Non-parametric identification of geological models

Many problems to be solved in geophysical processing can be expressed in terms of identification of spatial geological models: given a function /spl phi/ applied to a geological model /spl gamma/, producing a result R, the problem is to find /spl gamma/* such that /spl phi/(/spl gamma/*)=R*, where R* is the expected result: a seismogram, a pressure curve, a seismic cross-section etc. The presented research deals with the joint use of evolutionary algorithms and Voronoi diagrams to address some non-parametric instances of identification problems in geophysics, i.e. without a priori hypothesis about the geometrical layout of possible solutions. A first application in velocity determination nation for seismic imaging demonstrates the ability of this approach to identify both the geometry and the velocities underground from experimental seismograms.