Kirchhoff migration of field data

Figure 11 shows migrated filed data.

The on-line movie behind the figure shows the migration before and after amplitude gain with time. You can get a bad result if you gain up the data, say with automatic gain or with t², for display before doing the migration. What happens is that the hyperbola flanks are then included incorrectly with too much strength.

The proper approach is to gain it first with $\sqrt{t}$which converts it from 3-D wavefields to 2-D. Then migrate it with a 2-D migration like kirchfast(), and finally gain it further for display (because deep reflectors are usually weaker).

 

wgkirch
Figure 11 Kirchhoff migration of Figure . Press button for movie comparing stack to migrated stack.

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