摘要
声波全波列中反射纵波一般位于滑行纵波与滑行横波之间,幅度比较小,常被其他模式波淹没,难于提取。小波变换具有在时间域和频率域对信号进行局部化的特点,在声波信号处理中有着广泛的应用前景。利用双树复小波对声波全波进行多尺度分解,在合适的尺度上重构波形,达到压制高能量信号、增强反射纵波的目的。并充分利用小波变换保留时间域的特性,将慢度时间相关法与多尺度方法相结合,对重构波形求取慢度-时间相关图,以此确定反射纵波的时间区域,切除其他与反射纵波频率接近的模式波,对反射纵波的提取得到了较好的效果。
The compressional wave （PP） is usually between P wave and S-wave during the full wave. Because of the smaller amplitude, PP wave is usually covered by other mode waves, and it is difficult to extract PP wave. The wavelet transform can result in localization for the signal in the time domain and in the frequency domain, so it has a broad prospect in the acoustic information processing. We select the Dual Tree Complex Wavelet Transform （DT-CWT） to make the full wave multi scale transform. At the applicable scale, we reconstitute waveform for processing high energy signals and magnifying PP wave. Furthermore, make full use of the characteristics that the wavelet transform remains the time domain, and combine STC with muhiscale method. On the base of the Slowness-Time Correlogram of the reconfiguration waveform, determined is the time of PP wave in the time domain. Reset other waveforms whose frequency is near to the PP wave. The method is more effective in extracting PP wave.
出处
《测井技术》
CAS
CSCD
北大核心
2010年第3期219-222,共4页
Well Logging Technology
