本文的研究目的是解决这下问题: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。本文的研究方法是: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。本文的研究结论是: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。
The aim of this page is as follow: based on wavelet function, to solve the questions, which is that the trigonometric series method can not account for the local defect of seismic wave when using it to generate artificial seismic wave. The research methods of this page are as follow: Firstly, this page explains the process of generating artificial seismic wave based on trigonometric series method. The aim is to show the defect of this method. Secondly, this page explains how to use wavelet function to transform target power spectrum into wavelet base. Then high frequency wavelet base multiplied by cosine function with random phase to gen rate artificial seismic wave. And this page explains how to calculate the target power spectrum accurately. Thirdly, An example is gave to explain the better properties of this method as trigonometric series method to generate artificial seismic wave. And this page compare with the effect of different wavelet base to generate artificial seismic wave. The conclusion is that Daubechies wavelet transform (db4) is better than Daubechies wavelet transform (db1) to generate artificial seismic wave. And it can not improve precision to increase the layer of wavelet function.