To estimate the P-S separation coefficients I use a different type of objective function. The energy in the P-s and S-p panels is not a suitable measure because we expect to observe converted waves with significant amplitudes.

A human looking at a gather containing P and S waves often uses the moveout of the events to discriminate between then. With this in mind I have chosen to use an objective function that is calculated in constant velocity stack space. If a section contains only upcoming P waves we would expect to see significant amplitudes at P-p and S-p velocities but none at S-s velocities. A section containing only upcoming S-waves should only have energy at S-s and P-s velocities.

To use this separation procedure a set of velocity ``corridors'' must be defined. These corridors define the regions in time/velocity space in which the different event types are expected to occur.

There are several possible objective functions that can be used to estimate the best separation parameters.

- F1 = Minimize energy in ``wrong'' part of velocity space.
- F2 = Minimize the ratio of energy on ``wrong'' part of velocity space to energy in ``right'' part of velocity space.
- F3 = Minimize the cross correlation of the S-S and P-P velocity panels within the P-P and S-S corridors.

12/18/1997