Seismic angle tomography

One of the main challenges in seismic imaging is the estimation of sufficiently accurate background velocity models in the presence of complex geology. In this paper we show the use of a differential semblance in angle or DSA (Symes and Carazzone, 1991; Brandsberg-Dahl et al., 2003) misfit function to perform ray-based angle tomography on PP and its extension to PS reflection events. This measure is optimal as it is the only measure that depends smoothly on the velocity model.