【摘要】 使用小波函数解决三角级数法合成人工地震波过程中无法表述地震波局部性质的缺陷。首先对三角级数法合成人工地震波的过程进行论述,目的是找出三角级数法的缺陷;然后说明了如何使用小波函数对目标功率谱进行了小波分解,使用分解后的高频小波基乘以随机相位的余弦函数,从而合成了人工地震波,并对如何计算目标功率谱进行了详细的说明;最后用实例验证了此方法比三角级数法优越,而且比较了使用不同小波基对合成人工地震波的影响。使用Daubechies小波基(db4)比使用Daubechies小波基(db1)合成人工地震波效果好,而小波函数层数增加并不能有效的提高合成人工地震波的精度。更多还原

【Abstract】 When using the trigonometric series method to generate artificial seismic wave, the usually appearing problem is that the method can not account for the local defect of seismic wave. The process of generation was analysed and the defects of trigonometric series method were demonstrated. Wavelet functions were employed to transform the target power spectrum and the high frequency wavelet bases multiplied by cosine function with random phase were adopted to generate artificial seismic wave. How to calculate the target power spectrum more accurately was explained. An example was given to illustrate the better properties of the new method the effects of different wavelet bases to generate artificial seismic wave were compared. The conclusion is that Daubechies wavelet Db4 is better than Daubechies wavelet Db1 to generate artificial seismic wave, and increasing the layers of wavelet function can not improve the precision.更多还原