地震信号的时域模拟

目前获得的地震波数据大都是以加速度时程形式给出的，直接积分获得的速度时程和位移时程往往存在着明显的基线漂移现象．简便的时域优化校正算法是一种较好的选择．提出了一种分步时域校正法．首先基于最小二乘法以三阶多项式形式来拟合加速度的非零曲线，对原始加速度时程做基线预校正处理；其次对于校正后的积分速度和位移曲线仍存在的长周期基线波动问题，将校正后的加速度曲线代入单自由度系统地震反应递归公式，从而生成地震波的速度时程和位移时程．该方法原理简单，实施方便，而且能够很好地消除速度波和位移波的漂移现象．

Time Domain Simulation of Seismic Signals

The present seismic wave data is given in the form of acceleration time history; and the velocity and displacement time histories obtained by direct integration exist obvious baseline drift. Time-domain optimal regulation method is a better choice for us. A time-domain regulation method of fractional steps is proposed. First, the original acceleration time history is precorrected by using the third order polynomials to fitting the nonzero curve; second, for the corrected integral velocity and displacement curves still existing long period baseline drift, substituting the corrected acceleration curve into recursive formula for calculating seismic response of single-degree-of-freedom system, the velocity and displacement time histories of seismic wave are generated. With its simple principle and easy implementation, the proposed method can eliminate baseline drift of velocity and displacement time histories.