Application of Wavelet Filtering for continuous GNSS signals and comparison with Kalman Filtering

- Authors: Khanh Quoc Pham
Affiliations:
Hanoi University of Mining and Geology, Hanoi, Vietnam
- *Corresponding:This email address is being protected from spambots. You need JavaScript enabled to view it.
- Keywords: Continuous GNSS, ENH, Multipath noise. Kalman, Wavelet.
- Received: 17th-Dec-2025
- Revised: 1st-Apr-2026
- Accepted: 21st-Apr-2026
- Online: 1st-June-2026
- Section: Geomatics and Land Administration
Abstract:
Wavelet filtering is now effectively applied in many fields such as denoising audio signals, medical signals, GNSS; filtering and analyzing biological signals… thanks to its ability to separate noise, preserve signal characteristics, and handle both time and frequency domains well. In this study, we investigate Wavelet filtering for continuous GNSS data (ENH coordinate series) collected in Vietnam, with the aim of reducing GNSS signal noise to improve the accuracy of continuous GNSS measurements for monitoring structural displacement. The filtering results using Daubechies-4 Wavelet (db4) show that this method can be fully utilized for GNSS data filtering. Accuracy indicators such as standard deviation, root mean square error, and mean absolute error decreased by a maximum of 12.58% and a minimum of 1.07%. Compared to Kalman filtering in terms of noise reduction and stability of the filtered data series, Wavelet-db4 is more effective in smoothing signals after filtering but less effective than Kalman filtering in prediction capability. Specifically, the standard deviation of Wavelet-db4 is 9.9% lower, and the root mean square error is 9.5% lower than Kalman filtering; mean absolute error is similar, while data dispersion after filtering is 3.4% lower with Kalman. Therefore, to achieve better results when filtering continuous GNSS data, the two filtering methods can be combined.
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