A 17-point difference scheme for 2D frequency-domain elastic wave and modeling
YUE Xiao-Peng1, 2, BAI Chao-Ying1, YUE Chong-Wang1
1.College of Geology Engineering and Geomatics,Chang’an University,Xi’an 710064,China; 2.School of Mathematics and Statistics,Xuchang University,Xuchang 461000,China
Abstract:The 2D elastic wave frequency domain 17-point difference scheme is obtained based on the simplified 25-point difference scheme so as to optimize the structure of impedance matrix,reduce required memory and improve efficiency in 2D isotropic media forward.This scheme recalculates partial differential operators in the elastic wave equation,reduces the grid node in calculation process,and constructs the forward matrix equation with optimized impedance matrix.The P-wave and S-wave velocity dispersion formulae are derived,the dispersion curves of different Poisson's ratio are given,and the grid number requirement in each horizontal wave length is given with phase velocity error range being ±1%.The frequency dispersion curve and numerical simulation of the wave field snapshots and seismic records show that the 17-point difference scheme has slightly strict grid spacing requirements, similar accuracy,slightly less computation time and smaller impedance matrix bandwidth in comparison with 25-point difference scheme.