Sigsbee model is often used as a benchmark for migration/inversion algorithms due to its geological complexity. The data was modeled by simulating the geological setting found on the Sigsbee escarpment in the deep-water Gulf of Mexico. The model exhibits illumination problems due to the complex salt shape, with a rugose salt top.
When the subsurface is complex, migration operators produce images with reflectors correctly positioned but biased amplitudes Kuehl and Sacchi (2001); Prucha et al. (2000). That is why an inversion formalism Tarantola (1987) needs to be used to account for that problem.
In this paper, we apply the target-oriented wave-equation inversion idea presented in Valenciano et al. (2005) to the Sigsbee data. Due to the complex velocity structure and the limited acquisition cable length, the reflectors are not illuminated from all reflection angles. That highlights the need of a more sophisticated regularization in the angle domain Kuehl and Sacchi (2001); Prucha et al. (2000); Valenciano and Biondi (2005) than the simple damping proposed by Valenciano et al. (2005).