摘要：Multidimensional Fourier transform on an irregular grid is a useful tool for various seismic forward problems caused by complex media and wavefield distributions. Using a shape -function-based strategy, we have developed four different algorithms for 1D and 2D nonuniform Fourier transforms, such as two high-accuracy Fourier transforms (the linear shape-function based Fourier transform [LSF-FT] and the quadratic shape -function-based Fourier transform [QSF-FT]) and two nonuniform fast Fourier transforms (NUFFTs) (the linear shape-function based NUFFT [LSF-NUFFT] and the quadratic shape -function-based NUFFT [QSF-NUFFT]), respectively, based on their linear and quadratic shape functions. The main advantage of incorporating shape functions into the Fourier transform is that triangular elements can be used to mesh any complex wavefield distribution in the 2D case. Therefore, these algorithms can be used in conjunction with any irregular sampling strategies. The accuracy and efficiency of the four nonuniform Fourier transforms are investigated and compared by applying them in frequency-domain seismic wave modeling. All of the algorithms are compared with the exact solutions. Numerical tests indicate that the quadratic shape-function-based algorithms are more accurate than those based on the linear shape function. Moreover, LSF-FT/QSF-FT exhibits higher accuracy but much slower calculation speed, whereas LSF-NUFFT/QSF-NUFFT is highly efficient but has lower accuracy at near-source points. In contrast, a combination of these algorithms, by using QSF-FT at near-source points and LSF-NUFFT/QSF-NUFFT at others, achieves satisfactory efficiency and high accuracy at all points. Although our tests are restricted to seismic models, these improved NUFFT algorithms may also have potential applications in other geophysical problems, such as forward modeling in complex gravity and magnetic models.

ISSN号：0016-8033

卷、期、页：卷: 86期: 4页: T165-T178

发表日期：2021-07-01

影响因子：2.608800

期刊分区（SCI为中科院分区）：三区

收录情况：SCIE（科学引文索引网络版）,地学领域高质量科技期刊分级目录（国外T1）

发表期刊名称：GEOPHYSICS

参与作者：戴世坤,Chen, Longwei

通讯作者：欧阳芳

第一作者：赵建国,王尚旭

论文类型：期刊论文

论文概要：欧阳芳,赵建国,戴世坤,Chen, Longwei,王尚旭，Shape-function-based nonuniform Fourier transforms for seismic modeling with irregular grids，GEOPHYSICS，2021，卷: 86期: 4页: T165-T178

论文题目：Shape-function-based nonuniform Fourier transforms for seismic modeling with irregular grids