## Interpolation of the coupling-ray-theory Green function
within ray cells.

**Ludek Klimes** and
**Petr Bulant**
### Abstract

The coupling-ray-theory tensor Green function for elastic S waves
is frequency dependent, and is usually calculated for many frequencies.
This frequency dependence represents no problem for calculating the Green
function, but may be impractical or even unrealistic in storing the Green
function at the nodes of dense grids, typical for applications such as
Born approximation or non-linear source determination.

We have already proposed the approximation of the coupling-ray-theory
tensor Green function, in the vicinity of a given prevailing frequency,
by two coupling-ray-theory dyadic Green functions described by their
coupling-ray-theory travel times and their coupling-ray-theory amplitudes.

The above mentioned prevailing-frequency approximation of the coupling ray
theory enables us to interpolate the coupling-ray-theory dyadic Green
functions within ray cells, and to calculate them at the nodes of dense grids.
For the interpolation within ray cells, we need to separate the pairs
of the prevailing-frequency coupling-ray-theory dyadic Green functions
so that both the first Green function and the second Green function
are continuous along rays and within ray cells. In this contribution,
we describe the current progress in this field and outline the basic
algorithms. We also demonstrate the preliminary numerical results
in several velocity models.

### Whole paper

The paper is available in
PDF (509 kB).

In: *Expanded Abstracts of 15th Int. Congress of the Brazilian
Geophysical Society (Rio de Janeiro 2017) (CD-ROM)*,
8332017013112395 (6 pp.), Brazilian Geophysical Society, ISSN 2175-4551.

SW3D
- main page of consortium ** Seismic Waves in Complex 3-D Structures **.