Physics-Informed Hemispherical Mapping for Global Navigation Satellite System Multipath Mitigation in Mining...

Area of Science:

• Geodesy
• Satellite Navigation
• Geophysical Monitoring

Background:

• Multipath interference is a significant challenge for precise point positioning (PPP) in Global Navigation Satellite System (GNSS) based subsidence monitoring, especially in complex mining environments.
• Existing methods struggle to effectively mitigate multipath errors, limiting the accuracy of subsidence measurements.

Purpose of the Study:

• To develop and validate a novel physics-informed multipath hemispherical mapping (PI-MHM) model for multifrequency, multi-GNSS PPP.
• To enhance the accuracy and reliability of subsidence monitoring in mining areas by effectively correcting multipath effects.

Main Methods:

• The PI-MHM model integrates single-difference-to-undifferenced residual preprocessing with a multilayer perceptron to model directional multipath.
• It incorporates physical constraints such as orbital repeatability, spatial smoothness, and high-elevation attenuation as soft constraints.
• The model was validated using 11 days of multi-GNSS data from three mining-area monitoring stations (CR01, CR05, CR07).

Main Results:

• PI-MHM achieved significant mean residual root-mean-square (RMS) reduction rates of 37.1% (CR01), 38.3% (CR05), and 40.1% (CR07).
• The model outperformed existing methods including trend-surface MHM (T-MHM), congruent cells multipath central grid (C-MCG), and convolutional neural network-long short-term memory (CNN-LSTM).
• In a 1-hour three-system PPP test, mean horizontal and vertical RMS decreased from 3.56/5.66 cm to 2.31/3.44 cm, respectively, with post-convergence up-component RMS at CR07 improving from 2.72 cm to 1.99 cm.

Conclusions:

• The proposed PI-MHM model effectively mitigates multipath errors in GNSS-PPP subsidence monitoring within mining areas.
• Incorporating physical priors like repeatability, smoothness, and elevation-dependent attenuation significantly improves multipath correction performance.
• PI-MHM offers a promising solution for enhanced accuracy and reliability in challenging geodetic monitoring applications.