities are correctly resolved....
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Article
Open AccessFavorable locations for new VGOS antennas in India depending on the assessment of geodetic parameters and environmental factors
VLBI simulation studies are carried out to investigate the impact of any proposed station or strategy on the geodetic parameters, such as Earth Orientation Parameters (EOP) and Terrestrial Reference Frame (TRF...
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Article
Open AccessGENESIS: co-location of geodetic techniques in space
Improving and homogenizing time and space reference systems on Earth and, more specifically, realizing the Terrestrial Reference Frame (TRF) with an accuracy of 1 mm and a long-term stability of 0.1 mm/year ar...
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Chapter and Conference Paper
Selection of Optimal Mathematical Models for Simulating and Forecasting Vertical Movements
Deformation monitoring is increasingly concerned, especially for large-scale constructions or areas with a high risk of landslides and unstable Earth’s crust. The important purpose of deformation monitoring is...
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Chapter and Conference Paper
An Experimental Combination of IGS repro3 Campaign’s Orbit Products Using a Variance Component Estimation Strategy
Over the past years, the International GNSS Service (IGS) has put efforts into reprocessing campaigns, reanalyzing the entire data collected by the IGS network since 1994. Using state-of-the-art models and sof...
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Chapter and Conference Paper
Determination of a GNSS-Based Velocity Field of the African Continent
GNSS-based velocity fields are a key tool to assess the boundaries around major deforming areas, to explain the main patterns of surface motion and deformation, to analytically review existing kinematics model...
