Study on reflection spherical wave at the near surface

Abstract

Abstract In real seismic surveys, seismic wave propagates in the form of spherical wave and plane wave is the approximations of spherical wave in the far-field and for high frequencies. The traditional seismic processing and interpretation methods based on the plane wave theory are not exact. Furthermore the difference between the plane wave and spherical wave is strong, especially in the near surface. Studying the characteristics of reflection spherical wave near the surface can develop more accurate wave theory. In this paper, a two-layer model with a high-velocity upper layer is built to analyze the spherical reflection wave characteristics. Tests show when the incident angle reaches a certain level, there will be an irregular wave, the pseudo-spherical wave, following the main reflection spherical wave, which has a great influence on the main reflection wave. This discovery has enriched our understanding of wave propagation theory and it has important guiding significance for accurate study on wave phenomena.