Multiples model

First, we need to obtain the multiples model. For this we create an operator that represents the reflection from the water surface to the water bottom and back (Figure ) We obtain the operator from the data itself, by considering the watter bottom a flat surface. We begin by isolating the first arrival, we then upward continue the first arrival to the water surface level.

 

sketch Figure 1 Multiple operator. An OBC acquisition with the source at the surface and the receivers at the bottom. For this shallow experiment the water-bottom multiple is the most dominant multiple.

Figure  shows the comparison of one gather of our multiples model with the data itself. The left side shows the multiples model and the right the data. Observe the good correlation between our data and the multiples model, not only at zero offset, but also in the moveout at far offset.

 

mult.model Figure 2 Multiples model compared against the data set. Left side corresponds to the data and right side to multiple model for the water-bottom.