Improving Passive Seismic Surface Wave Dispersion Measurement Deteriorated by Strong Fixed-Frequency Interference in the Industry Environment

Summary Passive seismic surface wave method with ambient noise is now widely used for imaging near-surface shear-wave velocity (Vs) structure. However, in some industry environment with strong fixed-frequency interference (FFI) related to mechanical operations, traditional ambient noise data processing flow fails to produce satisfactory surface wave dispersion spectrum. In this study, we propose a new data processing workflow that incorporates data filtering based on singular value decomposition (SVD), seismic interferometry and coherence-based virtual shot gather (VSG) enhancing to effectively address the issue caused by FFI. We have validated our workflow on a synthetic test, demonstrating that it produces improved VSG and higher-quality surface-wave dispersion spectrum compared to traditional seismic interferometry processing flow. The proposed workflow is also applied to a field dataset with two arrays deployed in a coal mining environment, where strong FFI is generated by the ventilation shafts. The field data application shows that the proposed workflow has effectively mitigated the effect of the FFI and produced clearer and more continuous fundamental mode dispersion energy. Therefore, our proposed workflow is effective for conducting passive seismic surveys in the increasingly complex scenarios affected by the FFI.