关键词: 地震勘探, 时频分析, 面波压制, TT变换, S变换

Abstract:

In seismic exploration, surface waves have lower frequency than effective signals, and often needs to be suppressed to enhance effective seismic waves. TT transform (time-time transform) has very good frequency gathering property and can concentrate higher frequencies more strongly around diagonal positions in TT field. The surface wave can be suppressed by extracting the diagonal elements of TT spectrum. Compared with the traditional high-pass filter method, processing results by TT method about physical model and real seismic data shows that TT transform is the extending of S transform and has a close relation with S transform. It is invertible and has good frequency gathered ability. TT transform shows good effect in the suppression of surface wave, however，it loses some low frequency effective signals and retains parts of the high frequency interference waves during extracting high-frequency,and suppressing low-frequency, which is the shortage of TT transform in signal analysis. Therefore, TT transform and S transform should be combined in practical applications to avoid some mistakes of interpretation.

Key words: seismic prospecting, time-frequency analysis, surface wave suppression, time-time transform, S transform