Abstract: The reconstruction of seismic wave-speed distribution is nonlinear. Seismic ray path is calculated by using a model of the square of slowness. A parameterization of the model based on first order B-splines provides nonnegative matrix of the linear systems. In order to improve the solution stability, a damped, and weighted least-square procedure is proposed for considering the priori information of ray distribution. It gives numerical modelling examples as well.

Key words: tomography, least-square solution