Insights into migration in the angle domain

Abstract

We examine some aspects of the Kirchhoff migration in the angle domains. The angle domains we refer to are the scattering angle domain (both opening and azimuth of scattering), which replaces the surface related offset and azimuth of acquisition, and the illumination dip angle domain (having two components in 3D). We examine the insight given to the Kirchhoff summation and to the stationary phase approximation, by virtue of the decomposition of the migration in the illumination dip angle domain. Additionally we point out some differences between angle domain and offset domain migration.

PS imaging of ocean-bottom data

“…The dip-angle range for both PP and PS is -45° to 45° with a 2°-angle bin sampling. Decomposing migrated images according to the local dip-angle domain (Ravve and Koren, 2011) has proved to be of practical use for illumination analysis in asymptotic (Audebert et al, 2002) and full-wavefield imaging (Li et al, 2012).…”

Post‐stack velocity analysis in the dip‐angle domain using diffractions

“…The procedure for generating these common-image gathers is described by Audebert et al (2002) and Reshef and Rueger (2008). We chose to use here the dip-angle common-image gathers.…”

“…It means that there is no practical way to use the reflections in this domain for velocity analysis. Unlike the asymmetric shape of the concave reflections, which is related to their dip (Audebert et al 2002), the asymmetry of the diffractions is due to the lateral velocity variations and the location of the common-image gather with respect to the diffractor(s). 5.…”

High Resolution/High Fidelity Seismic Imaging and Parameter Estimation for Geological Structure and Material Characterization

“…Therefore the imaging and image amplitude correction have to be done in the angle-domain, which makes ray-based methods more convenient than wave-equation based methods since the angle information is inherently embedded in ray-based methods. The theory and method of true-reflection imaging has been developed based on high-frequency asymptotic theory (ray theory) and is traditionally carried out through Kirchhoff prestack depth migration (e.g., Bleistein et al, 1987;Hubral et al, 1991;Hanitzsch, 1995;Xu et al, 2001;Audebert et al, 2002;Brandsberg-Dahl et al, 2003). However, the results may contain large errors in complex areas due to the high-frequency approximation and singularity problems therein.…”