Preconditioned prestack plane-wave least squares reverse time migration with singular spec

Preconditioned prestack plane-wave least squares reverse time migration with singular spectrum

constraint

Li Chuang;Huang Jian-Ping;Li Zhen-Chun;Wang Rong-Rong

【期刊名称】《应用地球物理（英文版）》 【年(卷),期】2017(014)001

【摘要】Least squares migration can eliminate the artifacts introduced by the direct imaging of irregular seismic data but is computationally costly and of slow convergence.In order to suppress the migration noise,we propose the preconditioned prestack plane-wave least squares reverse time migration (PLSRTM) method with singular spectrum constraint.Singular

spectrum

analysis

(SSA)

is

used

in

the

preconditioning of the take-off angle-domain common-image gathers (TADCIGs).In

addition,we

adopt

randomized

singular

value

decomposition (RSVD) to calculate the singular values.RSVD reduces the computational cost of SSA by replacing the singular value decomposition (SVD) of one large matrix with the SVD of two small matrices.We incorporate a regularization term into the preconditioned PLSRTM method that penalizes misfits between the migration images from the plane waves with adjacent angles to reduce the migration noise because the stacking of the migration results cannot effectively suppress the migration noise when the migration velocity contains