Analysis on dispersion and alias in finite-difference solution of wave equation

作者：Sun Cheng Yu^*; Gong Tong Ju; Zhang Yu Liang; Zhang Wen Ying

来源：Oil Geophysical Prospecting, 2009, 44(1): 43-48.

• Alias
• Finite difference
• Finite-difference solutions
• Folding frequency
• For-ward simulations
• High-frequency components
• Peak frequencies
• Quantitative analysis
• Spatial samplings
• Theoretical studies
• Zero frequencies

The finite-difference operation of wave equation appears inevitably the phenomenon of numeric dispersion, seriously interfering forward simulation results of wavefield. Through theoretical study of dispersion issue in finite-difference solution of wave equation and quantitative analysis on the influence of spatial sampling interval, propagating distance and velocity on dispersion, the paper pointed out the alias phenomenon resulted from dispersion and main characters and proved the studied conclusions by numeric case and model forward simulation: the dispersion makes the velocity of high-frequency component become slow and propagating velocity of zero-frequency component equals to the true velocity of strata; in aspect of suppression of dispersion, using 8th-order precision finite-difference format can reach the unification of precision with efficiency and it should not less 7 samples within the wavelength relative to used peak frequency of source wavelet; discrete difference makes folding frequency ahead and it should pay more attention to suppression of dispersion and prevention of alias production for the strata with lower velocity.

• 出版日期2009
• 单位中国石油大学（华东）