Plane-wave migration in tilted coordinates |

Most existing one-way wave-equation migration algorithms have difficulty in
imaging steep dips in a medium with strong lateral velocity variation.
We propose a new one-way wave-equation-based migration, called ``plane-wave
migration in tilted coordinates.'' The surface data are converted
to plane-wave source data by slant-stacking processing, and each resulting plane-wave source dataset
is migrated independently in a tilted coordinate system with an extrapolation direction
determined by the source plane-wave direction at the surface.
For most waves illuminating steeply dipping reflectors,
the extrapolation direction is closer to their propagation direction in the
tilted coordinates. Therefore, plane-wave migration in tilted coordinates can correctly image
steeply dipping reflectors, even by applying one-way extrapolators.
In a well-chosen tilted coordinate system, waves that overturn in conventional vertical Cartesian coordinates
do not overturn in the new coordinate system. Using plane-wave migration in tilted coordinates,
we can image overturned energy with much lower cost compared to reverse-time migration.

- Introduction
- One-way wave equation migration
- Plane-wave source migration
- Wavefield extrapolation in tilted coordinates
- Plane-wave migration in tilted coordinates
- Numerical examples
- An exploding-reflector dataset with overturned waves
- Impulse responses
- BP 2004 velocity benchmark dataset

- Conclusion
- Acknowledgments
- Bibliography
- About this document ...

Plane-wave migration in tilted coordinates |

2007-09-18