【摘要】 改进了用于模拟地震波场的傅里叶拟谱微分方法,改进后的方法精度是常规拟谱方法的4倍,称为改进的傅里叶拟谱方法.在较高数值精度的一阶应力-速度弹性波动方程的基础上,采用该方法和常规拟谱方法对Marmousi模型进行数值求解,结果表明,该方法的数值频散效应明显比常规拟谱方法弱.将该方法与有限元方法在各向异性介质中进行模拟比较,发现该方法的精度接近有限元方法,数值频散效应比有限元方法明显减小,而且可在较大空间网格间距下进行计算,从而提高计算效率.在3-D非均匀介质中的地震波传播数值模拟结果表明,该方法是一种研究复杂非均匀介质中地震波传播问题的高效方法.更多还原

【Abstract】 A new fast differentiation operator,"pseudospectral time-staggered difference operator",is proposed in this paper.The accuracy of this method is four time of the normal pseudospectral method.It is confirmed that the numerical dispersion of this method is less than that of normal pseudospectral method by comparing the calculation result of Marmousi model.The new operation is applied to simulate seismic wave propagation in 3-D heterogeneous medium,and the results show that the time-staggered difference operator for the pseudospectral method is valid for the seismic wave simulation in the complex heterogeneous medium.更多还原