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Angle decomposition


cwgat Figure 2. (a) Model showing one shot over multiple reflectors dipping at $0^\circ$ , $15^\circ$ , $30^\circ$ , $45^\circ$ and $60^\circ$ . The vertical dashed line shows a CIG location. Incidence ray is vertically down and P to S conversions are marked by arrowed lines pointing away from reflectors. (b) Converted wave angle gather obtained from algorithm described by Sava and Fomel (2006a). Notice that converted wave angles are always smaller than incidence angles (in this case, the dips of the reflectors) except for normal incidence.

cwgat
Figure 2. (a) Model showing one shot over multiple reflectors dipping at $0^\circ$ , $15^\circ$ , $30^\circ$ , $45^\circ$ and $60^\circ$ . The vertical dashed line shows a CIG location. Incidence ray is vertically down and P to S conversions are marked by arrowed lines pointing away from reflectors. (b) Converted wave angle gather obtained from algorithm described by Sava and Fomel (2006a). Notice that converted wave angles are always smaller than incidence angles (in this case, the dips of the reflectors) except for normal incidence.

As indicated earlier, the main uses of images constructed using extended imaging conditions are migration velocity analysis (MVA) and amplitude versus angle analysis (AVA). Such analyses, however, require that the images be decomposed in components corresponding to various angles of incidence . Angle decomposition takes different forms corresponding to the type of wavefields involved in imaging. Thus, we can distinguish angle decomposition for scalar (acoustic) wavefields and angle decomposition for vector (elastic) wavefields.

Subsections

Next: Scalar wavefields Up: Yan and Sava: Angle-domain Previous: Imaging with scalar and

2013-08-29