THE CHOICE OF INITIAL APPROXIMATION (REFERENCE VELOCITY DISTRIBUTION) IN ITERATION KINEMATIC SEISMOTOMOGRAPHY

Abstract

Kinematic seismotomography is based on the inverse kinematic problem (IKP). It uses kinematic characteristics of wave process to solve its problems: velocity of propagation of oscillations in the medium and arrival times of the corresponding waves. Traditional tomographic algorithms based on inverse integral transformations are not applicable in seismic practice (in particular, owing to incompleteness of projection data). However, iteration methods of algebraic reconstruction allow us to realize the method of computational (computer) tomography (CT) in kinematic seismics. This method is distinguished for its significantly better informative properties compared to the other methods of computational diagnostics. In the organization of iteration procedures, the key aspect is the choice of the initial approximation. In this work, we suggest a new approach to the determination of the reference velocity distribution (initial approximation) for iterative methods in kinematic seismotomography based on the optimization of the parameters of this distribution and the information about the elements of the projection matrix (results of measurements).