Converted-wave resolution

Abstract

Seismic-resolution theory used in survey design applies to P- and S-wave reflection seismology but is not readily applicable to converted waves. We rederived the theory with sufficient generality to include converted waves explicitly. Generalization of the theory requires that the inherent converted-wave properties of mode change and finite scattering angle be accommodated. The significance of amplitude fidelity in modern seismic applications also affects the resolution description. We considered resolution in the context of a single recorded trace (trace resolution) and an image derived from many traces (image resolution). Trace resolution is governed by wavelet width, which results in a minimum bandwidth requirement, depending on scattering angle and local propagation velocities of incident and scattered modes. Image resolution is governed additionally by the migration acceptance angle and results in minimum aperture and sampling requirements. The requirements for converted-wave surveys generally differ from those of P- and S-wave surveys. Our theory predicts converted-wave reflection seismology resolution and provides the minimum acquisition parameters required to achieve resolution objectives.