Topic:
How to normalize the amplitudes of one survey to the amplitudes of another survey.

Description:
Had three 3D seismic surveys in distinct projects.

We had different CDP/Line numbering, and are interested in merging them to
just one survey. In order to do this process, we renumbered the CDPs/lines,
reloaded one survey (because it had different sample rate than the others) and
merged all of them. 

Everything was working fine until we generated a time slice.
The time slices were available to the major part of the survey, but they are not
available in the area belonging to one of the old surveys.

In this area we can't see the slices, but are not receiving any error messages.
The screen layout of the time slice window appears, but without data (blank).

Does anybody know what can be happening?

Solution:
First thought is to use manual display scaling to play with some extreme
numbers. The possibility is that you have some extremely large amplitude values.

Use the SHIFT /MB1 combination to examine the amplitudes of the time slice in
the dead area. Slices are always scaled by survey RMS. By default lines are
scaled trace to trace so you'd never notice such a problem.

Second thought is to normalize(balance) the amplitudes of all surveys before you
merge them. This is done in Computation Manager > Amplitude Normalization.

1.) Computation Manager > Seismic Processing > Amplitude Normalization.
    For Normalization type, select 'Seismic Reference', the recommended
    Reference type is 'RMS', then select the reference survey and class 
    to which you want to normalize. Click OK.

2.) In the upper left corner click the Survey button.  Select the
    survey on which you want to perform the normalization, the input class
    and assign it a new output class. Click OK.

3.) Start.

Once the normalization is complete, set the posting order in Seis2DV/3DV to
display the new normalized class of data just created.

In Seis2DV/3DV

4.) Define > Display Specs
    Set the Non-existent data uses to Class Priority. Click OK.

5.) Define > Class Priority
    Choose the new class from the available class list and click the top
    button to make sure that this new class is on top of the old class of
    data in the Class Priority box. Click OK.





Last Modified on: 19-MAY-00