Journal of Xi'an Jiaotong University

Abstract£ºFocusing on the problem that filtering method used in vertical seismic profile (VSP)data processing is not referred to the ambient noise£¬ a wavelet shrinkage scheme which utilizes the statistical law of ambient noise is proposed£® Based on the hypothesis that the ambient noise is statistically stationary£¬ firstly the correlation between ambient noise and real data after the first seismic arrivals is estimated£¬ when the correlation is small£¬ the statistics of stationary noise can be derived from the data before the first seismic arrivals; then stochastic noise can be attenuated in wavelet domain using a threshold estimated by the statistics of stationary noise; and finally high fidelity VSP data is obtained£® The
smulation results of the syntheticaly seismic records and real data demonstrate that the signalª²noiseª²ratio of the proposed method is about 2 dB higher than that of filtering method£®The algorithm proposed can exhibit timeª²variant characteristic of seismic signal more sufficiently, and the cophase axis of the profile is more distinct after processing£®
Keywords£ºambient noise£»vertical seismic profile data£»wavelet domain£»stochastic noise