51 Result(s)
within
Tianhe **ao
Geophysics/Geodesy
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Article
Design of real-time GNSS-R software-defined receiver for coastal altimetry using GPS/BDS/QZSS signals
Global navigation satellite system reflectometry (GNSS-R) has considerable potential for monitoring sea surface height with high spatiotemporal resolution at low cost. However, because of the immaturity of ref...
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Article
A precipitation forecast model with a neural network and improved GPT3 model for Japan
Accurate monitoring of atmospheric water vapor content is essential for the early warning of extreme weather events. As known, GNSS zenith troposphere delay (GNSS_ZTD) is an indispensable data source for retri...
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Article
Analysis of the J2 relativistic effect on the performance of on-board atomic clocks
The GNSS satellite atomic clock is subjected to appreciable relativistic effects during its in-orbit operation. These effects include drift due to the gravitational redshift and time dilation due to the relati...
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Article
Inter-system biases solution strategies in multi-GNSS kinematic precise point positioning
Estimating inter-system biases (ISBs) is important in multi-constellation Global Navigation Satellite System (GNSS) processing. The present study aims to evaluate and screen out an optimal estimation strategy ...
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Article
Coastal GNSS-R phase altimetry based on the combination of L1 and L5 signals under high sea states
High-precision sea surface heights retrieved from the Global Navigation Satellite System Reflectometry (GNSS-R) measurements will be valuable in the fields of geodesy and oceanography studies. Due to the short...
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Article
Effect of the polar cap ionospheric sporadic-E layer on GNSS-based positioning: a case study at Resolute Bay, Canada, September 5, 2012
We focus on the impacts of the polar cap ionospheric sporadic-E (Es) layer that occurred at Resolute Bay, Canada, on September 5, 2012, on the quality of the Global Positioning System (GPS) observable and the ...
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Chapter and Conference Paper
A Method to Correct the Raw Doppler Observations for GNSS Velocity Determination
In the application of GNSS in the velocity determination, it is often the case that some GNSS receivers give an opposite sign for the raw Doppler observations which do not correspond to the real Doppler shift....
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Article
LEO-constellation-augmented multi-GNSS real-time PPP for rapid re-convergence in harsh environments
GNSS signals are blocked in forests, urban canyons, and indoors. Precise positioning can hardly be guaranteed in these challenging environments. A low earth orbit (LEO) constellation serving as a navigation sy...
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Article
Integrated GNSS Doppler velocity determination for GEOHALO airborne gravimetry
A gravity sensor onboard an aircraft always measures the sum of all accelerations acting on the sensor. To separate the accelerations caused by the movement of the aircraft from the gravitational accelerations...
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Article
A shipborne experiment using a dual-antenna reflectometry system for GPS/BDS code delay measurements
Global navigation satellite system-reflectometry (GNSS-R) has great potential to be a novel technique for altimetry, which can be used to derive sea surface heights (SSH). Shipborne altimetry is an important m...
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Article
Open AccessAn investigation of mass changes in the Bohai Sea observed by GRACE
The Gravity Recovery and Climate Experiment (GRACE) satellite mission has profoundly advanced our knowledge of contemporary sea level change. Owing to the coarse spatial resolution and leakage issue across the...
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Chapter and Conference Paper
Coastal GNSS-R Code Delay Altimetry Using GPS L5 Signals
In recent years, with the gradual completion of different GNSS constellations, the available L-band navigation signals have become more abundant. Not only can they be used for PNT (Positioning, Navigation, and...
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Chapter and Conference Paper
Research on Sea Surface Height Measurement Based on GNSS-IR Dual Frequency Data Fusion
It is an important application of GNSS in marine remote sensing to measure sea level by using Global Navigation Satellite System Interferometry Reflectometry (GNSS-IR), which provides a new direction for globa...
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Chapter and Conference Paper
Sound Velocity Profile Prediction Method Based on RBF Neural Network
As a marine environmental parameter, sound velocity has an important impact on sound propagation in the ocean. In the same sea area, the sound velocity profile (SVP) changes dynamically due to the influence o...
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Article
An improved prediction algorithm for Earth’s polar motion with considering the retrograde annual and semi-annual wobbles based on least squares and autoregressive model
Earth Rotation Parameters (ERP) are indispensable in the transformation between the Celestial Reference Frame and the Terrestrial Reference Frame, and significant for high-precision space navigation and positi...
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Article
Multi-GNSS precise orbit positioning for airborne gravimetry over Antarctica
Accurate position, velocity, and acceleration information are critical for airborne gravimetry. In Antarctica, there is a sparse distribution of IGS stations, and the rough terrain makes it impractical to set ...
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Article
Comparing satellite orbit determination by batch processing and extended Kalman filtering using inter-satellite link measurements of the next-generation BeiDou satellites
The next-generation BeiDou satellites are equipped with inter-satellite link (ISL) payloads to realize the ability of autonomous navigation (Auto-Nav). We focus on the application of batch processing and exten...
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Chapter and Conference Paper
Multi-GNSS Kinematic Relative Positioning of Multiple Base Stations and Its Application in Deformation Monitoring
The traditional single base station GNSS deformation monitoring system is greatly influenced by the base station stability and data quality. In order to improve the accuracy and reliability of monitoring syste...
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Chapter and Conference Paper
Accuracy Assessment and Improvement of GNSS Precise Point Positioning Under Ionospheric Scintillation
We focus on the accuracy analysis and improvement of multi-GNSS precise point positioning (PPP) during ionospheric scintillation. By using the observation data from Hong Kong Satellite Positioning Reference St...
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Article
Adaptive Kalman filter based on variance component estimation for the prediction of ionospheric delay in aiding the cycle slip repair of GNSS triple-frequency signals
In order to incorporate the time smoothness of ionospheric delay to aid the cycle slip detection, an adaptive Kalman filter is developed based on variance component estimation. The correlations between measure...
