Algorithm for Suppressing Sleeper Interferences in Railway Subgrade GPR Signals

TLDR: In this article, the resampled multiple channels of records are translated, superposed and reaveraged by one time and multiple times of sleeper-to-sleeper periods to from the time space filter screen holding the interference information of sleepers.

Abstract: When the ground-penetrating radar(GPR) is used in exploration of railway subgrades,its records are severely interfered in data processing by direct-coupled waves from antennas,strong rail reflection,and diffraction and multiple waves caused by sleepers.Sleeper interference in raw records possesses the feature of space-time periodic distribution.In this paper,the resampled multiple channels of records are translated,superposed and reaveraged by one time and multiple times of sleeper-to-sleeper periods to from the time space filter screen holding the interference information of sleepers.It is seen that the time space filter screen can be used to well suppress the diffraction and multiple waves caused by sleepers and direct-coupled waves and strong rail reflections can also be suppressed at the same time.Numerical simulation and measured data processing show the time space filter screen algorithm has obvious effects in improving the SNR and resolution capability of abnormalities of the GPR records.