Research on Application of Improved S Transform in High Frequency GNSS Data Processing Results during Earthquake
【摘要】：The high-frequency GNSS data at the time of earthquake was obtained by dynamic single-epoch positioning solution, and the GNSS displacement results were obtained. However, the seismic-time GNSS displacement result after dynamic single-epoch solution contains a lot of noise. It has a great impact on the analysis and research of the displacement during the earthquake, in order to minimize the noise impact in the results and improve the accuracy of dynamic positioning. Traditionally, the S transform denoising method is used to denoise the processing results, but the denoising effect is affected because its time resolution is limited.This paper improves the S-transform method and improves its time-frequency resolution. The principle of S-transform and improved S-transform is introduced. The improved S-transform is used to denoise the high-frequency GNSS single-epoch dynamic positioning results after earthquake processing by GAMIT/TRACK, which greatly removes the noise of displacement results and improves The analysis and research of the dynamic positioning accuracy and the high-frequency GNSS displacement results during the earthquake are made to more accurately determine the time when the GNSS seismic wave arrives at the observation station. Finally, based on the characteristics of high-frequency GNSS acquisition of seismic instantaneous deformation information, this paper proposes an improved Stransform method combined with a trend term denoising method, which can minimize the effect of positioning errors of long-period low-frequency displacement signals, which is more conducive to the in-depth study of GNSS Seismology.