Velocity Analysis of Early Results: Direct Wave Fields

We may now apply the velocity filter to identify and separate wave-fields. Both frequency and polarization filters are well established in Rock Physics laboratory work. With the velocity filter, we may identify:

• Direct arrivals as in a surface seismic refraction shoot.
• 'Upgoing' and 'downgoing' wave-fields with linear moveout, as in a VSP survey.
• Cross-specimen reflected waves with hyperbolic moveout, or Normal Move Out (NMO).

Also, we have the intriguing possibility of measuring Amplitude Versus Offset (AVO) effects directly in the Rock Physics Laboratory.

Direct wave: P&S velocities		Debias and tzero: P-cone
P:S :: 1.624:1 measured on direct wave fields

Reflected Wave Fields >>