## Effect of caustics on the ray-based Born approximation

**Libor Sachl**
### Summary

3D P-wave synthetic seismograms in several 2D isotropic heterogeneous
models have been computed using the first-order ray-based Born
approximation and the ray theory. The Born approximation
is computed in a 2D grid, and the background model is a 2D smooth
heterogeneous isotropic velocity model. The seismograms have been
computed for the total number of 37 receivers. The strange wavegroups
are observed in the Born seismograms. The explanation is that these
problems are caused by caustics on the direct wave. Three solutions
are proposed. Seismograms corrected using one of these solutions
are shown. Furthermore, particular wavegroups present in the Born
seismograms and missing in the ray-theory seismograms are discussed.

### Whole paper

The paper is available in
PDF (2813 kB).

In: Seismic Waves in Complex 3-D Structures, Report 22,
pp. 55-82, Dep. Geophys., Charles Univ., Prague, 2012.