The Kirchhoff migration

[Tingpingbing]

Hello

Please, does anyone understands this figure below?
Do someone here know the difference between Diffraction summing migration and the Kirchoff migration simply explained?

What is the weight factor in the equation?

[GuyM]

The SEG Wiki Pages may help :

https://wiki.seg.org/wiki/Kirchhoff_summation

"The diffraction summation that incorporates the obliquity, spherical spreading and wavelet shaping factors is called the Kirchhoff summation, and the migration method based on this summation is called the Kirchhoff migration. "

So this is a more advanced technique that diffraction migration, as it takes into account kinematic factors relating to how the wave spreads.

Obliquity - making sure the wave propagates in a forward direction
Spherical Spreading - an amplitude (scaling) factor as the energy spreads out in a spherical "shell"from the source
Wavelet shaping - making sure as the wavelet is spread out along the diffraction shape (by Huygen's principle) the shape of the wavelet is rotated

[Tingpingbing]

Thank you so much, GuyM. You have helped me alot

[GuyM]

Well - I'm mostly pointing you to the SEG Wiki, which is mostly Oz Yimaz's book. If you can get hold of a copy it will be a big help.

[Trinder]

A method of seismic migration that uses the integral form (Kirchhoff equation) of the wave equation. All methods of seismic migration involve the backpropagation (or continuation) of the seismic wavefield from the region where it was measured (Earth's surface or along a borehole) into the region to be imaged.