Wave-equation tomography using image-space phase-encoded data

Wave-equation tomography using image-space phase-encoded data

Claudio Guerra, Yaxun Tang, and Biondo Biondi

Abstract:

Wave-equation tomography in the image-space is a powerful technique that promises to yield more reliable velocity models than ray-based migration velocity analysis in areas of complex overburden. Its practical use, however, has been limited because of the high computational cost. Applying a target-oriented approach and using data reduction can make wave-equation tomography in the image space of practical use. Here, we present results of applying image-space wave-equation tomography in the generalized source domain, where a small number of synthesized shot gathers are generated. Specifically, we generate synthesized shot gathers by image-space phase encoding. This technique can also be used in a target-oriented way. The comparison of the gradients of the tomography objective functional obtained using image-space encoded gathers with those obtained using the original shot gathers shows that those encoded shot gathers can be used in wave-equation tomography problems. Velocity inversion using image-space phase-encoded gathers converges to reasonable results when compared to the correct velocity model. We illustrate our method by applying it to the Marmousi model.

Wave-equation tomography using image-space phase-encoded data