小波包变换在面波分离中的应用

作为一种时频分解方法，小波包变换有着广泛的用途，它不仅优于小波变换，而且与传统Fourier变换相比，它能刻画出具有相同频率的有效波与面波在时间一空间域的分布，然后可以从中分离面波，再进行重构，即可得到分离面波后的结果，该方法在成功分离面波的同时，可使有效波的能量（尤其是其低频能量）损失减小，有效地保持信号的频宽不变，提高记录的信噪比。实际资料的处理结果表明，此方法在分离面波方面具有良好的效果。

THE APPLICATION OF WAVELET PACKAGE TRANSFORM TO SURFACE WAVE SEPARATION

As a time-frequency decomposition method,the wavelet package transform can be used extensively.It is better than the wavelet transform.The wavelet package transform can divide the seismic data in more detail and better describe the distribution of effective wave and surface wave in the time-space field with the same frequency compared with the conventional Fourier transform.In addition,we can separate the surface waves from it.After reconstruction we can get the result of surface wave separation.The new method can separate surface waves successfully,and meanwhile it can also avoid the loss of the effective wave energy(particularly the low frequency energy),preserve the frequency band width of signal and raise the signal/noise ratio of the seismic data.Practice shows that it is very effective in surface wave separation.