Figure 4. Using MakeEPS, final figures can be saved in encapsulated PostScript format. This can then be imported into other popular programs for further editing or incorporation into report text.

What is the Technology behind SeisOptŪ @2D?

SeisOptŪ velocity optimization software achieves a globally optimized velocity model using only first arrival travel time data and array geometry as input. SeisOpt requires no prior assumptions of subsurface structure, or any other subjective data, as input. SeisOpt technology is now being used throughout the world for geotechnical, mining and petroleum applications. The technology is based on a nonlinear optimization method called generalized simulated annealing. The algorithm performs repeated forward modeling, where new models are conditionally accepted or rejected based on a probability criterion. This criterion allows the algorithm to escape from non-unique, local, travel-time minima to achieve a unique, globally optimized model of subsurface velocity structure. The algorithm makes no assumptions on the orientation of the subsurface velocity gradient, and can therefore reveal vertical structures and strong lateral gradients, if present. The method is therefore ideal in areas characterized by strong lateral velocity gradients, and in areas with extreme topography or complex near-surface structure where the user has little or no prior knowledge of subsurface structure.