Generalization of the Vertically Heterogeneous Velocity Models

I propose a power-gradient velocity model which incorporates several well-known velocity models as special cases. The proposed velocity model covers wide range of possible velocity distributions and has four parameters, which gives more flexibility in velocity-model manipulation. For the proposed non-linear velocity model, I compute the kinematical characteristics: offset-traveltime parameteric equations, traveltime parameters, relative geometrical spreading and the phase of the propagator. The kinematical characteristics are investigated with respect to a parameter responsible for non-linearity of velocity distribution. The inversion of traveltime parameters is discussed in three- and four-parameter framework.